Interfacial engineering of Ru–RuSb2 for enhanced activity and stability towards alkaline hydrogen oxidation reaction

Abstract

Although Ru has been regarded as the key candidate to replace Pt in alkaline hydrogen oxidation reaction (HOR), the substandard stability owing to its easy oxidation seriously impacts its practical application. In this work, we report the construction of a Ru–RuSb₂ heterostructure, showing excellent performance and stability towards alkaline HOR. Owing to the difference in the work functions of Ru and RuSb₂, the charge transfer induced by the build-in electric field modifies the electron distribution on the surface, enhancing the OH adsorption on the heterostructure. Moreover, the connectivity of the hydrogen bonding network is promoted with the inducing of OH species, which thereby leads to elevated proton transfer and accelerated HOR process, presenting a mass activity (j^k,m) of 2.098 mA μg⁻¹ at 50 mV, which is 6-fold and 20-fold higher than those of Pt/C_com and Ru/NC, respectively. Owing to the change of the OH adsorption sites on Sb and the rapid HOR process on the surface, the pace of the oxidation on Ru of the heterostructure during the reaction largely slows down, contributing to the outstanding stability with only 2.59% decline in the activity.