以阳离子聚合物为介孔模板合成多级孔TS-1

Synthesis of Hierarchical TS-1 Zeolite Using Cationic Polymer as Mesoporous Template

分别以阳离子聚季铵盐-7和聚季铵盐-6为介孔模板,通过水热法合成了多级孔TS-1沸石,采用X射线衍射、紫外可见光谱、扫描电镜、透射电镜及N2吸附-脱附等手段对所得样品进行了表征,并考察了其催化苯并噻吩及噻吩氧化反应性能.结果表明,聚季铵盐-7的加入对多级孔TS-1的晶化、钛物种的配位状态及晶粒形貌的影响不大;而随着聚季铵盐-6用量的增加,多级孔TS-1的晶貌逐渐由立方状转变为长方状晶粒.两种聚合物合成的多级孔TS-1都具有明显的介孔孔道,而且具有明显高于TS-1的催化苯并噻吩氧化反应和相似的噻吩氧化反应性能.

Hierarchical TS-1 zeolites were synthesized successfully by the hydrothermal method using cationic polyquaternium-7 and polyquaternium-6 as mesoporous template,respectively.The obtained samples were characterized by X-ray diffraction,UV-Visible spectroscopy,scanning electron microscopy,transmission electron microscopy,and N2 adsorption-desorption.The catalytic performance of the materials was evaluated for the oxidation of bulky molecular benzothiophene and small molecular thiophene.The results show that the addition of polyquaternium-7 has a little effect on the crystallization,the state of titanium sites,and the crystal morphology of hierarchical TS-1.However,the crystal morphology of hierarchical TS-1 changes from small cubic crystals to large rectangular crystals with increasing content of polyquaternium-6.Hierarchical TS-1 zeolites synthesized from the two kinds of polymers possess obvious mesoporous channels.Moreover,they give much higher activity in benzothiophene oxidation than TS-1,which is attributed to the presence of additional mesopores for reducing the diffusion limitation.In addition,hierarchical TS-1 zeolites also exhibit the similar oxidative activity for thiophene to TS-1 and give the removal rate of 100% for 2 h.