【摘要】 以十二胺为模板剂,正硅酸乙酯为硅源,钛酸四丁酯为钛源,直链烷烃正己烷或正辛烷为有机添加剂,在室温下合成出具有较大孔径的Ti-HMS分子筛.研究了烷烃对Ti-HMS分子筛的扩孔作用及对分子筛结晶度和催化性能的影响.结果表明,加入的烷烃越多,分子筛的孔径越大;烷烃链长越长,对Ti-HMS的扩孔作用越显著.与不加烷烃的Ti-HMS相比,加入烷烃后,分子筛的结晶度及四配位骨架钛的含量均有所降低,而且加入的烷烃量越多,影响越明显.将加入烷烃所得的Ti-HMS用于模拟燃料中4,6-二甲基二苯并噻吩的氧化脱除反应,结果发现,Ti-HMS的催化氧化活性有所提高,对4,6-二甲基二苯并噻吩的脱除速率增大.更多还原

【Abstract】 Ti-HMS was synthesized at ambient temperature using dodecylamine as the template,tetraethylorthosilicate as the silicon source,tetrabutylorthotitanate as the titanium source,and incorporating straight chain alkanes as swelling agents.Effects of the dosage and the number of carbon atoms of the alkanes on the structural and catalytic properties of the Ti-HMS were investigated.The molecular sieve was characterized by X-ray diffraction(XRD),N2 physical adsorption,diffuse reflectance ultraviolet-visible(UV-Vis) spectroscopy,and transmission electron microscopy(TEM).The catalytic performance of Ti-HMS was evaluated by the oxidative removal of 4,6-dimethyl dibenzothiophene(4,6-DMDBT).The Ti-HMS samples obtained possess wormlike mesostructure,which was confirmed by XRD and TEM analysis.The Ti-HMS prepared with the addition of alkanes has lower crystallinity and framework titanium content than the original sample.The physical adsorption results exhibit that the pore diameter of Ti-HMS,as well as the surface area and pore volume,was enlarged with the addition of alkanes.In addition,the pore diameter of Ti-HMS increased with the increase in the dosage of alkanes and the number of carbon atoms in alkane molecules.The samples thus obtained have preferable activity than the original Ti-HMS for the oxidative removal of 4,6-DMDBT,which can be attributed to the improvement of their diffusion performance arising from the larger pore diameter.更多还原