Integrating electrocatalytic hydrogen generation with selective oxidation of glycerol to formate over bifunctional nitrogen-doped carbon coated nickel-molybdenum-nitrogen nanowire arrays

Abstract

Abstract Achieving energy-efficient hydrogen production via hybrid water electrolysis systems requires not only a well-chosen alternative anodic reaction to replace the sluggish oxygen evolution reaction, but also highly efficient electrocatalysts. Herein, N-doped carbon coated Ni-Mo-N nanowire arrays supported on a nickel foam substrate (NC/Ni-Mo-N/NF) are constructed as a bifunctional electrocatalyst to facilitate electrocatalytic hydrogen production and selectively oxidize glycerol to formate simultaneously. With the desirable structural and compositional advantages of modified surface properties, optimized electronic structure, and Ni/Ni0.2Mo0.8N interfacial synergy effect, the resultant self-supported NC/Ni-Mo-N/NF electrode displays excellent electrocatalytic performance for both the hydrogen evolution reaction and glycerol oxidation reaction in alkaline conditions. Remarkably, the NC/Ni-Mo-N/NF||NC/Ni-Mo-N/NF two-electrode system needs only a cell voltage of 1.38 V at 10 mA cm−2 in 1 M KOH containing 0.1 M glycerol, much lower than that of conventional overall water splitting system (1.57 V at 10 mA cm−2).