DESs/SG催化剂的制备及其氧化脱硫性能

通过溶胶-凝胶法将脯氨酸基低共熔溶剂负载到硅胶上制得DESs/SG型催化剂。采用FT-IR、XRD、SEM/EDS及N_2吸附-脱附等手段对催化剂的结构进行表征。结果发现,低共熔溶剂可以成功负载到硅胶中,硅胶的比表面积和孔体积有所下降,而孔径增大。以DESs/SG为吸附剂和催化剂,H_2O_2为氧化剂,研究其对模拟油中的二苯并噻吩的脱除性能,考察了低共熔溶剂负载量、反应温度、n(H_2O_2)/n(S)比、催化剂用量、含硫化合物的类型以及催化剂循环使用次数对脱硫效率的影响。结果表明,在最优脱硫条件下,DESs/SG对二苯并噻吩、4,6-二甲基二苯并噻吩和苯并噻吩的脱硫率分别为97%、96. 5%和46. 4%;催化剂循环使用九次后,催化脱硫效率仍高达89. 4%。

Preparation of DESs/SG catalyst and its performance in the oxidative desulfurization

DESs/SG catalyst was prepared by supporting the proline-based deep eutectic solvent (DES) on the silica-gel (SG) matrix using a sol-gel method; the catalyst structure was characterized by FT-IR, XRD, SEM/EDS and N₂ adsorption-desorption. The results showed that the DESs were successfully incorporated into the silica-gel matrix, leading to a decrease in the surface area and pore volume, but an increase in the pore diameter. With hydrogen peroxide as oxidant, the catalytic performance of DESs/SG in the oxidative desulfurization of a model oil containing dibenzothiophene (DBT) was investigated; the effects of deep eutectic solvent loading, reaction temperature, n(H₂O₂)/n(S) ratio, catalyst amount, sulfur compound type and catalyst recycle times on the desulfurization efficiency were considered. The results indicated that under optimum desulfurization conditions, the desulfurization degrees for DBT, 4,6-dimethyl-dibenzothiophene (4,6-DMDBT) and benzothiophene (BT) over the DESs/SG catalyst were 97%, 96.5% and 46.4%, respectively; after recycling for 9 times, the DESs/SG catalyst still displayed a desulfurization degree of above 89.4%.