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

Platinum catalysts supported on metal oxidesupports (CeO 2 -ZrO 2 , CeO 2 , ZrO 2 and Al 2 O 3 ) were prepared by a facile impregnation method. Significant differences in properties (medium strong acid density, Pt 0 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 Pt 0 species were observed in Pt/Al 2 O 3 catalyst, and Pt/CeO 2 -ZrO 2 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 T 99 of ethyl acetate oxidation over the Pt/CeO 2 -ZrO 2 , Pt/CeO 2 , Pt/ZrO 2 and Pt/Al 2 O 3 catalysts are at 190, 210, 230 and 250 °C, respectively. Ethyl acetate oxidation activity is in the order: Pt/CeO 2 -ZrO 2 > Pt/CeO 2 > Pt/ZrO 2 > Pt/Al 2 O 3 . The T 99 of toluene oxidation over the Pt/CeO 2 -ZrO 2 , Pt/CeO 2 , Pt/ZrO 2 and Pt/Al 2 O 3 catalysts are 220, 2 60, 190 and 250 °C, respectively. Toluene oxidation activity is in order: Pt/ZrO 2 > Pt/CeO 2 -ZrO 2 > Pt/Al 2 O 3 > Pt/CeO 2 . The catalytic activities of these Pt catalysts for ethyl acetate mainly depend on the oxygen vacancy density, while the synergistic catalysis of Pt 0 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. The catalytic activities of these Pt catalysts for ethyl acetate mainly depend on the oxygen vacancy density, whereas the synergistic catalysis of Pt 0 species and oxygen vacancies play important roles in toluene oxidation.