Simultaneous H2 Generation and Biomass Upgrading in Water by an Efficient Noble-Metal-Free Bifunctional Electrocatalyst

As an environmentally friendly approach to generate H-2, electrocatalytic water splitting has attracted worldwide interest. However, its broad employment has been inhibited by costly catalysts and low energy conversion efficiency, mainly due to the sluggish anodic half reaction, the O-2 evolution reaction (OER), whose product O-2 is not of significant value. Herein, we report an efficient strategy to replace OER with a thermodynamically more favorable reaction, the oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA), catalyzed by 3D Ni2P nanoparticle arrays on nickel foam (Ni(2)PNPA/NF). HMF is one of the primary dehydration intermediates of raw biomass and FDCA is of many industrial applications. As a bifunctional electrocatalyst, Ni(2)PNPA/NF is not only active for HMF oxidation but also competent for H-2 evolution. In fact, a two-electrode electrolyzer employing Ni2P NPA/NF for simultaneous H-2 and FDCA production required a voltage at least 200 mV smaller compared with pure water splitting to achieve the same current density, as well as exhibiting robust stability and nearly unity Faradaic efficiencies.