Structural and chemical mapping of Au-Co(OH)2 electrocatalytic films shows the formation of ordered Au crystallites and the suppression of Co oxidation

Abstract

Transition metal oxide catalysts typically reconstruct both chemically and structurally during the oxygen evolution reaction (OER). Here we simultaneously map the changes in both the crystallinity and chemistry of an Au-Co(OH)2 film after the OER with X-ray diffraction and X-ray absorption spectroscopy imaging. This correlated analysis shows that Au inhibits the oxidation of Co and forms crystallographically ordered clusters of Au nanoparticles, enabling better catalytic activity.