Revisiting the degradation mechanism of ruthenium oxide for oxygen evolution reaction in acidic media

The anode of a proton-exchange membrane-based electrolyzer presently necessitates the utilization of iridium oxide (IrO2) as an anodic catalyst, which is exceedingly costly and scarce on Earth. Ruthenium oxide (RuO2) has garnered significant attention due to its superior catalytic activity and lower cost compared to IrO2. However, the relatively inadequate stability of RuO2 impedes its practical application. The deterioration of RuO2 is presently ascribed to the dissolution of Ru sites. Through systematic investigations encompassing distribution of relaxation times analysis, leaching measurements, structural characterizations, and designed experiments, we verify that the deactivation of RuO2 is primarily attributed to the surface reconstruction of the catalyst to insert phase, rather than dissolution. (c) 2024 Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.