Hydrogen Free Selective Hydrogenation: Step Changing Innovation in Catalysis by Gold

Lead Research Organisation: University of St Andrews
Department Name: Chemistry

Abstract

This project sets out the ambitious goal of achieving atom efficiency and enhanced catalytic activity in "hydrogen free" hydrogenation in continuous flow operation. The work brings together two established research groups with expertise in heterogeneous catalyst preparation, characterisation and reaction engineering (Keane, Chemical Engineering, Heriot-Watt University) and catalytic surface science (Baddeley, Chemistry, St. Andrews University). The synergy that results from this collaboration allows innovation with respect to catalyst design and optimisation with the integration of fundamental and in situ surface science measurements into catalyst synthesis/characterisation and testing. Prior work has established ultra-selectivity in nitro- and carbonyl- group reduction over supported Au catalysts. However, reaction rates were appreciably lower than standard non-selective (Pt, Pd and Ni) metal catalysts due to the activation energy barrier for H2 dissociative adsorption on Au. Gold promoted hydrogenation is conducted in excess H2 that remains unreacted, resulting in fundamental process inefficiency and unsustainability. We propose an innovative coupling of catalytic dehydrogenation (as a source of reactive hydrogen) with hydrogenation. Preliminary data provide proof of concept for the coupling of 2-butanol dehydrogenation with furfural hydrogenation (to furfuryl alcohol) over physical mixtures of oxide supported Au and Cu. We have recorded (orders of magnitude) enhanced H2 utilisation in the coupled system and elevated selective hydrogenation rate relative to the single component Au catalyst. Furfural is a biomass derived heterocyclic aldehyde that can serve as a non-petroleum based renewable feedstock. The target furfuryl alcohol product is a high value chemical used to manufacture resins/rubbers/adhesives and as a chemical building block for drug synthesis. Our proposed coupling reaction is step changing and closes the sustainability gap in terms of unreacted hydrogen. As Au in effect 'borrows' hydrogen generated in situ via Cu promoted dehydrogenation, the coupled system circumvents the use of compressed H2, which has important safety implications for large scale chemical production.
We have set out to gain a fundamental understanding of coupled dehydrogenation/ hydrogenation through a programme of surface science measurements involving STM, RAIRS, XPS, TPD and DRIFTS analysis that will provide critical information on reactant/product surface interactions. The work will first focus on reaction coupling over supported Au and Cu physical mixtures, addressing sensitivity to metal particle size and electronic character, the role of the metal/support interface, hydrogen spillover, transport and reactivity. The molecular-level mechanistic understanding provided by the surface science methodologies coupled with a determination of the influence of the gas phase species on surface composition (MEIS) will inform synthesis of supported bimetallics (Au-Cu) with a programme of rational catalyst design directed at achieving the catalyst formulation that delivers the optimum hydrogen utilisation efficiency. Collaboration with Syngenta and Sasol Technology UK as industrial partners will ensure that the work delivers real commercial impact. The ultimate deliverable is a catalytic process than can deliver 100% selectivity at elevated rates in the sustainable hydrogen free hydrogenation of renewable furfuran platform reactants.
This proposal fits well with the EPSRC shaping capability agenda, notably the "catalysis" theme, underpinning "energy efficiency", "sustainability" and "frontier manufacturing" priorities. Moreover, the work tackles head on the "Dial-a-Molecule-100% Efficient Synthesis" Grand Challenge with a programme of work directed at the "catalytic paradigms for 100% efficient synthesis" theme.

Planned Impact

Commercialisation of heterogeneous catalysts is critical throughout the chemical and pharmaceutical sectors. Advances in sustainable catalytic processes are paramount in the drive to cleaner production. We propose an innovative coupling of dehydrogenation with hydrogenation harnessing the ultra-selective action of supported Au catalysts in the atom efficient conversion of biomass-derived furfural to high value furfuryl alcohol without recourse to an external supply of pressurised hydrogen. We have demonstrated enhanced hydrogen utilisation in the coupled system with significantly higher hydrogenation rates than recorded for conventional operations. Our ultimate goal of identifying the optimum supported (Au-Cu) bimetallic catalyst formulation for "hydrogen free" hydrogenation of furan platform chemicals to high value products will represent a step change in hydrogenation operations, impacting on product inventories that run to millions of tonnes per year.
Economy
Our coupled system circumvents the use of compressed hydrogen, which has important safety, energy usage and cost implications for large scale chemical production. Delivery of atom efficient hydrogenation will have enormous impact across the UK chemical industry in a 10-50 year time-frame. This is recognised by our industrial partners (Syngenta and Sasol) with whom we will work to ensure commercial exploitation. Existing routes to fine chemicals involve high pressure batch processes that deliver low product yields and require multistage separations and waste treatment. The commercial sector face economic pressures including escalating disposal charges and increasing raw material/energy costs, which can be addressed by use of platform chemicals from bio-renewable resources, alternative hydrogen sources and improved process selectivity. This project will strengthen UK leadership in this field, providing significant employment and wealth creation.
Society and Environment
Cleaner, safer chemical production is essential to meet UK environmental and health/safety legislation, addressing crucial societal needs. We tackle sustainability in sourcing the organic reactants and supply of hydrogen. The US "National Academies", which bring together committees of experts across science and technology, has identified "Grand Challenges in Sustainability". These include "Green and Sustainable Chemistry and Engineering", directed at discovering new ways to carry out chemical transformations based on the ultimate premise that "it is better to prevent waste than to clean it up after it is formed": this underpins our proposal.
Scientist Training
Barriers exist in the commercial application of sustainable processing, which are largely a result of inadequate education, management and training of chemists/chemical engineers. A driver in this proposal is to provide research training that cuts across discipline boundaries. The PDRAs will draw on the Scottish Institute for Enterprise 'Business and Enterprise' training to meet the aims of RCUK to develop entrepreneurship and enterprise skills. Industry and/or academia will benefit via the provision of highly skilled individuals with unique technical and commercial skills that can contribute directly to the chemical sector as effective sustainability practitioners.
Cross-Disciplinary Beneficiaries
Real impact in achieving the ambitious goal of atom efficient chemical processing requires a strategic integration of cross-disciplinary research methodologies. This collaboration will enhance the activities of both investigators. The incorporation of catalyst testing in flow operation to inform surface measurements will redefine Baddeley's (Chem, USTAN) research while Keane (Chem Eng, HWU) will consider advanced surface analysis as a tool for catalyst design. This proposal exemplifies the required synergy between chemists and chemical engineers identified by the US National Academies as critical to achieving advances in sustainable processing.

Publications

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Grillo F (2018) Structure and Reactivity of Cu-doped Au(111) Surfaces in e-Journal of Surface Science and Nanotechnology

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Grillo F (2019) Structural and electronic characterization of Cu/Au(111) near-surface alloys in Japanese Journal of Applied Physics

 
Description The project is a collaboration with colleagues from Chemical Engineering at Heriot Watt University. Our colleagues at HWU have focussed on catalytic testing and optimisation of catalytic performance while our role has been to probe the surfaces of powder catalysts with infra-red spectroscopy under operating conditions in order to identify the species present and how the presence of these species correlates with catalytic performance. We developed a diffuse reflectance set up which allows IR measurements on powder catalysts under operating conditions (i.e. in a flow of reactant gases and at operating temperature). An online quadrupole mass spectrometer samples the exhaust gases and monitors catalytic perfomance.

A key aspect of the project has been to compare the behaviour of catalysts where Cu and Au particles are isolated from each other with catalysts where Cu and Au have been allowed to intermix. In the next year, we will submit papers with our colleagues from Heriot Watt University reporting DRIFTS studies addressing the comparison between the surface chemistry of pure Cu and Au particles with alloyed particles. In addition, we will submit a paper in collaboration with our colleagues from Huddersfield University and Universidade Federal do Rio Grande do Sul (Brazil) examining the temperature dependence of alloy formation in model catalyst systems consisting of Cu and Au nanoparticles deposited onto planar oxide supports.

We have published a paper reporting the formation of ordered CuAu alloys on Au single crystal surfaces. A second paper is under review examining the electronic properties of CuAu surface alloys. We have investigated the surface chemistry of CuAu alloys in comparison with pure Cu and Au surfaces and this will be the subject of an additional paper to be submitted.
Exploitation Route The combined findings of the Heriot Watt and St Andrews groups should lead to others (academics & industrial catalytic chemists) developing selective hydrogenation catalysts for operation at 1 bar pressure.
Sectors Chemicals

 
Description Our work on the structure and composition of CuAu alloy surfaces combined with earlier work by F Grillo on corrosion inhibition has led to an interaction with Sunamp (an SME specialising in renewable energy storage) and the recent award of EPSRC impact acceleration funding
First Year Of Impact 2018
Sector Energy
Impact Types Societal

 
Title Development of an instrument for in situ DRIFTS measurements on catalyst powders with GC/MS analysis of exhaust gases. 
Description We are able to acquire IR spectra of species adsorbed on a powder catalyst under reaction conditions (at elevated temperature, 1 bar pressure in a flow of reactant gases). We can analyse the exhaust gas composition with a combination of GC and mass spectrometry 
Type Of Material Improvements to research infrastructure 
Year Produced 2017 
Provided To Others? No  
Impact Researchers from other research areas (materials, fuel cells) have expressed an interest in using this facility 
 
Title Structure and reactivity of Cu-doped Au(111) surfaces (dataset) 
Description This paper contains origial data and a review section. Original data are scanning tunnelling microscopy (STM) images, which can accessed using the WsXM software and high resolution electron energy loss spectroscopy (HREELS) spectra, which can be accessed using any text editor. 
Type Of Material Database/Collection of data 
Year Produced 2018 
Provided To Others? Yes  
 
Description Analysis of medium energy ion scattering data from oxide supported Cu/Au nanoparticles 
Organisation Federal University of Rio Grande do Sul
Country Brazil 
Sector Academic/University 
PI Contribution My research team have synthesised model catalysts consisting of ultrathin oxide films grown on Si wafers. Cu and Au nanoparticles have been deposited by metal-vapour deposition onto the oxide surfaces and the samples have been characterised by medium energy ion scattering (MEIS) at the University of Huddersfield.
Collaborator Contribution The group of Professor Pedro Grande (Physics, UFRGS) have analysed our MEIS data and are analysis data recently acquired at the MEIS facility. Our collaborators at the University of Huddersfield have worked with us in the acquisition of MEIS data. We are currently drafting a first publication arising from this collaboration.
Impact We intend to publish our collaborative work in the next 12 months
Start Year 2017
 
Description Analysis of medium energy ion scattering data from oxide supported Cu/Au nanoparticles 
Organisation University of Huddersfield
Department School of Computing and Engineering
Country United Kingdom 
Sector Academic/University 
PI Contribution My research team have synthesised model catalysts consisting of ultrathin oxide films grown on Si wafers. Cu and Au nanoparticles have been deposited by metal-vapour deposition onto the oxide surfaces and the samples have been characterised by medium energy ion scattering (MEIS) at the University of Huddersfield.
Collaborator Contribution The group of Professor Pedro Grande (Physics, UFRGS) have analysed our MEIS data and are analysis data recently acquired at the MEIS facility. Our collaborators at the University of Huddersfield have worked with us in the acquisition of MEIS data. We are currently drafting a first publication arising from this collaboration.
Impact We intend to publish our collaborative work in the next 12 months
Start Year 2017
 
Description Towards "Hydrogen free" hydrogenation of furfural to furfural alcohol using Au/Cu catalysts. An investigation of model systems. 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Postgraduate students
Results and Impact I attended the Liverpool Catalysis Summer School (University of Liverpool 17.07.2017) and presented a poster at the evening poster session.
.
Year(s) Of Engagement Activity 2017
 
Description A talk at Interdisciplinary Surface Science Conference - 21 (Manchester) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact A presentation was given on the development of the Cu/Au project. Scanning tunnelling microscopy (STM), surface vibrational spectroscopy (HREELS) and temperature desorption spectroscopy (TDS) results on model systems prepared in ultra-high vacuum conditions were presented. Initial atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) results on model systems prepared at ambient conditions were presented. The audience contained researchers interested in the surface structure and chemistry of bimetallic systems as well as researchers from other areas of surface science. The audience showed considerable interest in the presentation and scientific discussions proved useful in guiding subsequent experiments on model catalysts.
Year(s) Of Engagement Activity 2017
 
Description Conference presentation, ACSIN-14 and ICSPM26, Sendai, Japan 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact A presentation was delivered on the development of the Cu/Au project, with focus on the structure of copper adlayers on Au(111) surfaces. Scanning tunnelling microscopy (STM) and Syinchrotron Radiation (photoemission, X-ray diffraction) measurements on model systems prepared in ultra-high vacuum conditions were presented. The audience contained researchers interested in the surface structure and chemistry of bimetallic systems as well as researchers from other areas of surface science. The audience showed considerable interest in the presentation and scientific discussions proved useful in guiding subsequent experiments. A conference proceeding paper was prepared, has been submitted to Jpn. J. Appl. Phys. and is currently under review.
Year(s) Of Engagement Activity 2018
URL https://dora.bk.tsukuba.ac.jp/event/acsin14/
 
Description Conference presentation, ECOSS 32, Grenoble, France 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact A presentation was given on the development of the Cu/Au project. Initial scanning tunnelling microscopy (STM), surface vibrational spectroscopy (HREELS) and temperature desorption spectroscopy (TDS) results on model systems prepared in ultra-high vacuum conditions were presented. The audience contained researchers interested in the surface structure and chemistry of bimetallic systems as well as researchers from other areas of surface science. The audience showed considerable interest in the presentation and
asked relevant questions related to the chemistry of the process described and the instrumentation which is still being developed.
Year(s) Of Engagement Activity 2016
 
Description Conference presentation, HRDP8, London, Canada (Prof C Baddeley) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact A presentation on the use of medium energy ion scattering (MEIS) with surface vibrational spectroscopy and scanning tunnelling microscopy (STM) to characterise the composition of bimetallic model catalyst surfaces and the influence of catalytically important reagents on the surface composition. Among the attendees at the meeting were the research group of Professor Pedro Grande (Univerade Federal Do Rio Grande Do Sul, Brazil). This group is world-leading in the analysis of nanostructured materials using MEIS and a primary purpose of attending the meeting was to consolidate a collaboration with Grande's group in order to characterise MEIS data acquired by my group at the MEIS facility at the University of Huddersfield. To further strengthen the collaboration, a MSc student from Grande's group applied for a Brazilian scholarship to study in my group in St Andrews. The outcome of the application will be known in April 2017.
Year(s) Of Engagement Activity 2016
 
Description Conference presentation, ISSS8, Tsukuba, Japan 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact A presentation was given on the development of the Cu/Au project, with focus on the structure and reactivity of Cu-doped Au(111) surfaces. Scanning tunnelling microscopy (STM) results on model systems prepared in ultra-high vacuum conditions were presented, along with a review of previously reported findings. The audience contained researchers interested in the surface structure and chemistry of bimetallic systems as well as researchers from other areas of surface science. The audience showed considerable interest in the presentation and scientific discussions proved useful in guiding subsequent experiments. A conference proceeding paper was prepared.
Year(s) Of Engagement Activity 2017
URL http://www.sssj.org/isss8/
 
Description EaStCHEM Conference for Early Career Researchers, Edinburgh, UK 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact A presentation was given on the development of the Cu/Au project, with focus on possible corrosion inhibition carachteristics of such a systems. Scanning tunnelling microscopy (STM), surface vibrational spectroscopy (HREELS) and temperature desorption spectroscopy (TDS) results on model systems prepared in ultra-high vacuum conditions were presented. Further the adsoprion of anti corrosive molecules was considered. The audience contained researchers covering all areas of Chemistry. Valuable insight was provided by discussions with experts in materials chemistry, heterogeneous and homogeneous catalysis. This insight has been fed back into the development of the project. As a result, links with industrial partners were facilitated.
Year(s) Of Engagement Activity 2018
 
Description EaStCHEM Conference for Early Career Researchers, Edinburgh, UK 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact A presentation was given on the development of the Cu/Au project. Initial scanning tunnelling microscopy (STM), surface vibrational spectroscopy (HREELS) and temperature desorption spectroscopy (TDS) results on model systems prepared in ultra-high vacuum conditions were presented. The audience contained researchers covering all areas of Chemistry. Valuable insight was provided by discussions with experts in materials chemistry, heterogeneous and homogeneous catalysis. This insight has been fed back into the development of the project.
Year(s) Of Engagement Activity 2016
 
Description Functionalising Surfaces Symposium, Burlington House - RSC, London, UK 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact A presentation was given on the catalytic activity and corrosion inhibition character of the Cu/Au system as is, and after functionalising the surface with several organic molecuels. The audience contained researchers covering all areas of Surface Chemistry. Valuable insight was provided by discussions with experts in materials chemistry, heterogeneous and homogeneous catalysis. This insight has been fed back into the development of the project
Year(s) Of Engagement Activity 2019
 
Description Influence of structure and composition on the surface chemistry of bimetallic Cu/Au model catalysts 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Talk at the American Chemical Society Fall meeting in Boston, USA. Discussions were held with other conference delegates who had attended the session regarding the hydrogen free hydrogenation catalytic system that we are investigating.
Year(s) Of Engagement Activity 2018
 
Description Invited talk at Surface Science Day at University of Liverpool 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact The University of Liverpool organised a Surface Science Day - where many of the UK's surface science research leaders gave invited talks. Discussions over the course of the workshop led to ideas for potential collaborative research.
Year(s) Of Engagement Activity 2017
URL https://www.liverpool.ac.uk/surface-science/surface-science-day-2017/
 
Description Invited talk at University of Edinburgh 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Postgraduate students
Results and Impact I gave a departmental colloquium at the University of Edinburgh. In addition to the presentation, I had extensive one-to-one discussions with a number of research leaders in the School of Chemistry which may lead to future collaborative research.
Year(s) Of Engagement Activity 2017
 
Description Invited talk at the University of Huddersfield 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact I gave an invited talk at the kick-off meeting for the UK National Ion Beam Centre on my research involving medium energy ion scattering (MEIS). The MEIS facility at Huddersfield University forms part of the UK National Ion Beam Centre. The audience contained researchers covering a wide range of ion beam techniques. My talk generated interest in the capabilities of MEIS as a method for depth profiling the composition of surfaces and nanoparticles.
Year(s) Of Engagement Activity 2017
 
Description Surface Science: Beyond UHV, Burlington House - RSC, London, UK 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact A presentation was given on the surface reactivity and the corrosion inhibition character of the Cu/Au system, from model studies in ultra-high vacuum, to real conditions at atmospheric pressure. The audience contained researchers covering all areas of Surface Chemistry. Valuable insight was provided by discussions with experts in materials chemistry, heterogeneous and homogeneous catalysis. This insight has been fed back into the development of the project.
Year(s) Of Engagement Activity 2017
 
Description The surface chemistry of 2-butanol on Au , Cu and AuCu single crystal surfaces. Alternative sources of atomic H for "hydrogen free" hydrogenation reactions. 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Postgraduate students
Results and Impact Rory Megginson (PhD student working on the EPSRC project) presented a poster at the Surface Science Day (University of Birmingham, 17/12/2018). The poster was awarded a prize in the 'best poster' competition.
Year(s) Of Engagement Activity 2018