Complete oxidation of toluene on Co₃O₄/CeO₂–ZrO₂–SnO₂ catalysts

Novel Co3O4/CeO2–ZrO2–SnO2 catalysts were prepared by evaporative drying and subsequent calcination of the complexes, and catalytic combustion of toluene on the catalysts was investigated. Tin oxide (SnO2) and cobalt oxide (Co3O4) served as promoters to facilitate the toluene oxidation. Introduction of SnO2 into the CeO2–ZrO2 lattice was effective at enhancing the oxygen release and storage properties, leading to an increase in the toluene oxidation activity. This improvement of the oxygen release ability of the catalyst can be ascribed to the simultaneous reduction of Ce4+ and Sn4+ in the CeO2–ZrO2–SnO2 solid solutions. Co3O4 on the CeO2–ZrO2–SnO2 supports promoted toluene oxidation in lieu of platinum, which is usually employed but leads to high production costs. By the optimization of the catalyst composition, complete oxidation of toluene was realized at 260 °C on Co3O4(16.9 wt%)/Ce0.67Zr0.18Sn0.15O2.0.