Selective Facet Engineering of Ni12P5 Nanoparticle for Maximization of Electrocatalytic Oxidative Reaction of Biomass Chemicals

Electrocatalytic hydrogen generation is a prime research topic for the large-scale production of hydrogen fuel. High energy demanding oxygen evolution process impedes the production of H2 at low potentials. Conversion of biomass to value-added chemicals or fuels is appraised as an upcycling process, which is advantageous for resource management. Coupling of hydrogen generation at the cathode with oxidative conversion of biomass to market-demanded chemicals at the anode is a sustainable approach to increase energy efficiency in hybrid electrolysis. For that purpose, Ni-based anode electrocatalysts are in the forefront for ease of formation of hypervalent NiIII species, at a mild anodic potential, which act as an oxidant to propagate the oxidation and dehydrogenation reactions. Herein, we synthesized Ni12P5 nanohexagon via kinetic stabilization of high index { 4 25 ̅ } facets and compared the electrocatalytic activity toward various biomass-derived platform chemicals oxidation with the thermodynamically stable Ni12P5 nanosphere. The Ni12P5 nanohexagon outperforms the current state-of-the-art catalysts regarding mass activity, product conversion, and Faradaic yield. Ease of formation of active species, faster charge transfer, and enhanced adsorption of substrates over { 4 25 ̅ } facets resulted in this superior activity. This shape-directing effects on Ni12P5 ensured potential advantage of 150 mV in hybrid electrolysis over water splitting reaction when ethanol was used as a substrate in a two-electrode electrolyzer cell.