Self-Assembly Preparation of Al₂O₃/MoS₂ Bifunctional Catalyst for Highly Efficient Reduction of SO₂ to Elemental Sulfur

MoS2 has been widely applied in SO2 desulfurization and hydrodesulfurization due to its special two-dimensional sheet structure and high-performance of reduction properties. MoS2 nanospheres assembled by the sheet structure of MoS2 were synthesized through a facile hydrothermal synthesis method with the assistance of a surfactant [polyvinylpyrrolidone (PVP)]. The structure of MoS2 was related to the amount of PVP addition during preparation, where the nanosheets were formed into nanospheres, and the nanospheres were generated into hollow spheres further increasing the amount of PVP addition. Meanwhile, the nanosphere size tended to decline, which was beneficial to the improvement of SO2 conversion. Research indicated that porous Al2O3 grown on the nanospheres exposed a larger amount of Lewis acid on the surfaces than that grown on the nanoflower-like structures. The SO2 conversion and sulfur selectivity were 97.05% and 98.21% under the optimized conditions. The modulation of the MoS2 morphology has been proved to be an available method to enhance the reduction of SO2 to elemental sulfur.