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Projects: Projects for Investigator
Reference Number EP/G065381/1
Title Materials World Network: Role of Surface Chemistry and Structure in Oxygen Surface Exchange in Transition Metal Perovskites
Status Completed
Energy Categories Not Energy Related 85%;
Hydrogen and Fuel Cells(Fuel Cells, Stationary applications) 5%;
Hydrogen and Fuel Cells(Hydrogen, Hydrogen production) 5%;
Hydrogen and Fuel Cells(Fuel Cells, Mobile applications) 5%;
Research Types Basic and strategic applied research 100%
Science and Technology Fields PHYSICAL SCIENCES AND MATHEMATICS (Chemistry) 50%;
PHYSICAL SCIENCES AND MATHEMATICS (Metallurgy and Materials) 25%;
UKERC Cross Cutting Characterisation Not Cross-cutting 100%
Principal Investigator Professor PA Thomas
No email address given
University of Warwick
Award Type Standard
Funding Source EPSRC
Start Date 01 October 2009
End Date 31 March 2013
Duration 42 months
Total Grant Value £1
Industrial Sectors No relevance to Underpinning Sectors
Region West Midlands
Programme Physical Sciences
Investigators Principal Investigator Professor PA Thomas , Physics, University of Warwick (99.998%)
  Other Investigator Professor CF McConville , Physics, University of Warwick (0.001%)
Professor ME (Mark ) Smith , Vice-Chancellor's Office, Lancaster University (0.001%)
Web Site
Abstract As global concerns about climate change due to greenhouse gas emissions mount, there is a very urgent need for high efficiency power generation technologies. Solid state electrochemistry provides very interesting technological solutions to meet this need. Examples of such technologies include - solid oxide fuel cells (SOFCs), ceramic ion transport membranes (ITMs) for hydrogen generation, and solid oxide electrolyzers. Underlying many of these devices is the phenomenon of oxygen exchange from the gas phase into a transition metal perovskite oxide which is typically used as one of the two electrodes in such devices. Once the architecture of such devices is optimized, i.e. the electrodes made sufficiently fine and porous and the solid electrolyte thickness reduced to a practicable minimum, the basic step of reversible oxygen exchange between the gas phase and the transition metal perovskite oxide rate controls the performance of such devices. Prior studies of this basic process have been fragmentary - employing geometrically irregular porous electrodes and phenomenological models in which the surface exchange and transport coefficients are derived from the overall performance of the devices.The objectives of the proposed work are: to correlate the details of the electronic structure of the bulk and the surface of the oxides to the oxygen exchange rates, to correlate surface structure and structure reconstructions with the oxygen exchange process, and to obtain orientation relationships of surfaces and of buried interfaces in solid state electrochemical devices.A research approach in which the surfaces of such transition metal perovskite oxides are studied using clean, well-defined, model epitaxial thin films on suitably chosen single crystal substrates is proposed. Such films allow for the systematic examination of these materials using a suite of analytical tools which probe the crystal and electronic structure of the bulk and of the surface. Bulk and surface crystal structure of the films will be studied using a variety of x-ray diffraction tools and transmission electron microscopy and the electronic structure will be probed using a variety of electronic spectroscopic tools. In some of the experiments we plan to combine high temperature in-situ x-ray diffraction experiments with kinetic measurements using an electrical conductivity relaxation technique. We also plan to supplement the structural and kinetics studies using O-17 nuclear magnetic resonance and O-18 secondary ion mass spectroscopy. Finally, density functional theory will be used to model the crystal and electronic structure of such thin films as a support to the experimental program.The personnel involved in the project represent rich and diverse disciplinary backgrounds, working across a transatlantic link that has been established between Boston University and the University of Warwick. The two teams bring a balance of skill sets and scientific tools that is essential to the success of this complex project.The intellectual merit of the proposed work is the posing and answering of some very fundamental questions regarding the role of surface chemistry and structure of transition metal perovskite oxides used as electrodes in many solid state electrochemical devices on the oxygen exchange process.The broader impacts of the proposed work are two-fold - on education and on society at large. The educational impacts include the training of junior scientists and graduate students in the urgently important area of materials for clean energy, exposure of graduate students early in their careers to interdisciplinary research across transatlantic educational institutions and at national labs, and training of undergraduate students in research. The societal impacts include the mitigation of environmental concerns due to emission of greenhouse gases and outreach to minority students
Publications (none)
Final Report (none)
Added to Database 11/11/11