Operando Surface X-Ray Diffraction Studies of Structurally-Defined Oxygen Evolution Electrocatalysts Based on Electrodeposited Epitaxial Transition Metal Oxide Films

摘要

Iron-group oxides are among the best precious-metal-free catalyst for the oxygen evolution reaction (OER) in alkaline media and thus of great interest for large-scale electrochemical water splitting into O_2 and H_2. A wide variety of different catalysts, based on oxides of Co, Fe, and Ni, have been synthesized and studied, exhibiting rather diverse nanoscale morphologies and usually an unknown surface structure. This makes it difficult to compare their reactivity and correlate it with ab initio theoretical studies, which hinders the development of clear structure-reactivity relationships and unambiguous determination of the OER reaction mechanism.