Catalytic and Electrocatalytic Oxidation of Methane on Palladium Electrodes in a Solid Electrolyte Cell

The catalytic oxidation of methane on polycrystalline palladium films was studied at 550-750 degrees C and atmosheric total pressure. The reaction was studied under both open and closed-circuit. Under open circuit, and when yttria-stabilized zirconia (YSZ) was used as solid electrolyte, the technique of Solid Electrolyte Potentiometry (SEP) was used to monitor the thermodynamic activity of oxygen adsorbed on the Pd electrode during reaction. The main products were those of complete oxidation, i.e. CO(2) and H(2)O. Under closed-circuit, the effect of electrochemical oxygen "pumping" to or from the catalyst was studied. Non-faradaic (NEMCA) phenomena were observed but the reaction rate enhancement factors (A) were not as large as with previously studied catalytic systems.