Hydrogen production via CH4 and CO assisted steam electrolysis

Porous composite anodes consisting of a yttria-stabilized zirconia (YSZ) backbone that was impregnated with CeO2 and various amounts of metallic components including Cu, Co and Pd were fabricated. The performance of these anodes was then tested in a solid oxide water electrolysis cell under conditions where the anode was exposed to the reducing gasses H-2, CH4 and CO. The reducing gasses were used to decrease the electrochemical potential of the cell and increase overall efficiency. The results of this study show that Cu-CeO2-YSZ anodes have low catalytic activity for the oxidation of CO and CH4 and are not very effective in lowering the cell potential while operating in the reducing gas assisted mode. The addition of Co to the Cu-CeO2-YSZ anode resulted in a modest increase in the catalytic activity and enhanced the thermal stability of the anode. A Pd-C-CeO2-YSZ anode was found to have the highest catalytic activity of those tested and gave the largest reductions in the operating potential of the solid oxide electrolysis cell.