Characterisation and activity of mixed metal oxide catalysts for the gas-phase selective oxidation of toluene

Mixed metal bi-component oxide catalysts, including Fe/Mo, U/Mo, U/W, Fe/U, U/V and U/Sb have been prepared, characterised evaluated for gas phase selective toluene oxidation. Selective oxidation activity to form benzaldehyde was exhibited by U/Mo U/W mixed catalysts. The Fe/Mo catalyst produced the highest yield. Catalysts that formed also a range of by-products, these were other partial coupling products, preliminary studies suggests they from secondary reactions benzaldehyde. Sb/U catalysts only total carbon oxides. X-ray diffraction, laser Raman spectroscopy temperature programmed reduction. Single molybdate phases identified mixture uranium WO3 catalyst. Results suggest formation is important toluene. In contrast, U/Fe U3O8 V2O5, whilst Fe/U comprised highly dispersed iron on UO3. presence responsible did not exhibit oxidation, but previous demonstrated exhibits high propene Similar behaviour has observed in this study, it apparent propene/propane vice versa.