Redox-manipulated RhO nanoclusters uniformly anchored on SrFeRhMoO perovskite for CO electrolysis.

The sluggish reaction kinetics of CO electroreduction in perovskite-based cathodes severely limits the efficiency of solid oxide electrolysis cells (SOECs). The construction of the high-density active sites on the perovskite surface is crucial for promoting CO electrolysis in SOEC. In this study, we explore a redox-induced redispersion strategy to produce RhO nanoclusters uniformly anchored on a SrFeRhMoO (SFRhM) perovskite surface with a high density of 36,000 µm. Compared with non-uniformly distributed RhO nanoparticles on SrFeMoO (RhO /SFM) prepared by a conventional impregnation process, the successive reduction and oxidation treatment first exsolves the highly dispersed RhFe alloy nanoparticles on SFRhM and then selectively dissolves the iron species in the RhFe alloy nanoparticles into the bulk of SFRhM, resulting in fully exposed RhO nanoclusters uniformly anchored on the SFRhM surface (RhO @SFRhM). Electrochemical measurements and density functional theory calculations indicate that the high-density RhO @SFRhM interfaces promote CO adsorption and activation during CO electrolysis, thus leading to improved electrocatalytic activity and stability compared to that of its SFRhM and RhO /SFM counterparts.