Porous Ni–Cu Alloy Dendrite Anode Catalysts with High Activity and Selectivity for Direct Borohydride Fuel Cells

A porous Ni–Cu alloy dendrite catalyst covered by Ni nanoparticles (Ni-np@NC) has been fabricated by an ultrafast and controllable strategy. The research results show that the morphology of the Ni–Cu alloy depends strongly on the Cu²⁺concentration. Moreover, the Ni-np@NC catalyst demonstrates excellent selectivity and activity toward the borohydride oxidation reaction (BOR). Furthermore, on the Ni-np@NC catalyst electrode, the overpotential merely requires 169 mV at a current density of 10 mA cm^–2 for BOR, and the fuel efficiency may reach 70%. The direct borohydride fuel cell using the Ni-np@NC/C anode can export a maximum power density of 218 mW cm^–2, much higher than that using the noble-based anode reported in the literature. The remarkable enhancement of Ni-np@NC catalyst performances is on the back of the unique morphology of porous dendrite covered by nanoparticles and the introduction of Cu.