Hydrogen Production by Direct Lignin Electrolysis at Intermediate Temperatures

Hydrogen is produced conventionally by electrolyzing water or water vapor at onset voltages greater than 1 V, providing motivation for the development of more efficient electrolysis processes for a hydrogen economy. Numerous attempts have been made to use ethanol as a fuel for hydrogen production because this process reduces the electrolysis onset voltage significantly. However, ethanol feedstock from lignocellulose requires greater amounts of energy and results in higher production costs compared to those using starch as the feedstock. The current study describes direct lignin electrolysis at an onset voltage of ca. 0.25 V, with high current efficiencies of approximately 100% for hydrogen production at the cathode and approximately 85% for carbon dioxide production at the anode. Addition of H3PO4-impregnated lignin to the anode of a PtFe/C vertical bar Sn0.9In0.1P2O7 (150 mu m)vertical bar Pt/C cell enabled hydrogen production at a temperature of 150 degrees C.