Development and Applications of Aberration Corrected Environmental STEM (AC ESTEM) for Dynamic In-Situ Reaction Studies of Nanoparticle Catalysts

Lead Research Organisation: University of York
Department Name: Physics

Abstract

We propose to create in the UK a novel research capability providing Angstrom Analysis for dynamic in-situ reaction studies under controlled conditions of temperature and continuous gas atmosphere rather than the usual high vacuum. The new design provides the world's first full function aberration corrected environmental scanning transmission electron microscope (AC ESTEM). In association with partners in the vibrant UK chemical and energy industries we will generate fundamental application science underpinning nanoparticle based solid state heterogeneous catalysis used in gas-solid reactions. We will modify an existing AC TEM/STEM instrument to complement and extend with gas reaction studies the National AC STEM Facility's superior image and energy resolutions in high vacuum. It will be used in York programmes and collaborative projects with other groups through the AC STEM. It builds on the PIs' established reputations for global leadership in ETEM, with most of the worldwide activity to date - all overseas - based on >10 high resolution ETEMs and many of them AC (on the TEM image side only), using core technology from the authors' earlier developments. Preliminary 'proof-of-principle' has been demonstrated on the remotely controlled double aberration corrected JEOL 2200FS TEM/STEM at York; combining sub-Angstrom (<0.1nm) resolution, unrestricted HAADF Z-contrast STEM imaging, wide angle electron diffraction and EDX (+ EELS) chemical analysis not available on ETEMs. The double aberration correction collects, in a single and often directly interpretable TEM image, a full range of spatial frequencies at close to zero defocus to minimise image delocalisation at internal interfaces such as grain boundaries, external surfaces, defects and other key discontinuities. This is especially important for dynamic in-situ studies with continuously changing data making impractical older through-focal series reconstruction methods. AC also transforms the sensitivity of STEM analysis. The work will use analytical methods established with 'frozen' and process extracted samples, and apply them to the study of continuous processes at new levels of sensitivity and relevance. Access to key intermediate states and phases may be critical to understand and control process mechanisms; but they may be metastable with respect to conditions, including temperature or chemical environment, and therefore not accessible through ex-situ or pulse studies. A very practical example, in which there is leading UK industry interest and support, is the nano-structure and related property stability of supported metal nanoparticle heterogeneous catalysts. Through synthesis, activation, operation, deactivation, reactivation and recovery mechanisms, understanding at a fundamental level is critical for managing on a rational basis industrial practice for sustained activity and selectivity; and where necessary recovering these key attributes when lost. The project direction is closely aligned with the domain science needs of real world academic and industrial applications, and there are early adoption prospects for underpinning key technologies; including to extend useful process life cycles. For example, this is critical for the wider commercial viability of fuel cells. The proposal has the support of leading UK companies in the vibrant and internationally competitive chemical industry sector, and of academic collaborators. At the same time, the new learnings in basic domain science are also directed towards opening up new applications of pressing societal value in the environment. Fundamental physical science research with strategic and tactical industrial applications leads to differentiated intellectual products with an initiative unique in the UK and fully competitive globally. The project will extend and apply core nanoparticle catalysis science and technology, and train a new cohort of students, postdocs, senior staff and visitors.

Planned Impact

The project introduces to the UK AC ETEM and to the World full function AC ESTEM, in combination as AC (E(S)TEM), with a continuous controlled gas environment around the specimen for dynamic in-situ reaction studies of heterogeneous nanoparticle catalysts and related materials. AC ESTEM will have 0.1nm resolution HAADF Z-contrast imaging with single atom sensitivity, EDX chemical analysis and wide angle electron diffraction with CBDP. This will complement and extend application specific technical capabilities of the established EPSRC National Facility for high performance AC STEM and will be co-ordinated with that programme. We will work with partners in UK academia to provide wider access in the UK to the innovative new capability. Our project is focused on new methods of fundamental science applied to important heterogeneous catalyst technology applications in collaboration with leading British companies, whose expertise, interests and needs are contributing significantly to the planning, implementation, development and exploitation of the project initiative. The original partners, providing CASE studentships, are the catalyst businesses of Johnson Matthey and BP. Discussions with Shell are at an earlier stage. All three companies have staff involved with the laboratory work, the provision of materials synthesised for specific designs of experiment, access to other characterisation methods and broad catalyst performance characterisation. This means we can leverage resources and expertise without the need to establish them ourselves, and more effectively expose our students and staff to well established practices. The impact for each company will include (a) direct and specific tactical support for technology developments, (b) targeted background domain science, in some cases pre-competitive, to inform longer term strategic decisions, and (c) reputational association with the project, (d) results from it and where appropriate to refer problems to it. There is scope for new and more effective solutions to long standing problems in the chemical industry, new energy initiatives, in the environment and in remediation. The whole of Society (the people, companies and Government) stands to benefit above and beyond immediate operational profit in terms of lower cost and more efficient energy systems, cleaner emissions, more efficient, lower cost and more complete chemical reaction processes, with less waste products, and generally more stable and benign operations. The project needs to engage with all stakeholders to define and to implement beneficial solutions to underlying problems. Everyone benefits from new products and better chemical production processes with reduced waste and energy requirements. We propose to hold focus groups and targeted meetings to promote the agenda and generally to extend the benefits of the research. We will engage with wider activities of outreach. A major activity for which some funding support is requested, is to engage with the world wide scientific community by attending international conferences, especially in Europe, the US and Asia. We are organising sections of the next European Microscopy Congress, to be held in Manchester in Sept 2012, and if we are successful with funding this will be a suitable occasion for a very public launch of the project. We have established with each company pathways for interactions at the tactical, laboratory scale, and strategically at more senior corporate levels; informed by our own experiences at senior technical levels on major projects in (US) industry (see cvs). The most immediate impacts will be directly with the sponsoring organisations to inform decisions about current practices and future technology developments. This will be achieved by close contact in meetings, and in joint laboratory work, with senior management and technical staff from each company separately; and together at the pre-competitive stage.

Publications

10 25 50

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Boyes ED (2020) Visualizing single atom dynamics in heterogeneous catalysis using analytical in situ environmental scanning transmission electron microscopy. in Philosophical transactions. Series A, Mathematical, physical, and engineering sciences

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Boyes ED (2020) Single Atom Dynamics in Chemical Reactions. in Accounts of chemical research

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Gai PL (2020) Dynamic in situ microscopy relating structure and function. in Philosophical transactions. Series A, Mathematical, physical, and engineering sciences

 
Title images 
Description award interviews by media: TV, Newspapers, Radio. 
Type Of Art Image 
Year Produced 2013 
Impact L'Oreal-UNESCO award interviews by media: TV, Newspapers, Radio. Our research has been featured in the global science media, with feature articles in in Chemistry World (Royal Society of Chemistry), Chemical & Engineering News (American Chemical Society), Materials Research Society (USA), New Scientist, Royal Australian Society of Chemistry, University of Delaware in UDel News (USA), BBC Radio (4,5, world service), BBC Radio York, BBC Radio Birmingham, British media papers including Times Higher Education Supplement (THES), Science podcast of The Guardian; York Press, Oxford Mail, Oxford Times and Oxford Guardian; Girton College Cambridge; and French main TV channel TF1; TV and media in several other countries. Also publicity through L'Oreal pages in international and women's magazines as well as the international press. 
 
Description Environmental STEM (AC ESTEM) for Dynamic In-Situ Reaction Studies of Nanoparticle Catalysts
EP/J018058/1
by Professor Pratibha L. Gai (PI), and Professor Edward D. Boyes (CoI), University of York

In chemical technology heterogeneous catalysts consisting of nano-scale particles operate in gas atmospheres and at elevated temperatures. Cutting edge fundamental science is needed to understand and improve performance of the behaviour of these catalysts in controlled reaction environments, to support internationally competitive chemical process industries in the UK.

As part of our EPSRC award EP/ EP/J018058/1, we have developed, for the first time globally, aberration corrected environmental scanning transmission electron microscopy (AC ESTEM) instrumentation. This project has established in the UK the world's first atomic resolution (AC) E(S)TEM capability and we are making it increasingly widely available to colleagues in the UK and in collaborations internationally. The AC ESTEM capabilities include, atomic scale imaging and analysis under controlled conditions of gas environment around the specimen held at high temperature. The new facilities operate under a sub set of realistic reaction conditions with single atom sensitivity. Include are Z-contrast high angle annular dark field (HAADF) STEM imaging, energy dispersive x-ray chemical analysis and wide angle electron diffraction (including CBDP), as well as electron energy loss spectroscopy (EELS). The project is designed to generate for the first time and in close collaboration with the vibrant UK catalysis and chemicals industry, fundamental and practical atomic scale understanding of key preparative, activation, reaction, deactivation and where practical reactivation processes. Analysis of real world practices show considerable scope for improvement in deploying resources, including the amount of precious metals needed for automotive exhaust emissions controls.

Our novel AC ESTEM development is enabling research on gas-solid reactions with single atom resolution in many technologically important chemical reactions which were hitherto unknown. Training of students and young researchers is being carried out.
Collaborations with other UK Universities including White Rose Universities and the UK chemical and energy industries are in progress. Several joint publications have resulted.
The research has received international recognition with the award of L'Oreal-UNESCO women in science award as the 2013 Laureate for Europe for Prof Pratibha Gai (one female scientist is selected from each continent); elections to the Fellowships of the Royal Academy of Engineering; The Institute of Physics, The Institute of Materials, Minerals and mining and so on. Professor Gai also received the prestigious national honour and was appointed a Dame (DBE) for services to Chemical Sciences and Technology in 2018 New Year Honours List.
In 2018, Professor Pratibha Gai has been awarded Honorary Fellowship of the Royal Microscpical Society and Honarary Fellowship of Girton College, University of Cambridge.

Recently, in 2019, Professor Dame Pratibha Gai and Prof Edward Boyes have been awarded Fellowships of the Microscopy Society of America.
Professor Dame Pratibha gai, FRS, Prof Ed Boyes and colleagues have organised a research meeting on in-situ microscopy at the Royal Society, London in October 2019. Based on the novel in-situ ESTEM instrument development work of Professor Boyes and Professor Gai, the York Nanocentre at the University of York has been successful with an EPSRC grant (EP/S033394/1) in 2019, to replace the old technology instrument instrument dating from 2005 with a new core instrument to be delivered 2Q2021.
Publications by Prof Gai and Prof Boyes and their coworkers in internationally leading scientific journals, include, The Accounts of Chemical Research (2020) of the American Chemical Society (ACS), ACS Catalysis (2018), Journal of Physical Chemistry (2019), which are in addition to Journal of the America Chemical Society (JACS), and Chemistry of Materials. Invited talks have been presented at the Royal Society on in-situ microscopy. In addition to the development of the ESTEM instrumentation, Professor Dame Pratibha Gai, FREng, FRS, Prof Ed Boyes and their colleagues have edited a special issue of Philosophical Transactions of the Royal Society (A) on in-situ microscopy relating structure and function. published in December 2020. Invited talks have been presented on in-situ electron microscopy.
This special issue contains a collection of presentations from our earlier organisation and chair of an international discussion meeting held at the Royal Society, London, in October 2019. Gai PL, Boyes ED, Brydson R, Catlow R. 2020
Dynamic in situ microscopy relating structure and function. Phil. Trans. R. Soc. A 378: 20190596.
http://dx.doi.org/10.1098/rsta.2019.0596
New materials and new ways of using old ones form the foundation of our physical world by providing new properties, capabilities and opportunities for value generation to address societal needs for products and services. Properties depend on bespoke and sometimes serendipitous selection and arrangement of atoms and interactions. It is increasingly recognized that materials are often in transition and mechanisms of change create the properties we experience. Dynamic in situ microscopy methods relating structure and function allow exploration and rational control of this fascinating aspect of the world, from the fundamental scale of atoms up to real world applications. The benefits to science and technology include new knowledge leading to improved processes across a diversity of materials applications, reductions in energy requirements and better management of environmental considerations.
Publications of Professors Gai, Boyes and their team are in internationally leading scientific journals, including, Philosophical transactions of the Royal Society (A), Accounts of Chemical Research of the American Chemical Society. They are as following.

Martin TE, Mitchell RW, Boyes ED, Gai PL. 2020
Atom-by-atom analysis of sintering dynamics and stability of Pt nanoparticle catalysts in chemical reactions.
Phil. Trans. R. Soc. A 378, 20190597.
(doi:10.1098/rsta.2019.0597)
Supported Pt nanoparticles are used extensively in chemical processes, including for fuel cells, fuels, pollution control and hydrogenation reactions. Atomic-level deactivation mechanisms play a critical role in the loss of performance. In this original research paper, we introduce real-time in-situ visualization and quantitative analysis of dynamic atom-by-atom sintering and stability of model Pt nanoparticles on a carbon support, under controlled chemical reaction conditions of temperature and continuously flowing gas. We use a novel environmental scanning transmission electron microscope with single-atom resolution, to understand the mechanisms. Our results track the areal density of dynamic single atoms on the support between nanoparticles and attached to them; both as migrating species in performance degradation and as potential new independent active species. We demonstrate that the decay of smaller nanoparticles is initiated by a local lack of single atoms; while a post decay increase in single-atom density suggests anchoring sites on the substrate before aggregation to larger particles. The analyses reveal a relationship between the density and mobility of single atoms, particle sizes and their nature in the immediate neighbourhood. The results are combined with practical catalysts important in technological processes. The findings illustrate the complex nature of sintering and deactivation. They are used to generate new fundamental insights into nanoparticle sintering dynamics at the single-atom level, important in the development of efficient supported nanoparticle systems for improved chemical processes and novel single-atom catalysis.This article is part of a discussion meeting issue 'Dynamic in situ microscopy relating structure and function'.
Electronic supplementary material is available online at https://doi.org/10.6084/m9.figshare.c.5095254

Boyes ED, LaGrow AP, Ward MR, Martin TE, Gai PL. 2020
Visualizing single atom dynamics in heterogeneous catalysis using analytical in situ environmental scanning transmission electron microscopy.
Phil. Trans. R. Soc. A 378, 20190605.
http://dx.doi.org/10.1098/rsta.2019.0605

Progress is reported in analytical in situ environmental scanning transmission electron microscopy (ESTEM) for visualizing and analysing in real-time dynamic gas-solid catalyst reactions at the single-atom level under controlled reaction conditions of gas environment and temperature. The recent development of the ESTEM advances the capability of the established ETEM with the detection of fundamental single atoms, and the associated atomic structure of selected solid-state heterogeneous catalysts, in catalytic reactions in their working state. The new data provide improved understanding of dynamic atomic processes and reaction mechanisms, in activity and deactivation, at the fundamental level; and in the chemistry underpinning important technological processes. The benefits of atomic resolution-E(S)TEM to science and technology include new knowledge leading to improved technological processes, reductions in energy requirements and better management of environmental waste.
This article is contribution to a discussion meeting issue 'Dynamic in situ microscopy relating structure and function'.
Boyes ED, LaGrow AP, Ward MR, Mitchell RW, Gai PL. 2020 Single atom dynamics in chemical reactions.
Acc. Chem Res. 53, 390-399, 2020.
https://doi.org/10.1021/acs.accounts.9b00500

Many heterogeneous chemical reactions involve gases catalyzed over solid surfaces at elevated temperatures and play a critical role in the production of energy, healthcare, pollution control, industrial products, and food. These catalytic reactions take place at the atomic level, with active structures forming under reaction conditions. A fundamental understanding of catalysis at the single atom resolution is therefore a major advance in a rational framework upon which future catalytic processes can be built. Visualization and analysis of gas-catalyst chemical reactions at the atomic level under controlled reaction conditions are key to understanding the catalyst structural evolution and atomic scale reaction mechanisms crucial to the performance and the development of improved catalysts and chemical processes. Increasingly, dynamic single atoms and atom clusters are believed to lead to enhanced catalyst performance, but despite considerable efforts, reaction mechanisms at the single atom level under reaction conditions of gas and temperature are not well understood. The development of the atomic lattice resolution environmental transmission electron microscope (ETEM) by the authors is widely used to visualize gas-solid catalyst reactions at this atomic level. It has recently been advanced to the environmental scanning TEM (ESTEM) with single atom resolution and full analytical capabilities. The ESTEM employs high-angle annular dark-field imaging where intensity is approximately proportional to the square of the atomic number (Z). In this Account, we highlight the ESTEM development also introduced by the authors for real time in situ studies to reliably discern metal atoms on lighter supports in gas and high temperature environments, evolving oxide/metal interfaces, and atomic level reaction mechanisms in heterogeneous catalysts more generally and informatively, with utilizing the wider body of literature. The highlights include platinum/carbon systems of interest in fuel cells to meet energy demands and reduce environmental pollution, in reduction/oxidation (redox) mechanisms of copper and nickel nanoparticles extensively employed in catalysis, electronics, and sensors, and in the activation of supported cobalt catalysts in Fischer-Tropsch (FT) synthesis to produce fuels. By following the dynamic reduction process at operating temperature, we investigate Pt atom migrations from irregular nanoparticles in a carbon supported platinum catalyst and the resulting faceting. We outline the factors that govern the mechanism involved, with the discovery of single atom interactions which indicate that a primary role of the nanoparticles is to act as reservoirs of low coordination atoms and clusters. This has important implications in supported nanoparticle catalysis and nanoparticle science. In copper and nickel systems, we track the oxidation front at the atomic level as it proceeds across a nanoparticle, by directly monitoring Z-contrast changes with time and temperature. Regeneration of deactivated catalysts is key to prolong catalyst life. We discuss and review analyses of dynamic redox cycles for the redispersion of nickel nanoparticles with single atom resolution. In the FT process, pretreatment of practical cobalt/silica catalysts reveals higher low-coordination Co0 active sites for CO adsorption. Collectively, the ESTEM findings generate structural insights into catalyst dynamics important in the development of efficient catalysts and processes.
Michael R. Ward, Robert W. Mitchell, Edward D. Boyes, Pratibha L. Gai. Visualization of atomic scale reaction dynamics of supported nanocatalysts during oxidation and ammonia synthesis using in-situ environmental (scanning) transmission electron microscopy. Journal of Energy Chemistry 2021, 57 , 281-290. https://doi.org/10.1016/j.jechem.2020.08.069
Exploitation Route PhD students and postdoctoral research fellows, visiting researchers from both the UK and international institutions,, UK industrial collaborations, including with Johnson Matthey. Collaborative research with Johnson Matthey has resulted in an important publication in ACS Catalysis of the American Chemical Society.
Sectors Chemicals,Energy,Environment

 
Description The AC ESTEM instrumentation project involved design, construction, creation and development of an analytical tool with single atom resolution under reaction conditions by Professor Boyes and Professor Gai, Principal Investigators of the project and the ESTEM intsrument is unique in the world. In addition to creating the massive instrumentation, early applications of the successfully completed new system have been undertaken by Boyes and Gai group. This development is arguably the main outcome of the programme which has now ended. Clearly a follow-on grant by EPSRC will be necessary for pursuing the work further in the UK and exploit the original work for the benefit of the UK. Based on our work University of York is now partner of EPSRC's SuperSTEM in Daresbury. (It may be noted that if a follow-on grant to exploit the novel ESTEM instrumentation we have developed is not available, we expect similar developments to be taken up by UK competitors and all of it is likely to be outside the UK). Our previous project (carried out outside the UK) has generated more than £100,000,000, with at least as much again in application results). Our ESTEM work has also greatly impacted other non-academic institutions. Johnson Matthey PLC have contributed two CASE studentships at a total cost to them with custom synthesised materials, chemical testing, management time and other add-ons, of about £70,000 and have engaged closely with the programme, culminating in a paper to be presented at their annual academic conference this year (April, 2018). In addition there has been almost £25,000 of directly paid work for JM outside of these arrangements and contributions to their decision to purchase their own multi-million pound analytical facilities of this general type. The numerous scientific papers continuing to come out are a major way in which the findings are continuing to impact the whole technology enterprise, well beyond the academic community. As the new knowledge and principles are disseminated we expect to see in-direct benefit in process understanding and control improvement by developing the science underpinning technology applications of societal benefit. We now have only a small share of a University 20% FTE commitment (awarded FRS, 2016 and DBE, 2018 for the work) and a final writing up student to continue the work and its exploitation. Both Professor Dame Pratibha Gai and Prof Edward Boyes have been elected Fellows of the Microscopy Society of America in 2019. Our work has impacted non-academic Johnson Matthey (JM) PLC catalysis division. The division has benefitted from our research in Fischer-Tropsch (FT) catalysis. The work has led to fundamental understanding of precursor transformation to active catalysts crucial to heterogeneous FT catalysis directed towards production of hydrocarbons for transportation fuels. In FT catalysis, the effect of pre-treatment over supported cobalt catalysts, the catalyst dispersion, the dynamic atomic structure and the activity of the catalysts was not fully understood. Our systematic studies into the formation of active catalyst phases in supported Co catalyst precursors on various ceramic oxide supports (such as silica, alumina, titania and zirconia) in FT catalysis using novel in-situ environmental (scanning) transmission electron microscopy (E(S)TEM) with single atom resolution under controlled reaction environments in real time, coupled with other methods have revealed findings for better dispersion leading to a larger number of low-coordination Co0 sites and a higher number of active sites for the catalysis and have helped to generate new structural insights into the catalyst dynamics important to the development of efficient FT catalysts. Research has also been carried out with the Technology Centre of Johnson Matthey on low cost catalysts for ammonia synthesis. In Fuel cell technology division of Johnson Matthey our research has also impacted fuel cell research. Fuel cell technology can provide an alternative to fossil fuel combustion engines for powering automobiles. The development of a cost effective oxygen reduction catalyst is perceived as one of the main enablers of a more widespread adoption of the technology. Although costly platinum nanoparticles are the standard for the current fuel cell catalysts, practical bimetallic platinum based nanoparticles such as platinum-cobalt are of considerable interest for economical fuel cell catalysts. Our novel ESTEM development with single atom resolution under reaction conditions has provided new atomic level insights into practical bimetallic fuel cell catalyst structures under reactive gas and temperature environments and their function. Our studies have examined the origin of the evolution of nanostructures and the formation of the fuel cell nanocatalysts and have revealed the dynamic transformation of practical Pt-Co precursors, in particular how cobalt and platinum initially mix to form a range of structures leading to complex practical catalysts for fuel cell applications. The work has led to new knowledge of how platinum and cobalt precursors interact with each other at the atomic level during the reduction in flowing hydrogen at 200, 450 and 700 °C under controlled conditions inside the ESTEM. The insights have enabled the understanding of precursor transformation and the possible nanoparticle alloy formation in fuel cell catalysts as they take place important to optimise catalyst compositions. The new researches have been detailed in our recent publication Accounts in Chem.Res. vol 53, p.390 (2020).Based on the novel in-situ ESTEM instrument development work of Boyes and Gai, the York Nanocentre at the University of York has been successful with an EPSRC grant (EP/S033394/1) in 2019, to replace the old technology instrument instrument dating from 2005 with a new core instrument to be delivered 2Q2021. Other researches include materials analyses for UK nuclear industries in collaboration with the University of Leeds. Redispersion of nickel nanoparticles has been explored using our novel development of E(S)TEM (published in Chemistry of Materials, vol 30, p.197, (2018). Effects of pre-treatment of Fischer-Tropsch catalysts towards fuel production have been investigated (published in ACS Catalysis, vol 8, p 8816, 2018). This research has been carried out with UK Chemical industry, namel,y Johnson Matthey.
First Year Of Impact 2014
Sector Chemicals,Energy,Environment,Healthcare,Transport
Impact Types Societal

 
Description Membership of working party on advanced electron microscopy in the UK
Geographic Reach National 
Policy Influence Type Participation in a advisory committee
Impact Guidelines for future sustainable investment in the field of reserach
 
Description SuperStem
Geographic Reach National 
Policy Influence Type Influenced training of practitioners or researchers
 
Description CASE studentship
Amount £90,000 (GBP)
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 11/2014 
End 10/2018
 
Description Case Studentship
Amount £90,000 (GBP)
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 10/2012 
End 09/2015
 
Title AC ESTEM 
Description Development and Applications of Aberration Corrected Environmental STEM (AC ESTEM) for Dynamic In-Situ Reaction Studies of Nanoparticle Catalysts EP/J018058/1 Professor Pratibha L Gai and Professor Edward D Boyes, University of York With the award of the EPSRC grant we have developed the world's first full function high performance aberration corrected environmental scanning transmission electron microscope (AC ESTEM). It has <0.1nm resolution capability and single atom sensitivity for dynamic in-situ experiments on solid state heterogeneous catalysts for gas reaction studies and we are now moving into the application intensive phase of the project. Our development has created in the UK a novel and globally leading research capability providing Angstrom Analysis for dynamic in-situ reaction studies under controlled conditions of temperature and continuous gas atmosphere; rather than the usual high vacuum or pulsed gas. We have modified an existing AC TEM/STEM instrument to complement and extend its capabilities with gas reaction studies while maintaining, and in some aspects extending, vacuum especially, the full performance and functionality of the core tool. Our new design provides the world's first full function aberration corrected environmental scanning transmission electron microscope (AC ESTEM). The global competition (approx. 20 labs, all overseas - Europe, USA, Japan) continues to use a version of our earlier ETEM design which is in practice high resolution in TEM only and come with a single aberration corrector for TEM imaging. The old design has significant analytical and imaging limitations which make it unsuitable for multi-user environments; to the extent several laboratories have a dedicated machine (as we did with the original) and second instrument for other uses. This is expensive in both capital and operating costs as well as in real estate and support needs. With the modifications to the machine at York, ETEM is also (re-) introduced into the UK in high resolution form. Perhaps more significantly, cost-wise, the full ESTEM functionality also supports full STEM for the parallel high vacuum operations. This in itself is major advantage of the new developments which not only enable the new functionalities but also support a much wider and more intensive utilisation of the core capital kit investment in multi-use applications, as well as ensuring the substantially fixed support coats are spread over as wide a range of applications as possible. In association with partners in the vibrant UK chemical and energy industries we are generating fundamental application science underpinning nanoparticle based solid state heterogeneous catalysis used in gas-solid reactions. Our primary industry partners are Johnson Matthey Plc. With the award of the grant in 2012 we began construction of modifications beyond the very limited initial proof-of-principle demonstrations for gas operations on the multi-use high resolution microscope in our laboratory at York. This included a complete rebuild of the column pumping systems and replacement of the supplied pipework with new designed for purpose stainless steel pipework and fittings to full UHV standards of cleanliness. As planned, this proved to be an economical route to go; in part due to the standardisation of parts in a competitive market and because the UK retains an industry able quickly to make special pipework, also at modest cost. The year 2013 saw the launch of our aberration corrected ESTEM as a scientifically useful capability. Further improvements to the new core capability and to support other uses of the capital kit with a minimum of compromises and crucially without the need to change the machine configuration for different applications, are continuing. For example there is a simple and rapid switch over from gas-mode to high vacuum mode with no changes to the hardware involved. For the first time we have designed and built a machine in which the gas introduction, pumping and control systems do not interfere with the conventional high vacuum performance and in some respect improve on it. Phase one technical developments on the microscope have been successfully completed and they have produced a first high profile application publication in Annalen der Physik in June 2013. With the developments we have made we have created at minimal expense world leading new ESTEM functionality without compromising other attributes for these and other applications on the existing high vacuum multi-user machine. Recent progress with the new generation of MEMS hot stages we have been able to purchase with the grant (substituting for part of the originally proposed old technology), has been transformational in what we can do scientifically, in productivity and with most of the technical support by ourselves on site rather than regular sagas of return- to-foreign-factory for service. This development makes it practical to track areas continuously over time and during temperature transits, with especial relevance to comparison data for the MC calculations; themselves not part of the project but augmenting it through studentships. The science the new capabilities open up is exciting. It provides a key tool for the study of single atoms in catalysts under reaction conditions in a machine also able to analyse the structure of the nanoparticles. This is a novel and potentially very important development in terms of impact. As well as new information on the migration of materials from one discrete, in this case metal, nanoparticle to another; it shows the potential importance of these species as active sites themselves; out there on the support surface. This work relates to parallel on-going Monte Carlo calculations and provides important input for further calculations of functionality and specific chemical reactivity; through for example the DFT methods we used for catalytic nanoparticles (at that time studied without gas) in a 2012 Nanoletters paper. In 2014 further technical developments on the microscope have increased the gas pressures inside the microscope (as outlined in our EPSRC grant proposal) and resulted in high profile publications in the first quarter of 2014, including in Comptes Rendu (Physique). This is also the time for ramping up the PDRA supported applications of the new kit developments. 3x PDRAs have now been appointed; all of them experienced electron microscopists with application domain science backgrounds in nanoparticle physics and chemistry for cstalysis. In this we have been most fortunate. Support for continuing as associate partner of EPSRC SuperSTEM at Daresbury, as the in-situ component of the EPSRC National facility for aberration corrected electron microscopy. Project work with Leeds and Sheffield on this. There has been significant industrial collaboration leading to joint publications with Johnson Matthey Plc, a FTSE 100 company and world leader in precious metals and catalysis. JM was also a strong supporter of our grant proposal and the interaction continues to be further strengthened at the strategic and tactical levels. The latter include CASE studentships, access to their extensive technical resources for both specimen preparation (including custom preparation to our specifications where needed) and testing, and regular direct technical work for which they pay the University. Ph.D. CASE awards: 2 EPSRC PhD CASE award studentships with Johnson Matthey and BP EPSRC postdocs: 3 EPSRC postdoctoral fellows (4x PDRA posts : 3 now filled) supported by the grant. There is also 50% support for our excellent Experimental Officer.. 
Type Of Material Improvements to research infrastructure 
Year Produced 2013 
Provided To Others? Yes  
Impact Imaging of single atoms on supports between nanoparticles in heterogeneous solid state catalysts in gas reaction studies of catalyst activation, operation and deactivation under controlled conditions of specimen temperature and gas environment has been introduced (to the world) using the aberration corrected environmental scanning transmission electron microscope developed under this project. These have previously been thought of primarily as species migrating between the larger nanoparticles on the surfaces of which they are catalytically active. However, the new studies they have a life of their own while in transit and during this phase they are likely to have different and potentially more active properties. The work has resulted in a number of publications and prestigious presentations, as set out in that part of this report, e.g Annalen der Physik (2013) 
 
Title AC ESTEM development 
Description Environmental STEM (AC ESTEM) for Dynamic In-Situ Reaction Studies of Nanoparticle Catalysts (EP/J018058/1) by Professor Edward D Boyes (CoI) and Professor Pratibha L Gai (PI), University of York In chemical technology heterogeneous catalysts consisting of nano-scale particles operate in gas atmospheres and at elevated temperatures. Cutting edge fundamental science is needed to understand and improve performance of the behaviour of these catalysts in controlled reaction environments, to support internationally competitive chemical process industries in the UK. As part of our EPSRC grant EP/ EP/J018058/1 we have developed, for the first time globally, aberration corrected environmental scanning transmission electron microscopy (AC ESTEM) instrumentation. This project has established in the UK the world's first atomic resolution (AC) E(S)TEM capability and we are making it increasingly widely available to colleagues in the UK and in collaborations internationally. The AC ESTEM capabilities include, atomic scale imaging and analysis under controlled conditions of gas environment around the specimen held at high temperature. The new facilities operate under a sub set of realistic reaction conditions with single atom sensitivity. Include are Z-contrast high angle annular dark field (HAADF) STEM imaging, energy dispersive x-ray chemical analysis and wide angle electron diffraction (including CBDP), as well as electron energy loss spectroscopy (EELS). The project is designed to generate for the first time and in close collaboration with the vibrant UK catalysis and chemicals industry, fundamental and practical atomic scale understanding of key preparative, activation, reaction, deactivation and where practical reactivation processes. Analysis of real world practices show considerable scope for improvement in deploying resources, including the amount of precious metals needed for automotive exhaust emissions controls. Details : Development of novel AC E(S)TEM : We have modified an existing AC TEM/STEM instrument to complement and extend its capabilities with gas reaction studies while maintaining, and in some aspects extending the full performance and functionality of the core tool. Our new design provides the world's first full function aberration corrected environmental scanning transmission electron microscope (AC ESTEM). The global competition (approx. 20 labs, all overseas -including Europe, USA, Japan) continues to use a version of our earlier ETEM design which is in practice high resolution in TEM only and come with a single aberration corrector for TEM imaging. The old design has significant analytical and imaging limitations which make it unsuitable for multi-user environments; to the extent several laboratories have a dedicated machine (as we did with the original) and second instrument for other uses. This is expensive in both capital and operating costs as well as in real estate and support needs. With the modifications to the machine at York, ETEM is also (re-) introduced into the UK in high resolution form. Perhaps more significantly, cost-wise, the full ESTEM functionality also supports full STEM for the parallel high vacuum operations. This in itself is major advantage of the new developments which not only enable the new functionalities but also support a much wider and more intensive utilisation of the capital kit investment in multi-use applications, as well as ensuring the support coats are spread over as wide a range of applications as possible. In association with partners in the vibrant UK chemical and energy industries we are generating fundamental application science underpinning nanoparticle based solid state heterogeneous catalysis used in gas-solid reactions. Our primary industry partners are Johnson Matthey Plc. With the award of the grant in 2012 we began construction of modifications beyond the very limited proof-of-principle demonstrations for gas operations on the multi-use high resolution microscope in our laboratory at York. The year 2013 saw the launch of our aberration corrected ESTEM as a scientifically useful capability. Further improvements to the new core capability and to support other uses of the capital kit, with a minimum of compromises and crucially without the need to change the machine configuration for different applications, are continuing. For example there is a simple and rapid switch over from gas-mode to high vacuum mode. Phase one technical developments on the microscope have been successfully completed and they have produced a first high profile application publication by E D Boyes and P L Gai et al in Annalen der Physik in June 2013. With the developments we have created a world leading new ESTEM functionality without compromising other attributes for these and other applications on the existing high vacuum multi-user machine. Recent progress with the new generation of MEMS hot stages we have been able to purchase with the grant (substituting for part of the originally proposed old technology), has been transformational in what we can do scientifically, in productivity and with most of the technical support by ourselves on site rather than regular sagas of return- to-foreign-factory for service. This development makes it practical to track areas continuously over time and during temperature transits, with especial relevance to comparison data for the MC calculations; themselves not part of the project but augmenting it through studentships. The science the new capabilities open up is exciting. AC ESTEM provides a key tool for the study of single atoms in catalysts under reaction conditions with the ability to analyse the structure of the nanoparticles. This is a novel and very important development in terms of impact. As well as new information on the migration of materials from one discrete, in this case metal, nanoparticle to another; it shows the importance of these species leading to active sites. This work relates to parallel on-going Monte Carlo (MC) calculations and provides important input for further calculations of functionality and specific chemical reactivity; through for example the density functional theory (DFT) methods we used for catalytic nanoparticles (at that time studied with temperature and without gas) in our 2012 Nanoletters paper (vol. 12, p.2027). In 2014 further technical developments on the microscope have increased the gas pressures inside the microscope (as outlined in our EPSRC grant proposal) and resulted in high profile publications in the first quarter of 2014, including in Comptes Rendu Phys. by E D Boyes and P L Gai (15, p.200, 2014) and MRS Bull. 40, 600 (2015). This has also been the time for ramping up the PDRA supported applications of the new kit developments. 4x PDRAs have now been appointed; all of them experienced electron microscopists with application domain science backgrounds in nanoparticle physics and chemistry for catalysis. In this we have been most fortunate. Our AC ESTEM development has led to the support for continuing as associate partner of EPSRC SuperSTEM at Daresbury, as the in-situ component of the EPSRC National facility for aberration corrected electron microscopy. Project work with Leeds and Sheffield are ongoing on this. There has been significant industrial collaboration leading to joint publications with Johnson Matthey Plc, a FTSE 100 company and world leader in precious metals and catalysis. JM was also a strong supporter of our grant proposal and the interaction continues to be further strengthened at the strategic and tactical levels. The latter include CASE studentships, access to their extensive technical resources for both specimen preparation (including custom preparation to our specifications where needed) and testing, and regular direct technical work for which they pay the University. Ph.D. CASE awards: 2 EPSRC PhD CASE award studentships with Johnson Matthey and BP EPSRC postdocs: 4 EPSRC postdoctoral fellows (4x PDRA posts : now filled) supported by the grant, namely, Drs. M R Ward, R W Mitchell, A La Grow and Gnanavel Thirunavukkarasu. There is also 50% support for our Experimental Officer,Dr. L. Lari. 
Type Of Material Improvements to research infrastructure 
Year Produced 2013 
Provided To Others? Yes  
Impact The grant holders- Professors Gai and Boyes' track record as world leaders in this field has been recognised by the award of the biannual Institute of Physics Gabor medal and prize in September 2010, Fellowship of the Institute of Physics (EDB); L'Oreal-UNESCO Women in Science award as the 2013 Laureate for Europe (PLG); the Fellowship of the Royal Academy of Engineering (PLG); and the EPSRC sponsored committee membership on the future of advanced electron microscopy in the UK (EDB). The grant holders- Professors Gai and Boyes' track record as world leaders in this field has been recognised by the award of the biannual Institute of Physics Gabor medal and prize in September 2010, Fellowship of the Institute of Physics (EDB); L'Oreal-UNESCO Women in Science award as the 2013 Laureate for Europe (PLG); the Fellowship of the Royal Academy of Engineering (PLG); and the EPSRC sponsored committee membership on the future of advanced electron microscopy in the UK (EDB). The work has led to the establishment in the UK of the leading centre globally for high resolution dynamic in-situ reaction and other phase transformation studies under controlled conditions of gas atmosphere and temperature. With this project we have introduced the first environmental scanning transmission electron microscope (ESTEM) instrumentation with 0.1nm resolution and single atom sensitivity for dynamic in-situ experiments on heterogeneous catalysts under controlled conditions of gas atmosphere and of high temperatures. Significant parts of the chemical and energy industries, in which the UK is internationally competitive, depend on heterogeneous catalysis based on active nanoparticles, often of metal, dispersed on a support which is typically carbon or ceramic oxide supports. Small particles in the low nanometre range have size dependent properties; sometimes of character and always of surface area for a given volume. There is always a battle between initial effectiveness, measured in activity and selectivity, and structural and chemical stability; in the process unfortunately but correctly defying the textbook definition of a catalyst as unchanging. Electron microscopy is a leading method of studying such materials, and the authors (PI and CoI) of this project have led its adaptation globally for purpose over three decades. The principle development has been to create differentially pumped instrumentation in which dynamic in-situ reaction study experiments can be performed with atomic resolution under controlled conditions of temperature and most importantly of gas atmosphere; replacing the usual, and chemically alien, high vacuum atomic resolution analytical instrument environment. These developments allow chemically active species to be created and studied in-situ, rather than optimistically required to be transferred into the analytical system through air without modification. Details of their development or activation, subsequent operation and eventual deactivation, and even reactivation and precious metals recovery, can be followed through dynamic sequences in ESTEM. This allows much more reliable and insightful experiments than would otherwise be possible, and indeed some prior art studies have had to be substantially revised on this basis; for example by clearly separating (and correcting) reaction causes and effects. We have now made further significant advances in the method with a radical new approach to system engineering. Most importantly this allows, we believe for the first time, full integration with a double aberration corrected TEM/STEM instrument at 0.1nm resolution in both modes. This enables the first high performance E(S)TEM (environmental (scanning) transmission electron microscopy) in the world. A major advance with the new approach has been to enable full use of the atomic resolution and atomic number (Z) contrast high angle annular dark field (HAADF) with single atom sensitivity, which is key to understanding reaction mechanisms. This is not possible with the previous designs being used around the world which are configured primarily for high resolution TEM, rather than STEM imaging. Most such systems used globally are copies of earlier designs of atomic resolution-ETEM pioneered by Boyes and Gai; most cogently described in references [E D Boyes and P L Gai, Ultramicroscopy, 92, 67 (1997); P L Gai, E D Boyes, et al. MRS Bulletin 32(no.12): 1044 (2007) and P L Gai et al Science, 67, p.661]. We are therefore well aware of the strengths - and weaknesses - of these systems in which global investment now amounts to many 10s of millions of £, including in continental Europe, Japan and the US. To date there have been no high performance ETEMs in the UK where the situation is a regression from where the authors left it in the late 1980s. Since then the steady expansion and recent explosion in ETEM activities has been exclusively overseas. An incidental impact, but one of some considerable significance, is likely to be a cohort of younger researchers exposed to the 'can-do' spirit that it is very desirable, and indeed doable, to reconfigure even sophisticated apparatus for specific significant purpose, and in the process gain a personal and institutional competitive advantage. As in the current project, this approach, done right, can substantially extend the productive life of core capital kit by adapting it for specific purpose. All useful learnings from the project. With the new configuration, parallel high performance chemical analysis by energy dispersive x-ray spectrometry (EDX) is also made possible for the first time in an E(S)TEM. This is additionally important since the modus operandi, in part for reliability and in part to optimise capital investment in multiple application domain sciences, is to leave the E(S)TEM components permanently mounted in the column and to operate interchangeably with and without a gas environment for experiments with different needs. EDX is an important complement to any high resolution STEM study and its inclusion on the new machine is therefore especially important; in addition to introducing its direct use in chemical experiments including dynamic in-situ catalysis studies. The restriction on gas pressures to <0.1 torr this entails is still well within the 'high' pressure (>0.001 torr) region of surface studies, as defined in the literature [PCCP 9, 3500-3513, (2007)], although of course much less than used in some commercial reactors. The connection is through the science. The new activities are becoming a magnet for broad scientific interest to generate an impressive showpiece for British science both through its output and its physical presence. In addition to our novel instrumental development, this project is focused on new methods of fundamental science applied to technology applications in collaboration with leading UK companies, whose expertise, interests and needs are contributing significantly to the planning, implementation, development and exploitation of the novel AC E(S)TEM development. Other areas of impact of this project include: • training of a cohort of students, PDRAs, visiting scientists and academic colleagues • the establishment in the UK the global centre of excellence in this aspect of in-situ catalysis science and of the experimental methods on which it is based • the extension of the science base on the structure and stability of the smaller sizes, generally <10nm, of nanoparticles on various supports of practical significance • the AC E(S)TEM development is playing a key role in understanding atomic reaction mechanisms in the following York programmes in collaboration with the UK chemical industry. Examples include: (a) AC ESTEM imaging of single atoms under controlled temperature and gas environment conditions in catalyst reaction studies. (Ann.Phys. (Berlin) 525, 423 (2013). and Chemical Physics Letters (592, 355, 2014); (b) Understanding atomic scale interactions in electrode catalysts for fuel cells in reduction and oxidation environments using AC E(S)TEM: (c) Visualisation and analysis of single atom dynamics in water gas shift (WGS) reaction (CO+H2O? CO2+H2) for hydrogen generation important to fuel cells using AC E(S)TEM. Here the in-situ atomic resolution observations on practical gold/ceria catalysts have revealed the formation of clusters of a few gold atoms from single atom dynamics under controlled WGS environments at operating temperatures influencing the WGS catalysis(Catal Sc. Tech.2015; DOI: 10.1039/c5cy01154j; in collaboration with Johnson Matthey). Direct technological applications of the science in industrial catalysis practice with economic and profit advantages for industrial practitioners better informed by project results. -These include identification of key nanostructures and their composition in the function and deactivation of diesel oxidation catalysts (DOC) employed for auto-exhaust emission control. (in collaboration with Johnson Matthey Plc, published in ChemCatChem (Ward et al: 5, 2655, 2013)). Individual particle sintering in copper based systems of interest in methanol synthesis (EPSEC CASE Award with BP); published in ChemCatChem (Martin et al: 2015)); Discovery of reaction mechanism in the CO oxidation on inherently strained gold nanoparticles (Nanoletters,12, 2027, 2012 Johnson Matthey plc CASE/EPSRC award) (c) Oxidation kinetics in Ni based systems of interest in catalytic hydrogenation reactions using AC E(S)TEM: in collaboration with Johnson Matthey Technology Centre, (CASE award); • environment and energy advantages of more efficient processes minimising waste and pollution • new instrument developments with potential IP returns to the project • strengthening direct support and collaborations with major UK based industrial partners: lead sponsors are Johnson Matthey and BP. • directly chargeable services to industry more widely with a preferential confidential IP strategy • enhanced UK competitiveness in the catalysis business, both from directly applicable results and from a strengthened knowledge base; and the widely disseminated awareness of the existence of this as an important sponsor marketing tool • further support for the on-going collaborations with Nagoya University, with staff and student exchanges supported by the Japanese Society for the Promotion of Science (JSPS), and also with IISc Bangalore and Cadiz University. • new academic collaborations: in the UK, Europe and more widely to access the exciting new capability • enhancing the reputation of the University and more broadly of British science, and of its wise sponsors, by raising the profile of activities (Please see awards section with significant awards and invited keynote lectures at leading conferences and journals internationally: including, Materials Research Society (MRS), Microscopy Society of America and international microscopy Congress; along with featured highlights in the American Chemical Society Chemical & Engineering News; MRS Bulletin and the Royal Society of Chemistry). - and building national, international and industrial networks of collaboration and exploitation. 
 
Title Development and Applications of Aberration Corrected Environmental STEM (AC ESTEM) for Dynamic In-Situ Reaction Studies of Nanoparticle Catalysts 
Description Heterogeneous gas-solid catalyst reactions are widely used in chemical process technologies in the UK chemical industry. The gas-catalyst reactions take place at the atomic level. World leading fundamental science of the gas-catalyst reactions at the atomic level under controlled reaction environments is therefore needed to understand and develop improved catalysts and processes to support internationally competitive chemical process industries in the UK. The importance of heterogeneous catalysis is recognised in EPSRC research theme roadmaps (as one of the relatively few established areas of science continuing to be selected to GROW) and the field supports the very competitive catalysis industry in the UK. As part of our very successful EPSRC grant EP/ EP/J018058/1 we (the PI and CoI (Professor Gai and Professor Boyes) have invented, designed, constructed the world's first aberration corrected environmental scanning transmission electron microscopy (AC ESTEM) instrumentation at Yok. This project has established in the UK the world's first atomic resolution (AC) E(S)TEM capability. The main goals as well as some useful key extensions of our ambitious project have been fully accomplished on the planned timescale and resource base to create a new world leading facility and use it to enable important new science highly pertinent to the science behind heterogeneous catalysis based on metal nanoparticles. The ground-breaking AC ESTEM capabilities include, atomic scale imaging and analysis under controlled realistic reaction conditions of gas environment around the specimen held at high temperature with single atom sensitivity, energy dispersive x-ray chemical analysis and wide angle electron diffraction (including CBDP), as well as electron energy loss spectroscopy (EELS). We are exploiting the catalyst science relevant to the UK industry, instrumentation and methods using the ESTEM [3-8, 10-12, 14,15]. The project is designed to generate for the first time and in close collaboration with the UK catalysis and chemicals industry, fundamental and practical atomic scale understanding of key preparative, activation, reaction, deactivation and where practical reactivation processes. Analysis of real world practices show considerable scope for improvement in deploying resources, including the amount of precious metals needed for automotive exhaust emissions controls. We are also making our ESTEM development available to colleagues in the UK academia and in collaborations internationally. The modern era in the field started with the development of the atomic resolution, TEM only, gas-in-microscope ETEM (Environmental Transmission Electron Microscope, ETEM), introduced by Boyes and Gai in the USA in the 1990s [1, 2]. The model is now widely used in commercial form (FEI) at a unit cost of ~£5M; with ~20x based on our work, further instruments being acquired and >100 high impact publications now resulting. There are dedicated units in Asia, USA and Europe, in academia and industry, but currently there are none in the UK and our ESTEM development is the first such instrument in the UK. (Described in the Details section below). (In Manchester, Johnson Matthey/Harwell) there are two limited commercial gas specimen holder systems, based on the work of Cremer [16a] and Bigelow [16b,19], but with limited gas-handing and analytical capabilities). Under the EPSRC ESTEM Catalysis grant, EP/J018058/1 we have constructed and have begun to apply key technical developments on the core aberration corrected JEOL 2200 STEM (+TEM) electron microscope. For the first time globally using an electron microscope, catalysts can be analysed with sub-Ångstrom resolution and reliable single atom sensitivity under a selected sub-set of controlled chemical reaction conditions [3-6]. Continuous gas exposure floods the catalyst with reactants at elevated temperature under dynamic real time in-situ reaction conditions. With the just concluded York grant EP/J018058/1 the ETEM has been given a very significant application driven redesign to include for the first time a full set of previously absent but scientifically informative ESTEM imaging and analytical functions. We have made opportunistic custom modifications to a 200KV JEOL 2200FS platform, with Cs aberration correction for both the TEM image and STEM probe, to create the powerful and global pioneer ESTEM (Environmental Scanning Transmission Electron Microscope) with full STEM imaging and analysis. It has been created in-house at modest cost, since the core instrument and specialised site capital investments were already in place, and it operates under controlled working catalyst conditions of high temperature and continuously flowing gas sample environment [3, 4].: Details Development of our novel AC E(S)TEM instrument: With the support of the previous EPSRC grant, EP/J018058/1, and derived from the approach we developed for the original atomic resolution ETEM [1 ,2], we have designed and built in-house in York the world's first aberration corrected environmental scanning transmission electron microscope (AC ESTEM). It is designed to provide ground breaking new capability and new levels of analysis in heterogeneous catalysis; targeted to new developments in catalysis science understanding and practice. It is a powerful new class of instrument with single atom sensitive analyses under controlled continuous gas reaction conditions at high temperatures. To achieve this we have modified an existing AC TEM/STEM instrument to complement and extend its capabilities with gas reaction studies while maintaining, and in some aspects extending the full performance and functionality of the core tool. Our new design provides the world's first full function aberration corrected environmental scanning transmission electron microscope (AC ESTEM). The global competition (approx. 20 labs, all overseas -including Europe, USA, Japan) continues to use a version of our (Boyes and Gai) earlier ETEM design which is in practice high resolution in TEM only and come with a single aberration corrector for TEM imaging. The old design has significant analytical and imaging limitations which make it unsuitable for multi-user environments; to the extent several laboratories have a dedicated machine (as we did with the original) and second instrument for other uses. This is expensive in both capital and operating costs as well as in real estate and support needs. With the modifications to the machine at York, ETEM is also (re-) introduced into the UK in high resolution form. Perhaps more significantly, cost-wise, the full ESTEM functionality also supports full STEM for the parallel high vacuum operations. This in itself is major advantage of the new developments which not only enable the new functionalities but also support a much wider and more intensive utilisation of the capital kit investment in multi-use applications, as well as ensuring the support coats are spread over as wide a range of applications as possible. In association with partners in the vibrant UK chemical and energy industries we are generating fundamental application science underpinning nanoparticle based solid state heterogeneous catalysis used in gas-solid reactions. Our primary industry partners are Johnson Matthey Plc. With the award of the grant in 2012 we began construction of modifications beyond the very limited proof-of-principle demonstrations for gas operations on the multi-use high resolution microscope in our laboratory at York. The year 2013 saw the launch of our aberration corrected ESTEM as a scientifically useful capability. Further improvements to the new core capability and to support other uses of the capital kit, with a minimum of compromises and crucially without the need to change the machine configuration for different applications, are continuing. For example there is a simple and rapid switch over from gas-mode to high vacuum mode. Phase one technical developments on the microscope were successfully completed and they have produced a first high profile application publication by E D Boyes and P L Gai et al in Annalen der Physik in June 2013. With the developments we have created a world leading new ESTEM functionality without compromising other attributes for these and other applications on the existing high vacuum multi-user machine. Recent progress with the new generation of MEMS hot stages we have been able to purchase with the grant (substituting for part of the originally proposed old technology), has been transformational in what we can do scientifically, in productivity and with most of the technical support by ourselves on site rather than regular sagas of return- to-foreign-factory for service. This development makes it practical to track areas continuously over time and during temperature transits, with especial relevance to comparison data for the MC calculations; themselves not part of the project but augmenting it through studentships. Summary of Approach Atom-by-atom analysis of dynamic catalysts in controlled reaction environments The world's first sub-Angstrom atomic resolution Aberration Corrected Environmental Scanning Transmission Electron Microscope (AC ESTEM) has been designed built and applied by Professor Gai and Professor Boyes, very economically based on the existing conventional high vacuum 200kV JEOL 2200 FS instrument with aberration correctors for the TEM image and STEM probe. It probably remains the only combination globally of the ambitious specification of retaining, and in important ways enhancing, the full performance and resolution of the original core instrument and improving aspects of the analysis capability while adding controlled continuous hot stage and gas atmosphere dynamic in-situ chemical reaction facilities at the sample; supported by multiple stages of differential pumping. With the new instrumentation created under the EPSRC grant we have delivered major scientific applications in catalysis science for which we designed the novel AC ESTEM system - see for example the references to this report numbers [4-7;11,12,14,15], with others in preparation for publication. World leading research has been enabled by the also world leading instrument innovations and suitable engineering and support structures. This has probably involved more in-house development of the instrumentation than in any other laboratory outside Japan; and even of most (all?) there too. The reasoning for adopting this approach has been multi-fold: to support innovative competitive advantages for York's research capabilities; to tailor this to specific project needs and for its own sake; to speed up innovation compared to trying to work with manufacturer lead developments and worse for a small team to simply follow in a moneywise costly manufacturer lead programme like everyone else and also inevitably not to be at the head of that queue. A further driver has been to try to make best use of limited resources and in the process follow the only available path for the innovations in capability development and science applications to happen in York and perhaps in the UK at all. Certainly, without massive additional resources. Finally, this approach is built on York strengths, both in the immediate team and institutionally, in the way we can best provide competitive advantage for ourselves, for the science, for the UK and we suggest for the well-directed funding from the EPSRC. The key science application result is currently seen to have been to reveal the continuing presence of a population of single atoms on the support between established more substantial nanoparticles, e.g. of Pt or Cu on carbon, but likely also more generally, at temperature in a gas atmosphere under controlled in-situ dynamic chemical reaction conditions. This is a major result with many implications and directions for further applications. In the AC ESTEM samples of catalytic materials can follow a similar profile to that typical in a full scale chemical reactor with transfer of precursor(s) under air, it's subsequent activation in a continuous in-situ sequence inside the microscope (or it's directly connected antechamber) under the appropriate (often hydrogen) gas atmosphere followed by reaction which over time may lead to some deactivation with potential for amelioration better informed by the intimate new atom-by-atom analysis of the basis of the processes. This contrasts with other approaches involving cycling of samples through air and high vacuum environments or of restricted microscopy functionalities. The project has been structured around a series of strategic strands, extended with tactical sub-strands, based on the novel capabilities at York for environmental scanning transmission electron microscopy (ESTEM) with atomic resolution and sensitivity: • Atomic scale characterisation of real, industry sourced, catalyst materials and processes • Fundamental studies of processes, including revisiting basic models, on the atom-by-atom scale using model samples based on industrial process chemistry and focus issues • Development of infrastructure, instrumentation and methods to enable the research • Promoting collaborations with UK and overseas colleagues to widen impact of the ESTEM development. Additional details of research: We are exploiting in catalyst science relevant to UK industry, instrumentation and methods created under the very successful EPSRC ESTEM Catalysis critical mass grant, EP/J018058/1 now concluding. With this we have invented, designed, constructed and have begun to apply key technical developments on the core aberration corrected JEOL 2200 STEM (+TEM) electron microscope. For the first time globally using an electron microscope, catalysts can be analysed with sub-angstrom resolution and reliable single atom sensitivity under a selected sub-set of controlled chemical reaction conditions [3-6]. Continuous gas exposure floods the catalyst with reactants at elevated temperature under dynamic real time in-situ reaction conditions With the just concluding York grant the ETEM has been given a very significant application driven redesign to include for the first time a full set of previously absent but scientifically informative ESTEM imaging and analytical functions. We have made opportunistic custom modifications to a 200KV JEOL 2200FS platform, with Cs aberration correction for both the TEM image and STEM probe, to create the powerful and global pioneer ESTEM (Environmental Scanning Transmission Electron Microscope) with full STEM imaging and analysis. It has been created in-house at modest cost, by the approach and since the core instrument and specialised site capital investments were already in place, and it operates under controlled working catalyst conditions of high temperature and continuously flowing gas sample environment [3, 4]. Technically the most noteworthy recent development in the field has been the introduction by the authors of this proposal using the new tool for the first reliable detection of the seemingly general continuing presence of single atoms and small clusters on a support between larger nanoparticles in a typical heterogeneous solid state gas reaction catalyst. To date this is best demonstrated by the important, as well as more generally illustrative, Pt-C system [4], and in quantitative exploitation of the method for Cu [7]. Ground breaking quantitative dynamic atom-by-atom analysis for Pt particle coarsening in hydrogenation reactions is being developed. These results, enabled by the novel York ESTEM instrument developments, are the first reliable single atom sensitive STEM or TEM data under representative operating conditions of a continuous gas atmosphere and controlled high temperature. The new results will be used to inform key catalyst activation, operating and deactivation mechanisms at a new level of atom-by-atom analysis of the direct causes influencing Ostwald Ripening deactivation by atom migration between fixed particle centres. They will extend the prior art TEM studies which have been on a much longer (nm) scale of the coarsening consequences for nanoparticle size growth. The new results will be used to guide how processes might be better controlled and bad outcomes moderated. The impact is potentially worth £Bns in monetary and environmental value. It derives from new insights into the creation of novel strategies which might be used to restrain, or control, key negative impact process variables. The results complement and extend STM work [17], which is generally on ideal substrates with a very restricted range of (small) particle sizes and forms, and replaces much less reliable attempts to use ETEM [18] or high vacuum STEM. As pointed out by the authors [11], even reliable detection, and much less measurement, of <2nm size particles (which are most of the mechanistically important ones) on a support, can be difficult to even detect with the usual bright field EM methods, but the sensitivity of high angle annular dark field (HAADF) STEM imaging available in the ESTEM has been extended down to the single atom level under a sub-set of realistic catalyst operating conditions [4]; noting there is no real TEM equivalent of high angle annular dark field (HAADF) STEM. Working with industrial partner Johnson Matthey Plc we have previously shown [11] that in extended (47,000 mile) real world use on the road, and mirrored in in-situ experiments, the mean size of Pt/Pd particles in a diesel oxidation exhaust emission catalyst (DOC) on an alumina-based support increased from 2.5 to 11(±0.2)nm with a corresponding large reduction in surface area available for reaction. There were also changes in structural character with higher and less reactive Pt-Pt surface co-ordination; and Pd surface enrichment in the Pt/Pd system [11]. This is revealed with precision EDX analysis introduced to the ETEM/ESTEM world with the York development. Over time, catalyst efficacy may be reduced by an order of magnitude or more; or to <10% of the starting state. There is of course in this a massive impact opportunity technically, economically and in the environmental consequences of potentially needing to use much less rare Pt if the new learnings could be used to maintain more nanoparticle surface area, and thereby application catalyst efficiency; either directly or in new opportunities made possible if deactivation processes can at least be made slower; and ideally of course stabilised completely. The newly discovered 'intermediate' species of disordered rafts and clusters down to the single atom level may have different and in some cases more useful reactivity to similar atoms bound on to more established (1-2nm in size and up) fully developed 'bulk-like' crystalline nanoparticles [3,7]. The isolated atoms and surface excrescences, or similar residuals, may be a small fraction of the whole, but they can be expected to have a disproportionately strong effect by being continuously exposed to the gas environment [3, 8,10]. We will now be able to directly investigate the basis of single atom catalysis, for the first time under working conditions, likely leading to the discovery of new mechanisms, and from them we should get new and improved processes; and/or learn how to manage old ones better. Other labs around the world are at the highest resolution restricted to using either ETEM without a probe corrector, or much STEM (or EDX) capability at all, or to using a high vacuum STEM in which samples are exposed to different conditions in transfer and analysis and continuing in-situ methods are of unknown reliability in a reaction atypical high vacuum environment. The relatively new commercial MEMS holders, with gas containing windows [16a,b] are more limited in imaging and analytical performance. The mobile atoms, revealed for the first time in the ESTEM at York using a gas environment with a hot stage [3-6,12], have been shown [7] to modify the previously accepted version of the detailed model of Ostwald Ripening (OR) deactivation mechanism at lower operating temperatures [20,21]. This finding, if confirmed and extended to the single atom level, has profound implications for understanding, and eventually perhaps constructively controlling, or at least usefully influencing, the OR process on a new atomistic level. Just slowing it down even by small amounts would be extremely valuable in highly leveraged economic and environmental terms. An additional important aspect of catalyst activation, referred to in the above, is the reduction of copper oxide Cu2O to Cu metal [15]. The highly reactive surface of copper nanoparticles is protected from the outside atmosphere by an oxide film and the catalyst is only prepared for action when the protective oxide layer is stripped off by treatment with H2 gas. We follow in the ESTEM a similar procedure to that used on a chemical plant, e.g. to prepare a methanation catalyst for action. The project goals have been focused on using disruptive existing experimental ESTEM tools at York, to gain new and transformative single atom level insights into the dynamic properties of nanostructures at the heart of heterogeneous catalyst performance, and in the emerging field of single atom and very small cluster catalysis. The results are contributing to a better focused scientific understanding of key solid state catalyst materials for gas reactions. The direct value of catalysts produced worldwide in 2015 is estimated [to be >£10B pa, with trillions of dollars of product outputs, and economic and environmental opportunities to improve outcomes with wide societal benefits [Re: Royal Society of Chemistry Catalysis estimates, 2010)]. The science the our ESTEM is opening up open up is exciting. AC ESTEM provides a key tool for the study of single atoms in catalysts under reaction conditions with the ability to analyse the structure of the nanoparticles. This is a novel and very important development in terms of impact. As well as new information on the migration of materials from one discrete, in this case metal, nanoparticle to another; it shows the importance of these species leading to active sites. This work relates to parallel on-going Monte Carlo (MC) calculations and provides important input for further calculations of functionality and specific chemical reactivity; through for example the density functional theory (DFT) methods we used for catalytic nanoparticles (at that time studied with temperature and without gas) in our 2012 Nanoletters paper (vol. 12, p.2027 [13]). Based on the novel ESTEM development of Boyes and Gai, the Nanocentre has been successful with a major EPSRC grant (EP/S033394/1) in 2019, for £3.2M supplemented by a further £1M from the University of York, to replace the old technology aberration corrected environmental STEM/TEM instrument dating from 2005 with a new core instrument to be delivered 2Q2021. Our full partnership with EPSRC SuperSTEM Consortium is continuing as the in-situ ESTEM component of the EPSRC National facility for aberration corrected electron microscopy. We have carried out visualisation of reaction kinetics in shape controlled nanoparticles at the atomic level using our ESTEM development (J.Phys,Chem.C. 123 (2019) 14746. We have detailed our recent work in the leading ACS journal: Boyes and Gai et al. Accts. Chem. Res. 53 (2020) 390 References to the Report: 1. E D Boyes and P L Gai, Ultramicroscopy, 67 (1997) 219 Environmental high resolution electron microscopy and applications to chemical science (this paper is the start of breakthrough modern high resolution environmental electron microscopy and reports the technical basis for the subsequent commercial developments widely used across the world) 2. P L Gai, E D Boyes, et al: Henry, MRS Bull, 32 (2007) 1044 Atomic-Resolution Environmental Transmission Electron Microscopy for Probing Gas-Solid Reactions in Heterogeneous Catalysis; (b) Adv. Mat. 10, 1259, 1998. 3. E D Boyes and P L Gai, Comptes Rendu, 15 (2014) 200 Visualising reacting single atoms under controlled conditions : Advances in atomic resolution in situ Environmental (Scanning) Transmission Electron Microscopy (E(S)TEM) 4. E D Boyes, M R Ward, L Lari and P L Gai, Ann Phys (Berlin), 525 (2013) 395 ESTEM imaging of single atoms under controlled temperature and gas environment conditions in catalyst reaction studies 5. E D Boyes and P L Gai, MRS Bulletin, 40 (2015) 600 Visualizing reacting single atoms in chemical reactions: Advancing the frontiers of materials research 6. (a) P L Gai, E D Boyes, J.Phys., Ser 522 (2014) 012002 In-situ environmental (scanning) transmission electron microscopy of catalysts at the atomic level (b) E D Boyes, P L Gai, ibid 012004 Aberration corrected environmental STEM (AC ESTEM) for dynamic in-situ gas reaction studies of nanoparticle catalysts 7. T E Martin, P L Gai and E D Boyes, Chem Cat Chem, 7 (2015) 3705 Dynamic Imaging of Ostwald Ripening by Environmental Scanning Transmission Electron Microscopy 8. P L Gai and E D Boyes, Micros Res and Tech, 72 (2009) 153 Advances in atomic resolution in situ environmental transmission electron microscopy and 1Å aberration corrected in situ electron microscopy 9. J M Thomas, Z Saghi and P L Gai, Topics in Catalysis, 54 (2011) 588 Can a single atom serve as the active site in some heterogeneous catalysts? 10. N R Shiju, K Yoshida, E D Boyes, D R Brown and P L Gai, Cata.Sc.Tech., 1 (2011) 413 Dynamic atomic scale in situ electron microscopy in the development of an efficient heterogeneous catalytic process for pharmaceutical NSAIDS 11. M R Ward, T Hyde, E D Boyes and P L Gai, Chem Cat Chem, 4 (2012) 1622 Nanostructural Studies of Fresh and Road-Aged Practical Pt/SiO2 and Pt-Pd/Al2O3 Diesel Oxidation Catalysts by using Aberration-Corrected (Scanning) Transmission Electron Microscopy 12. P.L. Gai, L. Lari, M R Ward and E D Boyes Visualisation of single atom dynamics Chem. Phys. Lett. 593, 355 (2014). Visualizing single atom dynamics in redox reactions Chem.Phys.Lett. 2014, 13. M Walsh, K Yoshida, A Kuwabara, M Pay, P L Gaia nd E D Boyes. Nanoletters, 2012, 12, 2027 14. P.L. Gai, K. Yoshida, M R Ward, M Walsh, RT Baker, L van de Water, M J Watson and E D Boyes Catal.Sc.Technol. 2016, 6, 2214. 15. A P Lagrow, M R Ward, D Lloyd, P L Gai and E D Boyes Visualizing Cu/Cu2O transition in nanoparticles using ESTEM JACS, 2017, 139, 179. 16. (a) J F Cremer, S Helveg, H W Zandbergen, et al Ultramicroscopy, 108 (2008): Atomic-scale electron microscopy at ambient pressur (b) commercial product versions available from Protochips and DENS, amongst others 17. G A Somorjai, et al, Phys Chem Chem Phys, 9 (2007) 3500 The evolution of model catalytic systems; studies of structure , bonding and dynamics from single crystal metal surfaces to nanopartciles. And from low pressure (<10-3 Torr) to high pressure (>10-3 Torr) to liquid interfaces 18. K Yoshida, A Bright and N Tanaka, J Electron Micr, 61 (2012) 99 19. L F Allard et al: Micr.Micran. 2010, 16.S2 1296 20. P Wynblatt and N Gjostein, Prog. Solid State Chem, 9 (1975) 21 Supported Metal Crystallites 21. T W Hansen, A T Delariva, S R Challa & A K Datye, Accounts Chem Research, 46 (2013) 1720 Sintering of catalytic nanoparticles: particle migration or Ostwald ripening? 
Type Of Material Improvements to research infrastructure 
Year Produced 2014 
Provided To Others? Yes  
Impact The grant holders of - EP/J018058/1, Professor Gai, and Professor Boyes' track record as world leaders in this field has been recognised as follows. During the period, Professor Gai has been elected Fellow of the Royal Society (FRS), Fellow of the Royal Academy of Engineering (FREng) and she was awarded the L'Oreal-UNERSCO Women in Science award as the 2013 Laureate for Europe for excellence in the physical sciences in the continent of Europe. (One woman scientist's work is selected from each continent). Professor Boyes has been elected to Fellowship of the Institute of Physics (FInstP);and was appointed to the EPSRC sponsored committee membership on the future of advanced electron microscopy in the UK. The recognition has come in the invitations to deliver keynote and plenary papers at The Materials Society of America (MRS) meetings in San Francisco (2014/PLG) and in Phoenix, AZ, (2016/EDB), at the Microscopy Society of America meeting in Portland, OR, (2015/EDB) and an Evening Discourse (2014/PLG) at the Royal Institution of Great Britain. Numerous Publications and organisation of the International at the IOP EMAG Conference in York, 2013 with plenary and key-note papers [6]; and others have also resulted. Full partnership with EPSRC SuperSTEM Consortium: Largely on the basis of this project, York has been invited to become the first and so far only new full partner in the consortium of Universities running EPSRC's National Facility for Aberration Corrected Electron Microscopy, or SuperSTEM, and in the process to extend the access of other user groups to the unique facility at York. Work has so far been done in collaboration with the Universities of Leeds, Oxford and UCL in the UK, and with Cadiz (Spain) and Nagoya and Okinawa (Japan). Collaboration with UK Industry: There has been significant industrial collaboration leading to joint publications with Johnson Matthey Plc (JM), a FTSE 100 company and world leader in precious metals and catalysis. JM was also a strong supporter of our grant proposal and the interaction continues to be further strengthened at the strategic and tactical levels. The latter include CASE studentships, access to their extensive technical resources for both specimen preparation (including custom preparation to our specifications where needed) and testing, and regular direct technical work for which they pay the University. Based on the novel ESTEM development of Professor Boyes and Professor Dame Pratibha Gai, the York Nanocentre has been successful with a major EPSRC grant (EP/S033394/1) in 2019, to replace the old technology instrument dating from 2005 with a new core instrument to be delivered 2Q2021. Professor Gai and Prof Boyes have been elected Fellows of the Microscopy Society of America in 2019. 
 
Title Computational models for strain analysis in nanoparticles and for ceria vacancies 
Description Computational models for strain analysis in nanoparticles (Nanoletters Vol 12, p.2027, 2012) and models of ceria vacancies in gold ceria catalysts(Catal Sc and Tech. DOI: 10.1039/c5cy01154j). 
Type Of Material Data analysis technique 
Year Produced 2012 
Provided To Others? Yes  
Impact High profile publications and collaborations 
 
Description Nagoya University, Japan 
Organisation Nagoya University
Country Japan 
Sector Academic/University 
PI Contribution Joint publications resulting from joint work at Nagoya and York by the staffs of each institution, with in each case access to novel facilities not available at the other place
Collaborator Contribution Joint publications resulting from joint work at Nagoya and York by the staffs of each institution, with in each case access to novel facilities not available at the other place
Impact Joint publications resulting from joint work at Nagoya and York by the staffs of each institution, with in each case access to novel facilities not available at the other place: K Yoshida, A N Bright, M R Ward, L Lari, X Zhang, T Hiroyama, E D Boyes and P L Gai Dynamic wet-ETEM observation of Pt/C electrode catalysts in a moisturized cathode atmosphere Nanotechnology, 25, 425702 (2014). K Yoshida, X Zhang, T Hiroyama, E D Boyes and P L Gai. Development Aberration Corrected Wet-ETEM System and Its Application to Pt/Carbon Fuel Cell Catalysts in Moisturized Gases Environments International Microscopy Congress, Prague, 2014 (poster + publd Proceedings)
Start Year 2012
 
Description Technical University Denmark 
Organisation Technical University of Denmark
Country Denmark 
Sector Academic/University 
PI Contribution Scientific collaboration
Collaborator Contribution Scientific collaboration
Impact Book Chapter
Start Year 2015
 
Description University of Cadiz Spain 
Organisation University of Cadiz
Department Department of Chemistry
Country Spain 
Sector Academic/University 
PI Contribution Joint publication and student training
Collaborator Contribution joint publication
Impact ACS Nano publication
Start Year 2012
 
Description University of Leeds 
Organisation University of Leeds
Country United Kingdom 
Sector Academic/University 
PI Contribution In-situ studies of nuclear materials and training of student
Collaborator Contribution characterisation
Impact Publication in progress
Start Year 2014
 
Description University of Oxford ; Quantitative measurement of metal atom particles 
Organisation University of Oxford
Department Faculty of English
Country United Kingdom 
Sector Academic/University 
PI Contribution University of York ESTEM microscopy
Collaborator Contribution Software development
Impact Under progress towards publication
Start Year 2016
 
Description University of Paris 
Organisation University Paris Sud
Country France 
Sector Academic/University 
PI Contribution Scientific collaboration
Collaborator Contribution Scientific collaboration
Impact Publication
Start Year 2014
 
Description University of Sheffield 
Organisation University of Sheffield
Country United Kingdom 
Sector Academic/University 
PI Contribution Scientific collaboration
Collaborator Contribution Scientific collaboration
Impact seminars student training
Start Year 2013
 
Description University of St Andrews Scotland 
Organisation University of St Andrews
Country United Kingdom 
Sector Academic/University 
PI Contribution Scientific collaboration
Collaborator Contribution Scientific collaboration
Impact Joint publication
Start Year 2014
 
Description IOP/RMS/EPSRC Committee on future of high-end electron microscopy in the UK 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Working party, multiple meetings, production of future scope of reports
Year(s) Of Engagement Activity 2014
 
Description In-situ ESTEM 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other audiences
Results and Impact Keynote talk at the Materials Research Society (MRS), USA Spring conference, Phoenix, AZ, USA
Year(s) Of Engagement Activity 2016
 
Description In-situ ETEM of catalysts under reaction conditions 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other audiences
Results and Impact Invited keynote talk at the Spring Materials Research Society (MRS) Meeting in San Francisco, California
Year(s) Of Engagement Activity 2014
 
Description Organisation :UK International conference -EMAG-2013 at University of York, sponsored by Inst of Physics; Public lectures at Ri and IOP 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact • Organisation of the UK International conference on electron Microscopy, -EMAG-2013 at University of York, sponsored by the Institute of Physics, with plenary, invited and contributed presentations by the staff.
• Mostly invited presentations were also made at:
Microscopy and microanalysis Conference (MMC) Manchester, 2015;
Microscopy Society of America, Portland Oregon, USA 2015 (invited and contributed talks)
Materials Research Society (MRS) 2014 : invited keynote lecture
MRS 2016 (invited and contributed talks)
Arizona State University workshop on aberration corrected-EM (2016) (invited)
Scandem Microscopy conf., Linkoping, Sweden (invited)
International Microscopy Congresss, Prague (Invited and contributed talks)
Year(s) Of Engagement Activity 2013