Ag/ZrO 2 and Ag/Fe–ZrO 2 catalysts for the low temperature total oxidation of toluene in the presence of water vapor

New mesoporous and well-structured Ag-based catalysts (xAg/ZrO2 and xAg/Fe–ZrO2 with x = 2 wt%) have been investigated in the total oxidation of toluene with water vapor. The results showed that the catalytic activity of systems increases, in the 350–550 °C temperature range, following this order: ZrO2 < Fe–ZrO2 < Ag/ZrO2 ≈ Ag/Fe–ZrO2. Nevertheless, it was revealed that Ag/Fe–ZrO2 is the most active solid for the low temperature total oxidation of toluene (< 350 °C). The highest low temperature activity of this new catalyst can be related to the presence of more reactive surface oxygen, new active redox and acidic sites at Ag/Fe–ZrO2 surface, most probably generated by the simultaneous presence of Ag and Fe species.