Electrochemical promotion of ethylene and propylene oxidation on Pt deposited on yttria-titania-zirconia

The effect of electrochemical promotion (NEMCA) was investigated for the ox idation of ethylene and propylene on Pt deposited on 4.5 mol% Y2O3-10 mol% TiO2-85.5 mol% ZrO2 (YZTi10) which is believed to be an ionic conductor wit h some n-type electronic conductivity in reducing environments. It was foun d that YZTi10 can induce the effect of electrochemical promotion for both C 2H4 and C3H6 oxidation with apparent Faradaic efficiency, Lambda, values up to 10(3). The rate enhancement ratio, rho = r/r(o), however was found to b e much smaller than in the cases where 8 mol% Y2O3-stabilized-ZrO2 (YSZ) or even TiO2 is used as the solid electrolyte and O2- donor. The origin of th is difference is not clear. (C) 2000 Elsevier Science B.V. All rights reser ved.