Preparation of vanadium-MFI zeolite for oxidative desulfurization with the aid of ammonium carbonate

Vanadium-MFI zeolites with enhanced vanadium insertion were synthesized through an ammonium carbonate-assisted hydrothermal synthesis and applied as heterogeneous catalyst for the oxidation of organosulfur compounds DBT and 4,6-DMDBT. The prepared vanadium-MFI zeolites were characterized by Scanning electron microscope, Transmission electron microscope, X-ray diffraction, Fourier-transform infrared spectroscopy, UV–vis diffuse reflectance spectroscopy and Raman spectroscopy. The obtained UV–vis spectra disclosed that addition of ammonium carbonate could effectively strengthen the insertion of vanadium element, and on the same time enhance the tetrahedral framework vanadium percentage in vanadium species. The synthesized N-VS(4) zeolite could realize almost complete oxidation of DBT in 240 min, which is obviously better than N-VS(3) and N-VS(5) zeolite. Moreover, the calcined recycled N-VS(4) zeolite shows good re-usability for more than four cycles, which indicates it is an active and stable heterogeneous catalyst.