Modulation of the electronic structure of AuIr alloy anchor on vacancy–deficient Nb2O5-x as OER electrocatalyst for PEM water electrolysis

The development of highly active and stable catalysts of oxygen evolution reaction (OER) plays a crucial role in proton-exchange-membrane water electrolysis (PEMWE). Herein, an electronic modulate was used to fabricate oxygen defect-rich and supported metal catalysts AuIr/Nb 2 O 5-x , and it promoted the sluggish kinetics and low efficiencies of OER with the interaction between oxygen defects and the active sites. The Nb–O defect with an electron redistribution and manipulated active electronic state tailored the OER performance. The Ir actively exposed the AuIr/Nb 2 O 5-x -500 catalyst, which exhibited a low overpotential of 230 mV and maintained an excellent stability for 200 h at the current density of 10 mA cm −2 in 0.5 M H 2 SO 4 electrolyte. Furthermore, the PEMWE using AuIr/Nb 2 O 5-x -500 as the anode revealed a high water-splitting performance (1.61 V @ 0.5 A cm −2 & 1.70 V @ 1 A cm −2 ). In-situ Raman spectra and theoretical calculations revealed the electronic structure of AuIr/Nb 2 O 5-x -500 and the mechanism of OER processes, which rationalized the improved performance through the synergistic effect of metal–support interaction and defect effect.