Proton exchange membrane water electrolysis is limited by electrocatalyst dissolution at the anode during the oxygen evolution reaction (OER). Ruthenium and iridium oxides, while high-performing, degrade even at moderate cell potentials. This research investigates a quaternary Sn-Sb-Mo-W mixed oxide as a protective scaffold for ruthenium oxide. The acid-stable mixed oxide stabilizes ruthenium, resulting in lower degradation during OER compared to unprotected ruthenium oxide. This improved stability is attributed to the mixed oxide hindering the formation of reactive higher valence ruthenium (Ru⁸⁺).

Alexis Piñeiro-García, Xiuyu Wu, Mouna Rafei, Paul Jonathan Mörk, Eduardo Gracia-Espino