RuO2-PdO nanowire networks with rich interfaces and defects supported on carbon toward the efficient alkaline hydrogen oxidation reaction

Abstract

Interfacial engineering is a promising approach for enhancing electrochemical performance, but rich and efficient interfacial active sites remain a challenge in fabrication. Herein, RuO2-PdO heterostructure nanowire networks (NWs) with rich interfaces and defects supported on carbon (RuO2-PdO NWs/C) for alkaline hydrogen oxidation reaction (HOR) was formed by a seed induction-oriented attachment-thermal treatment method for the first time. As expected, the RuO2-PdO NWs/C (72.8% Ru atomic content in metal) exhibits an excellent activity in alkaline HOR with a mass specific exchange current density (j0,m) of 1061 A gRuPd−1, which is 3.1 times of commercial Pt/C and better than most of the reported non-Pt noble metal HOR electrocatalysts. Even at the high potential (∼0.5 V vs. RHE) or the presence of CO (5 vol%), the RuO2-PdO NWs/C still effectively catalyzes the alkaline HOR. Structure/electrochemical analysis and theoretical calculations reveal that the interfaces between RuO2 and PdO act as the active sites. The electronic interactions between the two species and the rich defects for the interfacial active sites weaken the adsorption of Had, also strengthen the adsorption of OHad, and accelerate the alkaline HOR process. Moreover, OHad on RuO2 can spillover to the interfaces, keeping the RuO2-PdO NWs/C with the stable current density at higher potential and high resistance to CO poisoning.