Bifunctional MnCoP Electrocatalytic Nanospheres for Selective Electrooxidation of Benzyl Alcohol Coupled with Hydrogen Evolution

Abstract Replacing the sluggish oxygen evolution reaction with value-added organic electrooxidation offers an effective strategy to reduce the energy consumption of water electrolysis while simultaneously producing industrially important chemicals. This work reports a bimetallic MnCoP electrocatalyst for the hydrogen evolution reaction and benzyl alcohol oxidation reaction in alkaline media. The catalyst exhibits an HER Tafel slope of 117 mV dec−1 and enhanced anodic kinetics toward BAOR. For benzyl alcohol oxidation, MnCoP requires potentials of only 1.27 V vs RHE to deliver current densities of 10 mA cm−2, with a Tafel slope of 80 mV dec−1. At 1.425 V versus RHE, the catalyst shows ∼100% benzyl alcohol conversion and benzoic acid selectivity with a Faradaic efficiency of ∼99.4%. Time-dependent 1H NMR and HPLC analyses establish a sequential oxidation pathway in which benzyl alcohol is initially converted to benzaldehyde, followed by further oxidation to benzoic acid. The catalyst also maintains its performance up to 20 cycles and displays broad applicability toward other substituted aromatic alcohols. Finally, a MnCoP||MnCoP electrolyser was fabricated, which enables simultaneous benzyl alcohol oxidation and hydrogen evolution at a lower cell voltage (1.5 V vs RHE) than conventional water splitting. These results establish MnCoP as a versatile bifunctional electrocatalyst for integrating energy-efficient hydrogen production with value-added organic electrosynthesis.