High-Performance Zero-Gap Glycerol-Fed Electrolyzer for C₃ Chemicals and Hydrogen Production

Area of Science:

• Electrochemistry
• Catalysis
• Biomass Valorization

Background:

• Electrochemical oxidation of biomass-derived glycerol is a promising low-voltage alternative to water oxidation for co-producing hydrogen and valuable chemicals.
• High current densities (>300 mA cm⁻²) are challenging for platinum-based catalysts due to rapid deactivation.

Purpose of the Study:

• To develop a stable, high-performance anode for electrochemical glycerol oxidation at industrially relevant rates.
• To achieve efficient co-production of hydrogen and C3 chemicals from glycerol at low cell voltages.

Main Methods:

• Fabrication of a membrane electrode assembly (MEA) with a platinum-decorated nickel foam (Pt/NiF) anode.
• Sustained electrochemical testing at high current densities (500 mA cm⁻²).
• In situ impedance spectroscopy and systematic variation of electrolyte composition and temperature.

Main Results:

• The Pt/NiF anode sustained operation for 24 hours at 500 mA cm⁻² with a low average cell voltage of 1.21 V.
• Achieved >88% selectivity toward C3 products, with a partial current density of 227 mA cm⁻² for lactic acid.
• Identified optimized operating conditions (1.2-1.4 V, 55-65°C) and elucidated reaction mechanisms.

Conclusions:

• The Pt/NiF anode establishes new benchmarks for efficient, low-voltage electrochemical valorization of biomass-derived polyols.
• Demonstrated sustained co-generation of hydrogen (∼175 mmol) and C3 products (45 mmol) per 24h cycle.
• The developed system offers a viable pathway for industrial-scale biomass conversion at relevant rates.