Controlling effect of TiO2 carrier on formed vanadium species for effective catalytic oxidization of chlorobenzene

ABSTRACT

Catalytic oxidization of the dioxins is critical to the atmosphere since medical-waste incineration is globally increased due to COVID-19. Vanadium supported TiO2 is the most-widely investigated catalyst. However, previous reports usually investigated V-Ti relationships after vanadate was loaded on TiO2 and an activation was completed. In comparison, this work emphasizes on the influence of TiO2 surface chemistries on properties of formed vanadium species during a thermal activation. The vanadate loaded TiO2 are detailedly analyzed by both experimental characterizations and theoretical calculations. As a result, TiO2 with more Ti4+ is inclined to be reductive, and promotes the formation of more low-valence vanadium and surface vacancies. On the contrary, TiO2 with more Ti3+ is inclined to be oxidative, and promotes the formation of more lattice oxygens and high-valence vanadium. When they were compared in catalytic oxidization of chlorobenzene, the Ti4+-induced catalyst attains a conversion of 98.0 % at 250 °C, far bigger than that (11.3 %) of the Ti3+-induced catalyst. The main result of this work helps readers to understand the process of the catalyst preparation, which is in favor of producing a more effective catalyst by regulating the catalyst carrier.