VO2 uniformly supported by 3D g-C3N4: A highly effective catalyst for deep oxidative desulfurization

Abstract

A supported catalyst VO2/3D g-C3N4 was prepared by calcination and hydrothermal reduction method. Characterizations proved that the synthesized carrier g-C3N4 is a three-dimensional material with a porous structure. The loading process was to the benefit of the uniform dispersion of the VO2, while the shortcoming of easy agglomeration was overcome and the catalytic activity was improved. Through characterization and activity testing, the composition, morphology and desulfurization performance of VO2/3D g-C3N4 were analyzed. Experimental results showed that 10% VO2/3D g-C3N4 could activate molecular oxygen under milder conditions, which could further oxidize sulfur compounds in the model oil into easily removable sulfones, and deep desulfurization was achieved. The free radical elimination experiments, ESR, and GC–MS analyses were taken to find out the possible desulfurization mechanism. Molecular oxygen was activated into superoxide radical, which efficiently oxidized dibenzothiophene (DBT) to the DBT sulfone (DBTO2). Furthermore, 10% VO2/3D g-C3N4 still had high desulfurization efficiencies after 10 cycles.