Constructing Adjustable Heterointerface for Enhancing Acidic Oxygen Evolution Performances of RuO₂@CoMnO₃ Nanosheets Electrocatalysts

Developing ruthenium-based (Ru-based) catalysts with a heterointerface is essential to improving the acidic oxygen evolution reaction (OER) performance. In this study, we first prepared RuO 2 /CoMnO 3 nanosheet catalysts by solid-phase pyrolysis, featuring a low Ru content, and presented a high OER mass activity (1742.9 A g Ru –1 at 1.53 V) and superior stability (500 h at 10 mA cm –2 ) in 0.5 M H 2 SO 4 under a three-electrode system. Notably, Co and Mn sites facilitated electron transfer to Ru sites through bridge oxygen to avoid Ru overoxidation, as proved by the increase in the average surface oxidation state (SOS) of Mn and Co and the insignificant change in the average SOS of Ru after the chronopotentiometry test. Moreover, the heterointerface can reduce the OER energy barrier and restrain the participation of lattice oxygen. This work indicates the significant potential of employing well-supported catalysts with an adjustable heterointerface to prominently improve the activity and stability of Ru-based catalysts.