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

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