A Facile <i>In Situ</i> Synthesis of Carbon Supported Nickel Phosphide (Ni<sub>5</sub>P<sub>4</sub>@C) and Application as Hydrogen Oxidation Reaction Catalyst in Alkaline Electrolyte

Monodisperse nickel phosphide (Ni 5 P 4 ) nanoparticles supported on carbon (Ni 5 P 4 @C) were in situ synthesized by one step solution-phase route, in which the mixture of trioctyloxide (TOPO) and trioctylphosphine (TOP) was used as solvent, capping agent and phosphor source. Ni 5 P 4 nanocrystals were in situ coupled by active carbon simply adding the carbon to the reaction solution. The as-prepared Pt-free Ni 5 P 4 nanocrystals exhibit the enhanced electrocatalytic activity toward hydrogen oxidation reaction (HOR) compared to pure commercial Ni nanoparticles. Therefore, the obtained Ni 5 P 4 @C nanocatalyst appears to be promising non precious metal electrocatalysts for HOR.