RuO2 with Short-Range Ordered Tantalum Single Atoms for Enhanced Acidic Oxygen Evolution Reaction

Abstract

Ruthenium Dioxide (RuO2), as one of the most promising alternatives to IrO2, suffers from the severe dissolution and overoxidation of Ru active sites during the acidic oxygen evolution reaction (OER), which hinders its practical application. Herein, the study constructs a short-range ordered tantalum single atoms-doped RuO2 catalyst (Ta-RuO2) with asymmetric Ru-O-Ta(-O-Ta) active units for the enhanced acidic OER. The Ta-RuO2 catalyst exhibits superior catalytic activity with an overpotential of 201 mV at 10 mA cm(-2) and a long-lasting stability of 280 h. Physical characterizations combined with electrochemical tests reveal that the incorporation of atomically arranged Ta atoms induces significant tensile strain, effectively optimizing the adsorption strength of oxygen-containing intermediates by regulating the Ru d-band center and weakening the Ru-O covalency, thus boosting the catalytic activity. Furthermore, the formed Ru-O-Ta(-O-Ta) active local structure is well maintained during the OER process owing to the synergy of strong corrosion resistance of Ta-O bonds and the electron transfers from Ta to Ru via oxygen bridge stabilizing the Ru sites, contributing to the enhanced stability. This study provides a novel method via incorporation of corrosion-resistant and short-range ordered single atoms to significantly enhance the acidic OER stability and activity of cost-effective catalysts.