Formation of hydrogen from the CO-H2O system using porous Gd-doped ceria electrochemical cell with MnO cathode and Fe3O4 anode

This paper reports the outlet gas composition and phase change of electrodes during the CO-H2O reaction (CO + H2O -> H-2 + CO2) using an electrochemical cell with MnO-GDC (Gd-doped ceria: Ce0.8Gd0.2O1.9) cathode/porous GDC electrolyte/Fe3O4-GDC anode system. In the cathode, oxidation of MnO by H2O (3MnO + H2O Mn3O4 + H-2) and electrochemical reduction of Mn3O4 occurred (Mn3O4 + 2e-3MnO + O2-). In the anode, reduction of Fe3O4 by CO (Fe3O4 + CO 3FeO + CO2) and electrochemical oxidation of FeO occurred (3FeO + O-2-Fe3O4 + 2e(-)). H-2 and CO2 gases were produced through the above catalytic reactions. The fraction of H-2 gas in the outlet gas increased at a high heating temperature and was 30-50% at 700 degrees C. As a parallel reaction of the CO-H2O reaction, the supplied CO gas was decomposed to CO2 and solid carbon over Fe3O4 in the anode at low temperatures (disproportion of CO, 2CO -> CO2 + C). (C) 2014 The Ceramic Society of Japan and the Korean Ceramic Society. Production and hosting by Elsevier B.V. All rights reserved.