ACTIVATION OF CATALYST FOR GAS-PHASE COMBUSTION BY ELECTROCHEMICAL PRETREATMENT

The catalytic activity of an IrO2 catalyst used as an electrode on a Y SZ solid electrolyte cell for the gas-phase combustion of ethylene can be increased by electrochemical pretreatment. Thus, the polarization of the IrO2 electrode during 90 min at 300 mu A, relative to a gold el ectrode, both deposited on YSZ, increases the activity of the IrO2 cat alyst after current interruption by a factor of 3. In situ catalyst wo rk function measurements showed that after the electrochemical pretrea tment the IrO2 catalyst obtains higher work function. The activation o f the catalyst is explained through the formation of a higher oxide, I rO2+delta.