Atomically Dispersed Mn‐Doped Ru@RuO₂ Core/Shell Nanostructure with High Acidic Water Oxidation Performance Arising from Multiple Synergies

Abstract The high overpotential and unsatisfactory stability of RuO₂‐based catalysts seriously hinder their application in acidic oxygen evolution reaction (OER). Herein, a Ru@RuO₂ core/shell catalyst doped with atomically dispersed Mn species, denoted as Ru@Mn‐RuO₂, is reported, which is prepared by a facile one‐pot method. Detailed structural characterizations confirm that Mn is homogeneously and atomically distributed in RuO₂ shell, which causes lattice contraction of RuO₂. The as‐prepared Ru@Mn‐RuO₂ exhibits a very low overpotential of 190 mV at the current density of 10 mA cm⁻² and an excellent stability of 360 h, far surpassing the control samples Ru@RuO₂ without atomically dispersed Mn dopants and home‐made RuO₂ nanoparticles without metallic Ru core. With the further assistance of density functional theory calculations, the enhanced OER activity of Ru@Mn‐RuO₂ is attributed to multiple synergistic effects, including the MnO_x‐Ru (oxide shell) synergy, MnO_x‐Ru (metal core) synergy, and the Ru (core)‐RuO₂ (shell) synergy. Besides, the atomically dispersed Mn doping can increase the formation energy of soluble Ru cations, thus leading to the excellent stability of the Ru@Mn‐RuO₂ catalyst. This work shines light on the design of electrocatalysts with multiple synergistic effects towards efficient acid water splitting.