Tuning electronic structure of RuO2 by single atom Zn and oxygen vacancies to boost oxygen evolution reaction in acidic medium

The poor stability of RuO₂ electrocatalysts has been the primary obstacles for their practical application in polymer electrolyte membrane electrolyzers. To dramatically enhance the durability of RuO₂ to construct activity-stability trade-off model is full of significance but challenging. Herein, a single atom Zn stabilized RuO₂ with enriched oxygen vacancies (SA Zn-RuO₂) is developed as a promising alternative to iridium oxide for acidic oxygen evolution reaction (OER). Compared with commercial RuO₂, the enhanced Ru–O bond strength of SA Zn-RuO₂ by forming Zn-O-Ru local structure motif is favorable to stabilize surface Ru, while the electrons transferred from Zn single atoms to adjacent Ru atoms protects the Ru active sites from overoxidation. Simultaneously, the optimized surrounding electronic structure of Ru sites in SA Zn-RuO₂ decreases the adsorption energies of OER intermediates to reduce the reaction barrier. As a result, the representative SA Zn-RuO₂ exhibits a low overpotential of 210 mV to achieve 10 mA cm⁻² and a greatly enhanced durability than commercial RuO₂. This work provides a promising dual-engineering strategy by coupling single atom doping and vacancy for the tradeoff of high activity and catalytic stability toward acidic OER.