In Situ Modulation of NiFeOOH Coordination Environment for Enhanced Electrocatalytic-Conversion of Glucose and Energy-Efficient Hydrogen Production

Glucose electrocatalytic-conversion reaction (GCR) is a promising anode reaction to replace the slow oxygen evolution reaction (OER), thus promoting the development of hydrogen production by electrochemical water splitting. Herein, NiFe-based metal-organic framework (MOF) is used as a precursor to prepare W-doped nickel-iron phosphide (W-NiFeP) nanosheet arrays by ion exchange and phosphorylation, which exhibit a high electrocatalytic activity toward the hydrogen evolution reaction (HER), featuring an overpotential of only −179 mV to achieve the current density of 100 mA cm −2 in alkaline media. Notably, electrochemical activation of W-NiFeP facilitates the in situ formation of phosphate groups producing W,P-NiFeOOH, which, in conjunction with the W co-doped amorphous layers, leads to a high electrocatalytic performance toward GCR, due to enhanced proton transfer and adsorption of reaction intermediates, as confirmed in experimental and theoretical studies. Thus, the two-electrode electrolyzer of the W-NiFeP/NF||W,P-NiFeOOH/NF for HER||GCR needs only a low cell voltage of 1.56 V to deliver 100 mA cm −2 at a remarkable hydrogen production efficiency of 1.86 mmol h −1 , with a high glucose conversion (98.0%) and formic acid yields (85.2%). Results from this work highlight the significance of the development of effective electrocatalysts for biomass electrocatalytic-conversion in the construction of high-efficiency electrolyzers for green hydrogen production.