Le Chatelier’s principle to stabilize intrinsic surface structure of oxygen-evolving catalyst for enabling ultra-high catalytic stability of zinc-air battery and water splitting

Abstract

Well-designed highly active intrinsic surface structure of a catalyst for oxygen evolution reaction (OER) often faces the problem of corrosion dissolution, which severely deteriorates its catalytic stability, and breaking this activity-stability trade-off has always been a huge and long-term challenge. Herein, we employ Le Chatelier’s principle to address this dissolution problem of the catalyst to maintain its intrinsic surface structure for highly efficient and ultra-stable OER. Taking highly active but susceptible oxygen vacancy-rich Co-W oxide as the model catalyst for alkaline OER, its dissolving kinetics is significantly passivated by introducing homo ions into the electrolyte to regulate the dissolution equilibrium, thus achieving ultralong operating stability without sacrificing its high activity. The theoretical calculations and in-situ experimental results unravel the underlying mechanism of this strategy, that is, the homo ions (tungstate ions) can be preferentially adsorbed on the catalyst surface to construct a local non-corrosive environment, thus effectively stabilizing the well-designed unsaturated active cobalt sites to maintain the intrinsic surface structure of the catalyst and preventing them from being reconstructed or transformed toward the unfavorable direction. Importantly, this strategy is also effective in zinc-air battery and electrolytic water splitting, achieving ultra-stable performance over 1200 h, which is of great importance for promoting the practical applications of low-cost non-noble metal-based catalysts in energy devices.