In Situ Immobilizing Atomically Dispersed Ru on Oxygen-Defective Co<sub>3</sub>O<sub>4</sub> for Efficient Oxygen Evolution
Cheng‐Zong Yuan, Shuo Wang, Kwan San Hui, Kaixi Wang, Junfeng Li, Haixing Gao, Chenyang Zha, Xiaomeng Zhang, Duc Anh Dinh, Xi‐Lin Wu, Zikang Tang, Jiawei Wan, Zongping Shao, Kwun Nam Hui
Abstract
The synergistic regulation of the electronic structures of transition-metal oxide-based catalysts via oxygen vacancy defects and single-atom doping is efficient to boost their oxygen evolution reaction (OER) performance, which remains challenging due to complex synthetic procedures. Herein, a facile defect-induced in situ single-atom deposition strategy is developed to anchor atomically dispersed Ru single-atom onto oxygen vacancy-rich cobalt oxides (Ru/Co 3 O 4– x ) based on the spontaneous redox reaction between Ru 3+ ions and nonstoichiometric Co 3 O 4– x . Accordingly, the as-prepared Ru/Co 3 O 4– x electrocatalyst with the coexistence of oxygen vacancies and Ru atoms exhibits excellent performances toward OER with a low overpotential of 280 mV at 10 mA cm –2, a small Tafel slope value of 86.9 mV dec –1, and good long-term stability in alkaline media. Furthermore, density functional theory calculations uncover that oxygen vacancy and atomically dispersed Ru could synergistically tailor electron decentralization and d-band center of Co atoms, further optimizing the adsorption of oxygen-based intermediates (*OH, *O, and *OOH) and reducing the reaction barriers of OER. This work proposes an available strategy for constructing electrocatalysts with abundant oxygen vacancies and atomically dispersed noble metal and presents a deep understanding of synergistic electronic engineering of transition-metal-based catalysts to boost oxygen evolution.