Optimization of dendritic TS-1/Silica micro–mesoporous composites for efficient hydrodesulfurization of dibenzothiophene and 4,6-dimethyldibenzothiophene

A novel composite material(TD)composed of TS-1 microcrystalline and dendritic mesoporous silica nanospheres(DMSNs)was successfully prepared.The TD composite material had open pore structure and large specific surface area,which was conducive to the mass transfer of reactants and products.The Ti element in TS-1 could be used as an electron assistant,and the spillover d-electrons were conducive to the improvement of the sulfidation and dispersion of MoS_(2),thereby forming more type II MoS_(2) active phases.The incorporation of Ti could bring more Brønsted(B)and Lewis(L)acid,which was conducive to the hydrogenation pathway(HYD)selectivity(41.2%)of dibenzothiophene(DBT)hydrodesulfurization(HDS)and isomerization(ISO)route selectivity(21.9%)of 4,6-dimethyldibenzothiophene(4,6-DMDBT)HDS,thus improve the HDS activity of DBT and 4,6-DMDBT.NiMo/TD-70(Aging temperature=70℃)had the best HDS activities of DBT(99.0%)and 4,6-DMDBT(93.7%)due to its large open pore structure,good acidity,suitable metal-support interaction(MSI)and perfect dispersion of the metallic active sites.

The effect of chelating agent on hydrodesulfurization reaction of ordered mesoporous alumina supported Ni Mo catalysts

In this paper,ordered mesoporous alumina(OMA)support with the high surface area(328 m^(2)g^(-1))and the large pore volume 0.74(cm^(3)·g^(-1))was synthesized by homogeneous precipitation method.And the influence of EDTA on the physical and chemical properties of the modified catalysts was also studied.The characteristic results showed that the addition of EDTA could adjust the metal-support interaction and improved the acidity of the corresponding catalyst.Combined with the catalytic performance results,the EDTA-modified Ni Mo E(1.0)/OMA catalyst displays the highest DBT hydrodesulfurization conversion(97.7%).

Hierarchically porous Beta/SBA-16 with different silica-alumina ratios and the hydrodesulfurization performances of DBT and 4,6-DMDBT

Hierarchically porous Beta/SBA-16(BS)composite materials,combining the characteristics of the acidity from the Beta zeolite and the three-dimensional structure from SBA-16,were synthesized successfully through a two-step in-situ assembly hydrothermal crystallization method.A series of Ni Mo catalysts supported on BS with different silica-alumina ratios were prepared.The supports and the corresponding catalysts were characterized by XRD,N_(2) physisorption,^(27)Al MAS NMR,TEM,pyridine-FTIR,Raman,XPS and HRTEM.The activities of series catalysts were evaluated by the hydrodesulfurization(HDS)performances of dibenzothiophene(DBT)and 4,6-dimethyldibenzothiophene(4,6-DMDBT).It was found that the Beta crystallites were embedded into SBA-16 through silanols accompanied by dealumination on the T3-T9 sites of Beta crystallites.Ni Mo/BS-3 with a silica-alumina ratio of 100 exhibited the highest DBT and 4,6-DMDBT HDS activities at the WHSV value of 10 h^(-1),with the conversions of 95.9%and 86.9%respectively,due to the synergistic effects of the suitable specific surface areas,the relatively large pore size,appropriate acidity,the relatively high sulfidation degree,moderate dispersity and good stacking degree of Mo S;active phases.