Atomistic energetics integrated with continuum level models are providing transformative insights into the fundamental mechanisms controlling electrochemical processes and their related technologies. For example, we have worked extensively in catalysis for both Proton Exchange Membrane Fuels Cells (PEMFCs) and Solid Oxide Fuel Cells (SOFCs). In PEMFCs our work has focused on the stability of small nanoparticle Pt and Pt alloy catalysts, a critical issue for avoiding catalyst degradation in PEMFC applications. We have integrated empirical and ab initio data to understand and predict how these particles dissolve under operating conditions and the coupling of their stability to their nanoscale thermodynamics and kinetics[4]. In SOFCs we have helped develop new catalytic understanding and materials through studying the perovskite cathode, including understand defect chemistry[5] and surface oxygen reactions, establishing descriptors for catalytic activity[6], and developing the first full mechanistic models for the oxygen reduction reaction. We also study electrochemical processes in batteries, including properties of Li-ion battery cathodes and coatings to enhance their performance.
[4] E. F. Holby and D. Morgan, Application of Pt Nanoparticle Dissolution and Oxidation Modeling to Understanding Degradation in PEM Fuel Cells, Journal of the Electrochemical Society 159, p. B578-B591 (2012).
[5] Y. L. Lee and D. Morgan, Ab initio and empirical defect modeling of LaMnO3 +/-delta for solid oxide fuel cell cathodes, Physical Chemistry Chemical Physics 14, p. 290-302 (2012).
[6] Y. L. Lee, J. Kleis, J. Rossmeisl, Y. Shao-Horn, and D. Morgan, Prediction of solid oxide fuel cell cathode activity with first-principles descriptors, Energy & Environmental Science 4, p. 3966-3970 (2011).
(a) Schematic of the complex processes involved in O2 reduction reaction on the SOFC cathode. (b) Demonstration that bulk oxygen 2p band center can be a successful descriptor for the surface exchange coefficient (strongly correlated with O2 reduction reaction catalytic activity) for a perovskite SOFC cathode (from Ref. [6]).