Electrochemical disproportionation strategy to in-situ fill cation vacancies with Ru single atoms

Supported single-atom catalysts (SACs) possess high catalytic activity, selectivity, and atom utilizations. However, the atom coordination environments of SACs are difficult to accurately regulate due to the high complexity of coordination site and local environment of support. Herein, we develop an in-situ electrochemical cation-exchange method to fill the cation vacancies in MnO2 with Ru single atoms (SAs). This obtained catalyst exhibits high mass activity, which is similar to 44 times higher than commercial RuO2 catalyst and excellent stability, superior to the most state-of-the-art oxygen evolution reaction (OER) catalysts. The experimental and theoretical results confirm that the doped Ru can induce charge density redistribution, resulting in the optimized binding of oxygen species, and the strong covalent interaction between Ru and MnO2 for resisting oxidation and corrosion. This work will provide a new concept in the synthesis of well-defined local environments of supported SAs.