Effects of support for cobalt catalysts in catalytic oxidation of toluene

Co-based catalysts have attracted increasing attention for its excellent catalytic activity in catalytic oxidation reactions. Determining the support effect of Co catalysts is essential for the efficient catalytic performance of toluene in industrial applications. In this study, Co catalysts supported on the selected Nb2O5 exhibited the best catalytic activity and stability. The characterization and DFT calculation results revealed that due to the unique physicochemical properties of monoclinic Nb2O5 supports, there was a strong interaction between the carrier Nb2O5 and the active component Co3O4. The DFT calculation also confirmed that the easier and stronger adsorption of toluene on Co3O4/Nb2O5 (-1.34 eV), furthermore, the oxygen vacancy formation energy (Ev) and oxygen adsorption energy evidenced the enhancement of surface oxygen migration, oxygen adsorption and dissociation capacity of Co3O4/Nb2O5 catalyst. Therefore, the 10%Co/Nb2O5 catalyst possessed abundant surface oxygen vacancies and electron-rich Co3O4 structure, which boosted the toluene and oxygen molecules adsorption and activation capacity. This study reveals the support effect of Co supported catalyst, which has guiding significance for industrial application.