Emergent Nanomaterials (Critical Mass Proposal)

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

Abstract

In recent work we have identified a very powerful and extensive phenomenon, the constrained production of nanoparticles that opens up a new field impinging on chemistry, materials science and physics. The dispersion, stability, versatility and coherence with the substrate impart quite significant properties to the emergent nanoparticles opening up a major new topic. The process is driven by the lattice decomposition of a metal oxide under reduction by various means. Conventional thinking considers this as a simple phase separation; however, by careful control of the defect chemistry and reduction conditions, a very different process can be achieved. These nanoparticles emerge from the substrate in a constrained manner reminiscent of fungi emerging from the earth. The emergent nanoparticles are generally dispersed evenly with a very tight distribution often separated by less than one particle diameter.

Here we will explore the composition and reaction space conditions necessary to optimise functionality, structure and applocability. We will also seek to better understand this phenomenology relating to correlated diffusion, driving energetics and mechanism of emergence. Further work is necessary to understand the critical dependence of composition in a very extensive domain of composition space depending upon charge and size of the A-site cations, oxygen stoichiometry and transition metal redox chemistry. Of particular importance is to understand the nature of the interaction between the nanoparticle and the substrate addressing the evolution of the nanoparticles from the surface and how the particles become anchored to the substrate. Exolved metals can react to form compounds whilst maintaining the integrity of the nanostructural array and this offers much potential for further elaboration of the concept.

We will investigate the important catalytic, electrocatalytic and magnetic physics properties arising at constrained emergent particles, driven by dimensional restriction. Emergent nanomaterials provide very significant surface-particle interactions and promise new dimensions in catalysis. The electrochemical reactions in devices such as batteries and fuel cells are restricted to the domain very close to the electrolyte electrode interface. Emergent materials can be applied in exactly this zone.

Planned Impact

We are proposing to develop our understanding and ability to control Emergent Nanomaterials, a new class of materials that due to their constrained nature and specific dimensionality offer remarkable new functionalities and capabilities. This could offer step-change new technologies and applications.
The work will be of considerable interests to chemists, physicists and materials scientists interested in structure property relations and the fundamental science determining functional properties. The area will also be of great interest to engineers looking to develop new devices, for energy storage and conversion, information storage, catalytic conversion and optoelectronics. There are also interesting synergies with biological structures and geochemical transformations.
The possible technological implications are very significant and there is already considerable excitement in the catalytic and energy conversion arenas. Companies such as Johnson Matthey, AFC Energy, Ceres Power and Rolls Royce are already interested and engaged. These new structures offer considerably improved stability and functionality and there is already a clear home for emergent nanomaterials in these arenas. Likely examples are exhaust catalysts, bioenergy reforming, low and high temperature fuel cell/electrolyser electrodes, plasmonic solar cell, lithium batteries and sensors. As we learn more we see opportunities to greatly reduce cost over existing systems and there are clear possibilities to greatly reduce precious metal requirements or even remove the need altogether. This addresses the strategic availability of the so-called critical elements.
We also expect to find important new physical phenomena as we know how much strain and constrained dimensions impacts upon such properties. This in turn may yield important new technologies that we can see commercialised in the UK.
There are important prospects to benefit society, not only do we see exciting technological advances, but also we see great prospects to improve energy security, energy efficiency and energy storage in environmentally friendly processes. In other words, appropriate introduction of new materials concepts such as these will greatly reduce CO2 production and can even assist in CO2 removal through utilisation. Undoubtedly these new technology advances, in energy and beyond, offer secured employment and new jobs. In turn this provides taxes and reduces cost for government to mediate climate change and hence benefits society and government.
Last but not least, this project will help shape the training and vision of the next generation of researchers by placing them in a truly multidisciplinary programme which will encourage fertile scientific thinking across techniques and disciplines, while providing clear scope of high-level scientific and national strategic targets.
 
Description New approaches have been developed to exolve nanoparticles at low temperature and important advances made in exolving platinum group metals at low loadings and high activities.
Exploitation Route Under discussion with relevant companies
Sectors Chemicals,Energy,Environment

 
Title METHOD FOR PRODUCING AN ELECTRODE CATALYST FROM A PEROVSKITE METAL OXIDE 
Description The invention relates to a method of producing electrode materials for solid oxide cells which comprises applying an electric potential to a metal oxide which has a perovskite crystal structure. The resultant electrode catalyst exhibits excellent electrochemical performance. The invention extends to the electrode catalyst itself, and to electrodes and solid oxide cells comprising the electrode catalyst. 
IP Reference CA3030088 
Protection Patent application published
Year Protection Granted 2018
Licensed Commercial In Confidence
Impact -
 
Description Invited Talk 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact The greatest challenge facing Solid oxide cells (SOC), in both fuel and electrolysis cell modes (i.e SOFCs and SOECs) is to deliver high, long-lasting electrocatalytic activity while ensuring cost and time-efficient electrode manufacture. Ultimately, this can best be achieved by growing appropriate nanoarchitectures under operationally relevant conditions, rather than through intricate ex situ procedures.

In our approach, metal particles are grown directly from the oxide support though in situ redox exsolution. We demonstrated that by understanding and manipulating the surface chemistry of an oxide support with adequately designed bulk (non)stoichiometry, one can control the size, distribution and surface coverage of produced particles. We also revealed that the emergent particles are generally epitaxially socketed in the parent perovskite which appears to be the underlying origin of their remarkable stability, including unique resistance of metal particles to agglomeration and to hydrocarbon coking, whilst retaining catalytic activit.

Operando redox treatments yield emergent nanomaterials at potentials in excess of 2V. Here we apply this technique to drive steam, CO2 and coelectrolysis processes at emergent metals and alloy particles.
Year(s) Of Engagement Activity 2020
URL https://ecs.confex.com/ecs/prime2020/meetingapp.cgi/Paper/143913
 
Description Invited Talk 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact European School on Ceramics for Energy Conversion and Storage (EnergyCeram)
The online school aims at presenting a current overview of ceramic materials and technologies for selected energy applications. A topical focus is put on high-temperature power generation (gas turbines, concentrated solar power) and electrochemical applications based on ionic transport (solid oxide fuel cells, gas separation membranes, electrochemical storage).
After a brief introduction of each application field including targets for properties, the relevant ceramic materials will be reviewed and evaluated. In order to be integrated in real devices, they need to fulfil numerous, often contradictory conditions, such as highest ionic and/ or electronic conductivity, stability during operation, processability, etc.

The used online platform will allow for personal interactions (including video chat and screen sharing). Enough breaks are foreseen to stimulate exchanges, offering the opportunity to chat with other participants and meet new people face-to-face or in small groups!
Year(s) Of Engagement Activity 2020
URL https://congress.dkg.de/event/eu_spring_school_001/