Facilitation of PdPb nanoalloy anchored on rGO/MOF-derived δ-Ga2O3 nanorod for electrocatalytic oxidation of methanol, ethanol and ethylene glycol

Abstract

A wrinkled rGO modified nanorod gallium oxides (Ga2O3) anchored PdPb nanoalloys composite (PdPb@rGO/Ga2O3) was prepared using GO/Ga-MOF as the precursor by facile hydrothermal, calcination and reduction approach, and then applied as an electrocatalyst for alcohols electrooxidation. Electrochemical tests show that the fabricated PdPb@rGO/Ga2O3 exhibits superior electrocatalytic activity and high anti-CO poisoning capability for methanol, ethanol and ethylene glycol oxidation reactions (MOR, EOR and EGOR), outperforming Pd@rGO/Ga2O3 and commercial Pd/C. Specifically, the bimetallic electrocatalyst owns the highest forward peak current density of 115.84 mA cm−2, 146.97 mA cm−2 and 226.59 mA cm−2, which is 4.69, 5.08 and 8.38 times of Pd/C for MOR, EOR and EGOR, respectively. After 3600 s CA test, the retained current density of PdPb@rGO/Ga2O3 achieves the initial 59.24%, 71.13% and 81.71% towards MOR, EOR and EGOR, respectively. The remarkable performance is attributed to the electronic effects of PdPb nanoalloys, which can improve the electronic structure of Pd d-band, while the surface decoration of Pb/PbO NPs can dramatically adsorb more oxy-species and accelerate the oxidative removal of CO(ads). Moreover, the oxidation mechanisms of three alcohols and the removal processes of CO(ads) on the Pd surface are analyzed in detail.