Electrochemical promotion of RuO2 catalysts for the combustion of toluene and ethylene

The electrochemical promotion of the complete catalytic oxidation of ethylene and toluene on RuO₂Catalyst films deposited on Y₂O₃-stabilized-ZrO₂ (YSZ) has been investigated at temperatures 400 to 500°C. Anodic polarization (1.5 V), i.e. O^2– supply from the YSZ support to the catalyst, is found to enhance the rates of ethylene and toluene oxidation by a factor of 10 and 8 respectively. Cathodic polarization (–1.5 V) i.e. oxygen removal from the catalyst, enhances the oxidation rates by a factor of 3 and 4, respectively. These rate enhancements are strongly nonFaradaic. The kinetics, positive order in both reactants, and the promotional results, inverted-volcano type for both reactions, conform to the recently found rules of electrochemical promotion.*To whom correspondence should be addressed. E-mail: cat@chemeng.upatras.gr