Multi-porous NiAg-doped Pd alloy nanoparticles immobilized on reduced graphene oxide/CoMoO4 composites as a highly active electrocatalyst for direct alcohol fuel cell

A self-assembled reduced graphene oxide (rGO)/CoMoO4 supported Pd, PdNi, PdAg and PdNiAg electrocatalysts were synthesized via hydrothermal and in situ impregnation-reduction method to investigate their performance for methanol, ethanol and ethylene glycol (EG) electrooxidation in alkaline media. XRD, TEM, SEM, EDS, XPS and BET were used to characterize the structure, surface features, and porosity of the catalysts, respectively. Electrochemical measurement revealed that tri-metallic PdNiAg@rGO/CoMoO4 catalyst displays outstanding electrocatalytic activity, toxicity resistance, and durability comparing to mono-metallic Pd and bi-metallic PdNi, PdAg counterparts and commercial Pd/C. The excellent electrocatalytic activity has been successfully achieved thanks to NiAg-doped Pd alloy nanoparticles (NPs) owning more surface-active centers and strong synergistic effects, and the host of GO/CoMoO4 providing superior electron transfer performance and multi-porous for the ternary catalyst. Further electrocatalysis mechanism of three kinds of alcohol oxidation drew up a detailed analysis. The design, preparation, and prominent performance of these novel composites offer a conception and promising potential for application of electrocatalyst in direct alcohol fuel cells.