Hydrogen Evolution from Native Biomass with Fe3+/Fe2+ Redox Couple Catalyzed Electrolysis.

A low energy electrolysis process that directly converts native biomasses to hydrogen at low temperature was reported. Practically, an environmentally-friendly proton exchange membrane electrolysis cell (PEMEC) uses a simple redox ion pair, Fe 3+ /Fe 2+ , as the catalyst which functions as an oxidation agent (oxidizing biomass), charge carrier (transferring the charge to anode) and discharge agent (discharge on anode electrode). The electro-catalytic activity of Fe 3+ /Fe 2+ ion was demonstrated by cyclic voltammetry and the rate for hydrogen evolution was measured at different current densities. At very low cell potential, smaller than 0.7 V, hydrogen begins to be produced, which is much less than the any noble metal catalysis water splitting hydrogen evolution. The electric energy consumption in our experiments for glucose-Fe ion system is 1.845 kW h Nm −3 H 2 at 100 mA cm −2 , which can save about 60.74% electric energy of traditional typical alkaline water electrolysis (4.7 kWh Nm −3 H 2 at U H2O = 2 V, the current density is 100 mA cm −2 ). Different from reported alcohol electrolysis, the biomass based electrolysis process does not require any noble-metal catalyst on the anode. [ABSTRACT FROM AUTHOR]