SO_4^(2-)/ZrMCM-48和H-ZrMCM-48的制备与催化性能  

Synthesis and Catalytic Property of SO_4^(2-)/ ZrMCM-48and H-ZrMCM-48

作　　者：贾佳[1] 赵谦[1] 王国伟[1] 马艳[1] 田军[2] 姜廷顺[1] 

机构地区：[1]江苏大学化学化工学院,镇江212013 [2]绥化学院食品与制药工程学院,绥化152061

出　　处：《纳米技术与精密工程》2013年第5期396-401,共6页Nanotechnology and Precision Engineering

基　　金：江苏大学人才基金资助项目(12JDG106);黑龙江省教育厅科学技术研究资助项目(12511630)

摘　　要：以正硅酸乙酯为硅源、硫酸锆为锆源、十六烷基三甲基溴化铵为模板剂,在氟化物存在的条件下,120℃下水热法合成ZrMCM-48介孔分子筛.分别用H2SO4和NH4NO3对ZrMCM-48进行修饰,得到酸性的SO42-/ZrMCM-48和H-ZrMCM-48介孔分子筛.通过X射线衍射仪(XRD)、NH3-TPD、N2吸附-脱附、透射电子显微镜(TEM)等方法对所得样品进行表征,并通过苯酚与叔丁醇的烷基化反应考察其催化性能.结果表明:ZrMCM-48、SO42-/ZrMCM-48和H-ZrMCM-48都具有MCM-48典型的立方介孔结构.经H2SO4和NH4NO3修饰后得到的样品的介孔有序性下降.ZrMCM-48的弱酸中心较多,强酸中心相对缺乏;样品H-ZrMCM-48和SO42-/ZrMCM-48,除具有弱酸中心外,还有一定量的强酸中心,并且SO42-/ZrMCM-48比H-ZrMCM-48的强酸中心多.在相同的实验条件下,SO42-/ZrMCM-48催化剂的催化活性明显高于H-ZrMCM-48和ZrMCM-48,反应温度为140℃时,苯酚转化率高达91.6%.对于SO42-/ZrMCM-48催化剂,在低温时有利于选择性制备2,4-DTBP,高温时有利于选择性制备4-TBP.ZrMCM-48 mesoporous molecular sieve was hydrothermally synthesized at 120 % using tetra- ethyl orthosilicate （TEOS） as silica source, zirconium sulfate as Zr source and cetyhrimethyl ammonium bromide （CTAB） as template. The SO24-/ZrMCM-48 and H-ZrMCM-48 catalysts wee prepared by mod- ification with H2SO4 and NH4NO3. The resulting samples were characterized by X-ray diffraction （XRD） , NH3 temperature-programmed desorption （NH3-TPD） , N2 physical adsorption-desorption, and transmis- sion electron microscopy （TEM）. The catalytic activities of those catalysts were evaluated in the alkyla- tion reaction of phenol and tert-butyl alcohol. The results show that the ZrMCM-48 sample has a typical cubic mesoporous framework, the SO24-/ZrMCM-48 and H-ZrMCM-48 catalysts still maintained the cubic mesporous structure, but the mesoporous ordering decreased. NHa-TPD analysis results reveal that the ZrMCM-48 samples have a certain number of weak acid sites but lack strong acid sites ; The H-ZrMCM-48 andSO24-/ZrMCM-48 samples have both strong and weak acid sites, and the SO24-/ZrMCM-48 samplehas more strong acid sites than the H-ZrMCM48 sample. Under comparable condition, the catalytic ac- tivity of theSO24-/ZrMCM48 catalyst is much higher than that of the H-ZrMCM-48 and ZrMCM-48 cata- lysts. At the reaction temperature of 140 ℃, a maximum phenol conversion of 91.6% was obtained. With SO24-/ZrMCM-48, the 2,4-DTBP tends to be formed at lower reaction temperature, while the 4- TBP is likely to be formed at higher reaction temperature.

关 键 词：介孔分子筛 SO24- ZrMCM-48 H—ZrMCM-48 烷基化反应 催化性能 

分 类 号：O643.36[理学—物理化学]