Hydrogen and electricity at once: An alkaline-acidic ethanol electroreformer

This study presents the results of an alkaline-acidic ethanol electroreformer producing hydrogen and electricity simultaneously. This is due to the pH gradient between an alkaline anolyte/fuel (1 mol/L ethanol and 4 mol/L KOH) and an acidic catholyte/comburent (1 mol/L H2SO4), separated by a K+-pretreated Nafion (R) 211 mem-brane to prevent chemical neutralization, resulting in an extra electromotive force. At 70 degrees C, the electroreformer delivers a maximum power density of 23 mW cm-2. An increase in the flow rate from 0.17 to 1.12 mL min-1 is also beneficial due to the mass transport enhancement. Finally, over the stability tests for 3 h at 50 degrees C and a flow rate of 1.12 mL min-1, it is possible to produce H2 at an average rate of 0.218 and 0.267 STP m3 m -2h- 1, and an average energy of 0.0877 and 0.0997 kWh m- 2 in recirculation and single-pass mode, respectively. The worse performance in the recirculation mode seems to be due to the accumulation of the ethanol electro-oxidation products, resulting in the poisoning of the catalyst surface.

Automated summary

This study presents a new alkaline-acidic ethanol electroreformer that can simultaneously produce hydrogen and electricity. The electroreformer utilizes a pH gradient between alkaline anolyte and acidic catholyte, separated by a Nafion(R) 211 membrane, to generate an extra electromotive force. The electroreformer achieves a maximum power density of 23 mW cm-2 at 70 degrees C.