Role of rhodium anode in the YSZ-aided CH4 oxidation into syngas

Direct partial oxidation of CH4 into synthesis gas has been studied by usin g an Rh/YSZ/Ag electrochemical reactor. Oxygen was pumped from the Ag catho de to the Rh anode through the YSZ to produce adsorbed oxygen species on th e surface of the Rh anode. The adsorbed oxygen species can oxidize CH4 to C O/H-2 directly, i.e. not via combustion of CH4 to CO2 and H2O followed by t he reforming reactions of CH4 with CO2 and H2O. The oxygen pumping treatmen t through the YSZ affected significantly the surface morphology of the Rh a node. A three-dimensional network consisting of fine Rh particles was forme d by the oxygen pumping treatment, resulting in an enhanced migration of ox ygen species from the triple-phase boundary to the Rh anode surface of high surface area. Thus, an enormous increase in the production of CO/H-2 by th e direct partial oxidation of CII, was observed over the Rh anode treated b y the oxygen pumping. (C) 2000 Elsevier Science B.V. All rights reserved.