Operando-Induced Surface Reconstruction of NiSe2 for Efficient Glycerol Electrooxidation toward Enhanced Hydrogen Production

Glycerol electrooxidation (GEOR) is a compelling alternative to the oxygen evolution reaction (OER) in water electrolysis, lowering energy demand while simultaneously producing valuable chemicals. However, efficient and selective catalysts for GEOR remain limited, and a significant gap exists between laboratory research and industrial application. In this study, Ni-based chalcogenides and pnictogenides (NiXy, X = O, S, P, Se) were synthesized to investigate the role of heteroatoms in active-site formation and GEOR selectivity. Among the materials studied, NiSe2 exhibited the best GEOR activity, delivering 100 mA cm–2 at 1.45 VRHE while achieving ≈100% Faradaic efficiency (FEGEOR), with 95% selectivity toward formate. In situ spectroscopy, diffraction analysis, and first-principles calculations reveal that this improved performance originates from rapid γ-NiOOH formation and optimized glycerol adsorption energy. This work reports a dry-cathode zero-gap GEOR-HER electrolyzer successfully operating under industrially relevant conditions (i.e., 400 mA cm–2 at 60 °C), achieving nearly unity FEGEOR at 1.7 V with complete suppression of OER, highlighting GEOR-HER potential to enhance both energy efficiency and economic viability of electrolytic hydrogen production.