Nickel Promoted Palladium Nanoparticles for Electrocatalysis of Carbohydrazide Oxidation Reaction.

Carbohydrazide is a potential alternative to toxic hydrazine for fuel cell applications to overcome the challenges of storage and transportation of hydrogen. In this work, Ni-alloyed Pd nanoparticles (NPs) with varied Pd-Ni ratios supported on carbon black (PdNix/C) are prepared and their catalytic performance for the carbohydrazide electro-oxidation reaction is investigated. The catalytic performance of PdNix/C NPs is significantly improved in comparison to Pd/C NPs. The current density of PdNix/C NPs with optimized Pd-Ni atom ratio can reach 3.26 A mg(metal)(-1) at a potential of 0.4 V (vs reversible hydrogen electrode), which is an increase of 2.4 times compared to that of Pd/C. The density functional theory calculation indicates the enhanced catalytic activity is caused by the change of adsorption energy of carbohydrazide molecules on the metal surface. It exhibits a volcano relationship between the adsorption energy and the catalytic current density of PdNix/C with varied Pd-Ni atom ratios.