Ti接枝MCM-48对苯羟化反应的化学亲和选择性及化学稳定性研究  

Study of the Catalytic Performance and Stability of Ti-grafted MCM-48 in the Hydroxylation Reaction of Benzene

作　　者：郭宗英[1] 何静[1] 邓玲玲[1] 段雪[1] 

机构地区：[1]北京化工大学可控化学反应科学与技术基础教育部重点实验室,北京100029

出　　处：《精细化工》2002年第7期406-408,433,共4页Fine Chemicals

基　　金：国家重点基础研究发展规划 ( 973)项目 (G2 0 0 0 0 480 0 9);国家自然科学基金项目 ( 2 0 1730 0 3)

摘　　要：合成了具有较好长程结构和孔结构的Si MCM - 48,以合成后表面接枝改性的方法制备了表面Ti含量不同的Ti接枝MCM - 48催化剂 ,通过X射线衍射 (XRD)、低温N2 吸 -脱附、X射线光电子能谱 (XPS)及原子吸收光谱等对催化剂作了表征 ,Ti接枝MCM - 48仍具有良好的长程有序结构和孔结构 ,其比表面积高于 95 0m2 ·g-1,孔径分布窄 ,随Ti接枝量提高 ,最可几孔径由 2 5nm逐渐降低至 1 9nm。将Ti接枝MCM - 48催化剂用于苯羟化反应 ,研究了其苯羟化性能和结构稳定性 ,结果发现 :Ti接枝MCM - 48对苯羟化反应具有一定活性 ,苯酚选择性高于80 % ,且随表面Ti含量增加 ,苯转化率和苯酚选择性提高。反应后催化剂的孔结构、比表面及孔径分布未受到影响 。Ti-containing MCM-48 materials were prepared by grafting Ti onto the surface of MCM-48.The structural characteristics of catalysts were studied by XRD,N 2 adsorption-desorption isotherms,XPS and AAS techniques.The results show that the materials possess well-ordered long-range structure and pore structure with specific surface area higher than 950 m 2·g -1 and narrow distribution of pore diameters.Ti-grafted MCM-48 materials were used as the catalyst for hydroxylation of benzene and their catalytic performance and stability were investigated.The results show that Ti-grafted MCM-48 exhibits good activity to the hydroxylation of benzene and also high selectivity for phenol.The conversion of benzene and selectivity for phenol increase with increasing Ti content. The specific surface area and pore diameter distribution exhibit no change after the hydroxylation reaction, while the local structure of Ti centers and long-range structure of MCM-48 change slightly.The change in the local structure of Ti centers results in partial deactivation of Ti-grafted MCM-48 catalyst.

关 键 词：钛 接枝 MCM-48 苯 羟化反应 化学亲和选择性 化学稳定性 催化剂 

分 类 号：TQ241.11[化学工程—有机化工]