Hydrogen Production by Direct Lignin Electrolysis at Intermediate Temperatures

5 years ago

Hydrogen Production by Direct Lignin Electrolysis at Intermediate Temperatures

Kazuyo Kobayashi, Masahiro Nagao, Takashi Hibino, Shinya Teranishi

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|Sn0.9In0.1P2O7 (150 μm)|Pt/C cell enabled hydrogen production at a temperature of 150 °C. Lignin was electrolyzed directly to hydrogen and carbon dioxide between 100 and 200 °C. In particular, addition of H3PO4-impregnated lignin to the anode of a PtFe/C||Pt/C cell operating at 150 °C enabled hydrogen production at an onset voltage of circa 0.25 V, offering the possibility of significant savings in the energy required for producing hydrogen.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/celc.201700917