Understanding the crucial roles of catalyst properties in ethyl acetate and toluene oxidation over Pt catalysts

Platinum catalysts supported on metal oxidesupports (CeO2–ZrO2, CeO2, ZrO2 and Al2O3) were prepared by a facile impregnation method. Significant differences in properties (medium strong acid density, Pt0 species content, Pt dispersion and oxygen density, etc.) were observed among these catalysts. The highest density of medium-strong acid sites, Pt dispersion, and content of metallic Pt0 species were observed in Pt/Al2O3 catalyst, and Pt/CeO2–ZrO2 catalyst gave the highest density of oxygen vacancy. Moreover, the activity orders of these Pt catalysts for ethyl acetate oxidation were very different from that of toluene. The T99 of ethyl acetate oxidation over the Pt/CeO2–ZrO2, Pt/CeO2, Pt/ZrO2 and Pt/Al2O3 catalysts are at 190, 210, 230 and 250 °C, respectively. Ethyl acetate oxidation activity is in the order: Pt/CeO2–ZrO2 > Pt/CeO2 > Pt/ZrO2 > Pt/Al2O3. The T99 of toluene oxidation over the Pt/CeO2–ZrO2, Pt/CeO2, Pt/ZrO2 and Pt/Al2O3 catalysts are 220, 260, 190 and 250 °C, respectively. Toluene oxidation activity is in order: Pt/ZrO2> Pt/CeO2–ZrO2 > Pt/Al2O3 > Pt/CeO2. The catalytic activities of these Pt catalysts for ethyl acetate mainly depend on the oxygen vacancy density, while the synergistic catalysis of Pt0 species and oxygen vacancies play an important role in toluene oxidation. This work could deepen our understanding to differentiate the dominant roles of catalyst properties on ethyl acetate and toluene oxidation over Pt catalysts.