Hierarchical leaf-shaped Ni@Zn bimetallic catalyst with high stability and selectivity for borohydride oxidation

The bimetallic nickel zinc catalyst (Ni@Zn) with hierarchical morphology has been fabricated successfully by an ultrafast and simple synthesis strategy. Unique hierarchical morphology of the catalyst composes of honeycomb arrays, which are formed by Ni shell/Zn core leaves. This Ni@Zn possesses excellent catalytic activity, stability, and selectivity towards borohydride oxidation reaction (BOR). Moreover, a direct borohydride fuel cell (DBFC) with the Ni@Zn/C anode delivers a peak power density of 180.3 mW cm-2 at 298 K. The outstanding performances originate from the increase of electroactive surface area, enhancement of reactants adsorption, and the inhibition of Ni oxidation, which are attributed to its unique hierarchical structure and the introduction of Zn. This study may provide important inspiration for developing efficient noble-metal-free catalysts for DBFC.