Pd Nanoparticles Coupled to NiMoO₄-C Nanorods for Enhanced Electrocatalytic Ethanol Oxidation

The interfacial interaction including chemical bonding or electron transfer and even physisorption in composite electrocatalysts has a considerable effect on electrocatalytic oxidation reaction. Herein, we report a tremendously enhanced catalytic activity and excellent durability for the ethanol electro-oxidation reaction in NiMoO₄-C-supported Pd composites (Pd/NiMoO₄-C) compared to the commercial Pd/C (10%) catalyst. The X-ray powder diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy measurements disclose that the strong electron transfer between NiMoO₄ nanorods and Pd nanoparticles likely induces the formation of more electrochemical active centers and improves the adsorption-desorption capacity of reactants and corresponding intermediates. In addition, the Pd/NiMoO₄-C composite exhibits superior specific activity for ethanol oxidation compared to the Pd/NiMoO₄ catalyst with physically incorporated carbon black, which further reveals that the stronger anchoring effect between Pd and C and higher electrical conductivity in Pd/NiMoO₄-C composites are also conducive to promote the ethanol oxidation reaction. These discoveries provide an effective and simple method for the design of advanced electrocatalysts and provide more insights into optimizing the electronic interaction between the catalyst and support in general.