干胶法制备钛硅沸石及其催化性能

以四丙基溴化铵为模板剂,以乙二胺(EDA)为碱源,采用干胶法制备了TS-1,并在此基础上引入介孔/大孔模板剂蔗糖而制备出多级孔道TS-1.采用X射线衍射、紫外-可见光谱及N2物理吸附-脱附等手段对所得样品进行了表征,并考察了它们催化噻吩(Th)及苯并噻吩(BT)氧化反应的性能.结果表明,随着釜底部n(EDA)/n(H2O)比的降低,TS-1结晶度、骨架Ti含量及其在Th氧化反应中的催化活性均升高.而当以乙胺和正丁胺为碱源时,TS-1难以晶化.所制备的多级孔道TS-1样品具有介孔/大孔孔道,在Th氧化反应中的催化活性高于TS-1;对于BT的氧化,当n(sucrose)/n(SiO2)为0.35时,制备的多级孔道TS-1样品的催化活性最高,BT脱除率可达100%,而TS-1则无催化活性.

Titanium Silicalite Synthesized by Dry Gel Conversion Method and Its Catalytic Performance

TS-1 zeolite was synthesized by dry gel conversion technique with ethylenediamine (EDA) as alkali source and tetrapropylammonium bromide as template. On this base, the hierarchical TS-1 was prepared with sucrose as meso/macropore template. The obtained samples were characterized by powder X-ray diffraction, UV-Vis spectroscopy, and N2 physical adsorption-desorption. The catalytic performance of the samples was evaluated using the oxidation of small molecular thiophene (Th) and bulky molecular benzothiophene (BT). With the decrease of the EDA/H2O molar ratio at the bottom of autoclave, TS-1 samples presented the trend of increase for the crystallinity, Ti content in framework, and the catalytic activity in Th oxidation. When the ethylamine and n-butylamine were used as the alkali source, it was difficult for TS-1 to crystallize. Hierarchical TS-1 possessed mesopore/macropore and exhibited higher catalytic performance than TS-1 in Th oxidation. For the oxidation of BT, hierarchical TS-1 synthesized with sucrose/SiO2 molar ratio of 0.35 presented the highest activity and the BT removal rate could reach almost 100%. However, the TS-1 had no catalytic activity in oxidation of BT.