Ti-HMS和TS-1分子筛结构和催化性能的对比研究  

Comparative Study of Structure and Catalytic Properties of Ti-HMS and TS-1 Molecular Sieves

作　　者：金长子[1] 李钢[1] 王祥生[1] 王云[1] 刘海鸥[1] 

机构地区：[1]大连理工大学精细化工国家重点实验室催化化学与工程系,辽宁大连116012

出　　处：《催化学报》2007年第2期170-174,共5页

基　　金：高等学校全国优秀博士学位论文作者专项资金(200346);新世纪优秀人才支持计划(NCET-04-0270);国家自然科学基金(20406005);中国石油天然气集团公司石油科技中青年创新基金(04E709).

摘　　要：采用长链十二烷基胺为模板剂,成功合成出含钛中孔分子筛Ti-HMS,并针对其晶化过程、结构特征以及催化性能与修正经典法制备的微孔分子筛TS-1进行了对比.结果表明,中孔分子筛Ti-HMS的晶化机理不同于微孔分子筛TS-1的晶化机理.随着晶化温度的提高,Ti-HMS分子筛的相对结晶度降低,且晶化过程中母液的pH值变化不大.TEM照片显示,Ti-HMS分子筛的孔壁整体上呈无定形,在局部区域可能存在晶态或者类晶态物种.与TS-1分子筛相比,Ti-HMS分子筛的活性中心(骨架钛)处在畸变的四面体环境中.中孔分子筛Ti-HMS可以满足大分子硫化物(如苯并噻吩)氧化反应的要求;对于小分子硫化物(如噻吩)的氧化反应,微孔分子筛TS-1催化剂效果更好.The mesoporous molecular sieve Ti-HMS was synthesized using long-chain dodecylamine as the template. The crystallization process, structural properties, and catalytic performance of Ti-HMS were compared with that of microporous molecular sieve TS-1 prepared by modified classical synthesis. With the increase in crystallization temperature, the relative crystallinity of Ti-HMS decreased, and the pH value of the mother liquid changed little during the crystallization process, which might be attributed to its crystallization mechanism differed from TS-1. Unlike TS-1 having typical crystalline character, the Ti-HMS molecular sieve exhibited amorphous characteristics except for the lattice fringe in some area of its HRTEM image. The UV-Vis spectrum indicated that the framework Ti species of Ti-HMS were in distorted tetrahedral environment. In oxidation of bulky sulfur compounds such as benzothiophene, the Ti-HMS molecular sieve had very high catalytic activity, with a benzothiophene removal rate of about 100 %. However, TS-1 was inactive for this reaction because of the diffusion restriction. In addition, Ti-HMS showed lower activity than TS-1 for selective oxidation of small molecular reactants owing to its weaker oxidative ability and lower shape selective catalytic performance.

关 键 词：中孔分子筛 微孔分子筛 晶化 噻吩 苯并噻吩 氧化 

分 类 号：O643.36[理学—物理化学]