Direct electrolysis of waste newspaper for sustainable hydrogen production: an oxygen-functionalized porous carbon anode

Biomass electrolysis enables hydrogen (H-2) production at onset voltages of less than 1 V, depending on the fuel species. However, biofuel derived from biomass not categorized as food and produced from environmentally friendly processes is needed for the development of sustainable strategies. In addition, the biofuel should not require special and expensive procedures for processing. The present report describes the direct electrolysis of waste newspaper for H-2 production. Cellulose and lignin included in the newspaper were subject to dissolution and hydrolysis in a phosphoric acid solvent at the anode in a temperature range of 100-175 degrees C. The resulting decomposition products were electrolyzed to H-2 and carbon dioxide (CO2), at low onset voltages (ca. 0.2 V) and high current efficiencies (H-2: 1.0, CO2: 0.9). Carbon black functionalized with carbonyl groups showed greater catalytic activity than a PVC catalyst for the anode reaction. H-2 yield reached ca. 0.2 g per 1 g of newspaper in a batch cell. H-2 was produced continuously in a current-density range of 0.15-0.25 A cm(-2) while maintaining plateau-like voltage behavior in a flow cell. The energy consumed for electrolysis at a current density of 0.15 A cm(-2) was as low as 1.27 kWh (Nm(3))(-1).