Electrochemical promotion of Ag catalyst for the low temperature combustion of toluene
Résumé
This paper is the first report on the possibility to electrochemically promote the catalytic complete oxidation of toluene on Ag films deposited on Y2O3 stabilized ZrO2 (YSZ) at relatively low temperature (300°C). It was found that the toluene conversion into CO2 and H2O on an Ag catalyst can be significantly promoted upon cathodic polarization, i.e. oxygen removal from the catalyst surface. Such an enhancement is strongly non-Faradaic. Conversely, anodic polarization, i.e. O2- supplying from the YSZ support toward the catalyst, has no significant influence on the activity of Ag film. The promotion effect is therefore typically an electrophilic one. Further investigation indicates that there are some optimum values for the negative potential or current. Beyond these values, the activity of catalyst remains the same, but the Faradaic efficiency decreases.