Carbon-Supported IrCoO nanoparticles as an efficient and stable OER electrocatalyst for practicable CO2 electrolysis

Abstract The development of an efficient and stable oxygen evolution reaction (OER) electrocatalyst operating under pH-neutral conditions is vital for the realization of sustainable CO2 reduction reaction (CO2RR) systems in the future. For commercializing this system, it is also important to be able to use general-purpose water as an electrolyte. Here, we explore, characterize and validate a new IrCoOx mixed metal oxide as efficient and stable OER catalyst, before we investigate and proof its suitability as counter electrode to a CO2RR cathode operating under pH-neutral conditions. More specifically, carbon-supported IrCoOx core-shell nanoparticles exhibited a highly efficient OER catalytic activity and stability compared to state-of-art reference IrOx catalysts in CO2-saturated 0.5 M KHCO3 tap-water. IrCoOx/C also exhibited a significantly improved electrochemical oxidation and corrosion resistance than IrOx, resulting in a beneficial suppression of Ir dissolution. The application of IrCoOx/C in the CO2 electrolyzer displayed superior CO space-time yields over prolonged electrolyzer tests.