REACTION KINETICS OF CH_4-H_2O GAS-MIXTURES ON Pt/YSZ SYSTEM

摘要

As a fundamental research on the internal reforming type SOFC anode reaction, a study was made on the reaction kinetics of the CH_4-H_2O gasmixtures at the interface of a porous Pt electrode / Y_2O_3-stabilized ZrO_2 (YSZ) electrolyte at 873-1173 K. The rate of electrochemical oxidation of CH_4 and that of the reforming products, H_2, CO, and C, were determined as a function of the electrode potential and temperature. It was found that the dominant electrochemical reaction is the oxidation of H_2. The rate of the electrochemical oxidation of CO in a CH_4-H_2O system was found larger than that in a CO-CO_2-inert gas system at temperatures below 1073 K. It was suggested that the electrochemical CO oxidation rate is enhanced by the co-existing H_2-H_2O.