ELECTROCHEMICAL OXIDATION IN A CH4-H2O SYSTEM AT THE INTERFACE OF A PT ELECTRODE AND Y2O3-STABILIZED ZRO2 ELECTROLYTE .1. DETERMINATION OF THE PREDOMINANT REACTION PROCESS

In order to elucidate the electrochemical reaction in a CH4-H2O system at the interface of a porous Pt electrode/Y2O3- stabilized ZrO2 elect rolyte, measurements were made on the gas composition before and after the reaction under direct-current polarization and on electrochemical impedance spectra at 1073 K. The dominant electrochemical reaction wa s found to be the redox process of H-2/H2O where H-2 and CO were gener ated by the steam reforming in a CH4-H2O system. The polarization curv es showed good agreement with the model reported by Mizusaki et al. fo r a H-2-H2O system.