具有高活性六配位Ti物种的多级孔TS-1分子筛的合成及应用  

Synthesis and Application of Hierarchical Porous TS-1 Zeolite With Highly Active Six-Coordinated Ti Species

作　　者：肖昱 刘湛 余申 吕佳敏 杨晓宇 陈丽华[1] 苏宝连[1,2] XIAO Yu;LIU Zhan;YU Shen;L Jiamin;YANG Xiaoyu;CHEN Lihua;SU Baolian(State Key Laboratory of Advanced Technology for Materials Synthesis and Processing,Wuhan University of Technology,Wuhan 430070,China;Laboratory of Inorganic Materials Chemistry,University of Namur,Namur B-5000,Belgium)

机构地区：[1]武汉理工大学材料复合新技术国家重点实验室,湖北武汉430070 [2]那慕尔大学无机材料化学实验室,比利时那慕尔B-5000

出　　处：《石油学报（石油加工）》2024年第5期1157-1167,共11页Acta Petrolei Sinica(Petroleum Processing Section)

基　　金：国家自然科学基金项目(U20A20122)资助。

摘　　要：针对传统微孔TS-1分子筛孔道传输限制以及催化活性低的问题,采用碱腐蚀法制备了3种具有不同孔道结构以及不同钛物种分布的TS-1分子筛催化剂,采用扫描电子显微镜、透射电子显微镜、X射线衍射、N2吸附-脱附等温线、红外光谱、紫外-拉曼光谱、X射线光电子能谱和核磁共振等测试手段对其进行表征,并对其催化苯乙烯氧化反应性能进行评价。结果表明:与单独使用氢氧化钠或四丙基氢氧化铵溶液进行后处理相比,经过四丙基氢氧化铵和乙醇胺混合溶液处理的TS-1分子筛(TS-1-TE)具有最大的外比表面积和介孔体积,有效提高了客体分子的流通扩散效率;同时由于乙醇胺与钛物种的配位作用和四丙基氢氧化铵的重结晶作用,使得从骨架脱出的四配位钛物种能够以单核六配位Ti物种的形式存在于分子筛骨架中,有利于提高催化剂的活性;在温度60℃、压力0.116 MPa、反应时间6 h和催化剂用量50 mg的条件下,TS-1-TE催化剂表现出最高的反应活性,苯乙烯转化率为74.9%,六配位Ti原子转化数为197。In view of the limitation of channel transport in the traditional microporous TS-1 zeolite and the problem of low catalytic activity,three kinds of TS-1 zeolite catalysts with different channel structures and titanium species distribution patterns were prepared by alkali corrosion method,and further characterized by SEM,TEM,XRD,N_(2)adsorption-desorption isotherm,FT-IR,UV-Raman,XPS and NMR;their catalytic performance for styrene oxidation reaction was also evaluated.The results show that compared with the post-treatment with sodium hydroxide(NaOH)or tetrapropylammonium hydroxide(TPAOH),TS-1 zeolite(TS-1-TE)treated with the mixed solution of TPAOH and ethanolamine(EOA)has the larger external specific surface area and mesoporous pore volume,which effectively improves the flow and diffusion efficiency of guest molecules.Meanwhile,owing to the coordination between EOA and titanium species as well as the recrystallization of TPAOH,the four-coordinated titanium species separated from the framework can exist in zeolite framework in the form of mononuclear six-coordinated titanium species;the framework is conducive to improving the activity of catalyst.Under the conditions of reaction temperature 60℃,reaction time 6 h,reaction pressure 0.116 MPa and catalyst dosage 50 mg,TS-1-TE catalyst shows the highest activity,the conversion rate of styrene is 74.9%,and the conversion number of six-coordinated titanium atoms is 197.

关 键 词：TS-1分子筛 重结晶 六配位Ti物种 多级孔 苯乙烯氧化 

分 类 号：O643.36[理学—物理化学]