High‐Performance Zero‐Gap Glycerol‐Fed Electrolyzer for C ₃ Chemicals and Hydrogen Production

Abstract

ABSTRACT The electrochemical oxidation of biomass‐derived glycerol offers a promising low‐voltage alternative to water oxidation in electrolyzers, enabling the co‐production of hydrogen and value‐added chemicals. However, achieving high conversion rates at current densities above 300 mA cm −2 remains challenging due to the rapid deactivation of platinum‐based catalysts. Here, we present a membrane electrode assembly (MEA) featuring a platinum‐decorated nickel foam (Pt/NiF) anode that sustains operation for 24 h at 500 mA cm −2 with an average cell voltage of just 1.21 V, outperforming all previously reported glycerol‐fed electrolyzers operating below 1.5 V. The system exhibits >88% selectivity toward C3 products, achieving 227 mA cm −2 partial current density for lactic acid and 9% single‐pass glycerol conversion. In situ impedance spectroscopy identifies voltage‐dependent regimes linked to platinum hydroxide formation, glycerol oxidation, and oxygen evolution. Systematic variation of electrolyte composition and temperature reveals an optimized window (1.2–1.4 V, 55–65°C) for sustained performance. Under these conditions, a single 24 h cycle co‐generates ∼175 mmol of H 2 and 45 mmol of C3 products. These results establish new operational and mechanistic benchmarks for efficient, low‐voltage electrochemical valorization of biomass‐derived polyols at industrially relevant rates.