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 Ni^III 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 Formula Presented 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 Formula Presented 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.