A CoV2O4 precatalyst for the oxygen evolution reaction: highlighting the importance of postmortem electrocatalyst characterization

Abstract

Vanadium-doped cobalt oxide materials have emerged as a promising class of catalysts for the oxygen evolution reaction. Previous studies suggest vanadium doping in crystalline Co spinel materials tunes the electronic structure and stabilizes surface intermediates. We report a CoV₂O₄ material that shows good activity for the oxygen evolution reaction. However, postmortem characterization of the catalyst material shows dissolution of vanadium resulting in an amorphous CoO_x material, suggesting that this vanadium-free material, and not CoV₂O₄, is the active catalyst. This study highlights the importance of postmortem characterization prior to mechanistic and computational analysis for this class of materials.