Metal-atom-doped W18O49 nanowires for electrocatalytic oxygen evolution reaction in alkaline medium

Abstract

Non-noble transition metal oxides (TMOs) are promising catalysts with improved catalytic activity and stability in oxygen evolution reaction (OER). However, the structural complexity of TMO-based electrocatalysts renders the determination of the active sites and OER mechanisms challenging. Here, we demonstrate that the OER activity of Co-doped one-dimensional W₁₈O₄₉ (Co-W₁₈O₄₉) is intrinsically dominated by the surface structure and electronic properties of the octahedral sites and Co–O–W bonds. Compared with RuO₂ and W₁₈O₄₉ heterogeneous electrocatalysts, Co-W₁₈O₄₉ exhibits higher turnover frequency, attaining 1.97 s⁻¹ at 500 mV overpotential. The results indicate that Co substitution contributes to the localized charge distribution of the active octahedral sites constructed by the Co–O–W bonds under OER conditions. Here, we determine the mechanism of TMOs for the OER, which may be applied to various other TMOs for OER electrocatalyst design.