超顺磁催化剂H_3PW_(12)O_(40)/Fe_3O_4@SiO_2的制备、结构表征及在汽油烷基化脱硫中的应用

Preparation and structure characterization of superparamagnetic supported catalyst H_3PW_(12)O_(40)/Fe_3O_4@SiO_2 and its application in olefinic alkylation desulfurization

采用改进St?ber法制备超顺磁Fe3O4@SiO2复合粒子作为催化剂载体,再通过浸渍法将H3PW12O40(HPW)负载在Fe3O4@SiO2载体上,制备了一系列超顺磁负载型催化剂HPW/Fe3O4@SiO2。并使用X射线衍射(XRD)、傅里叶红外(FT-IR)、氨的程序升温脱附(NH3-TPD)、扫描电镜(SEM)、N2吸附-脱附和振动样品强磁计(VSM)对催化剂进行表征。结果表明,HPW固定并均匀分散在Fe3O4@SiO2载体上,40%HPW/Fe3O4@SiO2催化剂具有较高的饱和磁强度(30.1 emu·g?1)和较大的比表面积(303.6 m2·g?1),并可用外加磁场进行分离。采用40%HPW/Fe3O4@SiO2催化噻吩与1-辛烯组成的模拟汽油的烷基化脱硫反应,在160℃下反应2 h,噻吩转化率达到85.5%,有较好的催化脱硫性能,且可以多次循环利用。

Fe3O4@SiO2 nanocomposite was prepared via modified Stober method and used as catalyst support. Superparamagnetic supported catalystsprepared by loading H3PW12O40 （HPW） onto Fe3O2@SiO2 support through a wet impregnation method, were used for alkylation reaction, and characterized by X-ray diffraction （XRD）, Fourier transform infrared （FT-IR）, NH3-temperature programmed desorption （TPD）, scanning electron microscope （SEM）, N2-adsorption and vibrating sample magnetometer （VSM）. Their physicochemical characterization revealed that HPW had been immobilized and dispersed on Fe304@SiOz. Moreover, 40%（mass） HPW loading catalyst, been of high magnetization 30.1 emu. g^-1, mesoporous structure and the surface area 303.6 m2 o g-l, could be considered to be a proper catalyst for olefinic alkylation of thiophenic sulfur （OATS） and they can be easy separated by external magnetic field. In addition, their catalytic activity was also investigated in alkylation reaction of a model mixture of thiophene and 1-octene, and the conversion of thiophene was up to 85.5% after 2 h at 160℃.