Bimetallic Doped RuO₂ with Manganese and Iron as Electrocatalysts for Favorable Oxygen Evolution Reaction Performance

Synthesizing oxygen evolution reaction (OER) catalysts with enhanced activity by codoping has been proven to be a feasible approach for the efficient use of noble metals via renewing their basic intrinsic properties. In continuation of the research in codoping, we prepare a ruthenium-based bimetallic doped catalyst Mn_xFe_yRu_1–x–yO₂ with an outstanding OER activity as compared to pure RuO₂, one of the state-of-the-art OER catalysts. The synthesized codoped RuO₂ with a Mn/Fe molar ratio of 1 reflected a Tafel slope of only 41 mV dec^–1, which is appreciably lower than 64 mV dec^–1 for pure RuO₂. The X-ray photoelectron spectroscopy (XPS) performed reveals that oxygen vacancy and manganese valency are the key factors of the OER activity for codoped catalysts.