2, Cornell University, Ithaca, New York, United States
The efficiencies of electrochemical energy conversion devices such as electrolyzers and fuel cells depend on the efficacy of the electrocatalytic processes. Ab initio techniques have been successful in providing insights in these electrocatalytic mechanisms, even motivating computational design of electrocatalysts. There remain, however, many open questions, thus motivating a call for fundamental studies of the adsorption processes on well-defined model surfaces. In this talk, I will present our recent results on a combined theory-experiment approach towards the understanding of iridium oxide catalysts for oxygen evolution reaction (OER), using well-defined surfaces grown using molecular-beam epitaxy and ab initio techniques. I will first discuss our study of SrIrO3 showing the challenge of the conventional potential-limiting-step approach in predicting the electrocatalytic activity in this system. In the second part, I will focus on IrO2 and how cyclic voltammetry curves on single-crystal can be used to understand adsorption energetics and benchmark the accuracy of ab initio approaches in electrocatalysis.