Interfacial Engineering of Ni/V2 O3 Heterostructure Catalyst for Boosting Hydrogen Oxidation Reaction in Alkaline Electrolytes.

ABSTRACT

Alkaline fuel cells can permit the adoption of platinum group metal-free (PGM-free) catalysts and cheap bipolar plates, thus further lowering the cost. With the exploration of PGM-free hydrogen oxidation reaction (HOR) catalysts, nickel-based compounds have been considered as the most promising HOR catalysts in alkali. Here we report an interfacial engineering through the formation of nickel-vanadium oxide (Ni/V2 O3 ) heterostructures to activate Ni for efficient HOR catalysis in alkali. The strong electron transfer from Ni to V2 O3 could modulate the electronic structure of Ni sites. The optimal Ni/V2 O3 catalyst exhibits a high intrinsic activity of 0.038 mA cm-2 and outstanding stability. Experimental and theoretical studies reveal that Ni/V2 O3 interface as the active sites can enable to optimize the hydrogen and hydroxyl bindings, as well as protect metallic Ni from extensive oxidation, thus achieving the notable activity and durability.