Enhancing the Stability of Ruthenium Dioxide for Acidic Oxygen Evolution Reaction via Trapping Two‐Coordinated Oxygen

ABSTRACT While great progress has been made in enhancing the stability of RuO 2 ‐based electrocatalysts for acid oxygen evolution reaction (OER) by suppressing lattice oxygen‐mediated (LOM) pathway, the oxygen sites that genuinely participate in the LOM pathway still remain unclear. Herein, through systematic density functional theory (DFT) calculations, we demonstrate that surface two‐coordinated oxygen (O 2c ) sites in RuO 2 (i.e., with a low vacancy formation energy) can easily release from the lattice to participate in the LOM, whereas three‐coordinated counterparts (O 3c ) (i.e., with a high formation energy) are kinetically inert toward the LOM. To this end, we attempt to enhance the vacancy formation energy of O 2c and thus suppress the LOM via the introduction of asymmetric Ru−O−M covalent bond configurations (M denotes metal dopants of Sc, Cr, V, Ti, and Mn). It is found that the Ru−O−V configuration exhibits a higher O 2c vacancy formation energy than other configuration, and thus V‐doped RuO 2 can significantly suppress the LOM for enhancing the acid OER stability. The above findings open up novel pathways to improve the long‐term stability of RuO 2 ‐based electrocatalysts for acid OER through the rational stabilization of surface O 2c sites.