Optimizing the Electronic Structure of Ruthenium Oxide by Neodymium Doping for Enhanced Acidic Oxygen Evolution Catalysis

Abstract

It is a great challenge to design active and durable oxygen evolution reaction (OER) electrocatalysts for proton exchange membrane (PEM) electrolyzer due to the high dissolution of electrocatalysts in acidic solution. Herein, the Nd-doped RuO₂ (Nd_0.1RuO_x) is developed for enhanced oxygen evolution in 0.5 m H₂SO₄ solution with an overpotential of 211 mV to achieve 10 mA cm⁻². The theoretical calculation reveals that the improved activity of Nd_0.1RuO_x is due to the moderate decrease of d-band center energy, which balances the adsorption and desorption of oxygen intermediates. Moreover, the formation of more high valence state Ru⁴⁺ in Nd_0.1RuO_x is beneficial to the chemical stability of Ru species during the OER process, indicating that the introduction of Nd can effectively suppress the dissolution of Ru in acidic electrolytes. In addition, the PEM electrolyzer using Nd_0.1RuO_x/CC as the anode can be operated at 10 mA cm⁻² stably for 50 h. This study sheds new light on the design of the OER catalysts in acid by engineering the electronic structure of RuO₂.