ELECTROCHEMICAL PROMOTION OF IRO2 CATALYST ACTIVITY FOR THE GAS-PHASECOMBUSTION OF ETHYLENE

The catalytic activity for the gas phase combustion of ethylene of an IrO2 film, used as electrode in a solid electrolyte cell, can be incre ased by polarizing the metal-solid electrolyte interface. The catalyti c activity remains higher even after current interruption. To explain the increase in the open circuit rate after polarization we speculate that the IrO2 catalyst is oxidized at the catalyst-solid electrolyte i nterface, forming IrO2+delta, which is transported by surface and/or b ulk diffusion to the gas exposed catalyst, thus modifying its catalyti c activity.