【摘要】 通过嫁接的方法合成了AlSBA15介孔分子筛,用X射线衍射、透射电子显微镜、低温N2吸附和NH3程序升温脱附等方法进行了表征,并研究了其在苯酚叔丁基化反应中的催化性能.结果表明,AlSBA15保持了母体SBA15高度有序的六方介孔结构,具有较强的酸性,且在苯酚叔丁基化反应中表现出比AlMCM41更好的催化活性和2,4二叔丁基苯酚选择性.更多还原

【Abstract】 Mesoporous Al-SBA-15 was successfully synthesized by post-synthesis grafting Al atoms on parent siliceous SBA-15. Both SBA-15 and Al-SBA-15 with different Si/Al ratios were characterized by powder X-ray diffraction, transmission electron microscopy, and N₂ adsorption-desorption methods. The analytic results show that the hexagonal p6mm mesostructure of parent siliceous SBA-15 is maintained very well in Al-SBA-15. NH₃ temperature-programmed desorption result indicates that Al-SBA-15 has both medium and strong acid sites. During the alkylation of phenol with tert-butanol, the Al-SBA-15 catalyst displays higher conversion of phenol and selectivity for 2,4-di-tert-butyl phenol （2,4-DTBP） than traditional Al-MCM-41 catalyst. At the reaction temperature of 145 ℃, a high phenol conversion of 75.2% and 2,4-DTBP selectivity of 31.3% over Al-SBA-15 are observed, but those over Al-MCM-41 are only 61.3% and 13.4%, respectively. Due to the large pore size （about 9 nm） which is beneficial to the effective diffusion of reactants and products, obvious catalyst deactivation of Al-SBA-15 is not observed even after reaction for 5 h.更多还原