Effects Of Template Agent And Preparation Process On The Structure And Catalytic Oxidation Desulfurization Performance Of Mesoporous HPMo/SiO₂ Catalyst

Reducing the sulfur content of fuel oil is an important measure of environmental protection,among which oxidation desulfurization has been widely studied by scientists at home and abroad because it has the advantages of mild reaction conditions,high desulfurization rate and effective removal of thiophene sulfur compounds which are difficult to be removed by hydrodesulfurization.In this paper mesoporous silica-supported phosphomolybdic acid catalysts were prepared by in-situ,synthesis using three different templates and different preparation process.The effects of different templates on the structure of catalyst and its catalytic oxidation and desulfurization performance were studied.The process of sulfide removal by catalytic oxidation with HPMo/SiO₂ catalyst prepared by template was discussed.The main conclusions are as follows:1.The structures of the catalysts were characterized by FTIR,XRD,SEM,and surface and pore structure analysis.The results showed that the catalysts which were prepared with TTAC,BTAC and DODMAC had amorphous structure,and phosphomolybdic acid was well dispersed on the carrier.Different templates improved the pore structure of the catalysts.The order of average pore diameter,specific surface area and pore volume of the catalysts made withthesethreetemplatesis:DODMAC-HPMo/SiO₂>BTAC-HPMo/SiO₂>TTAC-HPMo/SiO₂.2.After investigating the effects of phosphomolybdic acid loading and calcination temperature on the catalytic oxidation of DBT model oil over three catalysts,TTAC-HPMo/SiO₂,BTAC-HPMo/SiO₂ and DODMAC-HPMo/SiO₂,the three kinds of catalysts which prepared under the optimum preparation conditions showed high selectivity and catalytic activity in the catalytic oxidation desulfurization of DBT and BT model oil.The kinetic laws of the catalytic oxidation desulfurization of DBT and BT were consistent with the apparent first-order kinetic laws.All three catalysts can completely remove DBT,and the orderoftheremovalactivityofBTis:DODMAC-HPMo/SiO₂>BTAC-HPMo/SiO₂>TTAC-HPMo/SiO₂.In the same reaction system,the order of oxidation removal of DBT and BT from model oil is BT>DBT.3.After repeatedly using the three catalysts for 5 times,the oxidation removal rate of sulfur-containing target compounds of DBT is 91.5%,91.8%,92.5%,the oxidation removal rate of sulfur-containing target compounds of BT is 90.5%,86.5%,87.3%,showing good reusability.