Preparation of 30%PMoV2@MOF@mSiO2 (MOF = MIL-101, HKUST-1, UiO-67, ZIF-8) catalysts and their oxidative desulfurization performance

PMoV₂ was encapsulated in four MOFs (MIL-101, HKUST-1, UiO-67, ZIF-8) with different cavity sizes and window sizes using a hydrothermal synthesis method. Then, a layer of mesoporous silica was coated on the surface of the MOFs to obtain four designed three-layer encapsulated catalysts 30%PMoV₂@MOF@mSiO₂. The physicochemical properties of the catalysts were characterized through various characterization methods, and the influence of different MOF window sizes of the four catalysts on the removal rate of four thiophene sulfides was investigated. The optimal reaction conditions were also explored for the optimal catalyst. The results indicate that under simulated fuel of 2400 ppm, 30%PMoV₂@UiO-67@mSiO₂ owns the highest catalytic activity. Under optimal conditions, the total removal rate of four thiophene compounds was 91.52 %, and after ten cycles, the efficiency could still reach 86.24 %. This is attributed to the sufficient cavity size of UiO-67, which provides assurance for the loading of PMoV₂ and the large window size, making it possible for the smooth reaction between sulfides and PMoV₂.