The catalytic activity of IrO2 catalyst films for the gas phase combustion of ethylene can be increased by up to a factor of 10 via anodic polarization of the IrO2 catalyst relative to a Au electrode both deposited on Y2O3-stabilized ZrO2 solid electrolyte. The steady-state increase in the catalytic reaction rate is typically 200 higher than the expected rate increase of ethylene combustion calcd. from Faraday's law. This is the 1st demonstration of the effect of nonfaradaic electrochem. modification of catalytic activity (NEMCA) using a metal oxide catalyst. [on SciFinder (R)]