离子液体功能化有序介孔SBA-15孔壁定域化磷钨酸催化活性中心构建及其催化性能  

Preparation and Catalytic Performance of Phosphotungstic Acid Active Sites Supported on Periodic Mesoporous Organosilica of SBA-15

作　　者：刘成[1] 谭蓉[1] 孙文庆[1] 银董红[1,2] 

机构地区：[1]湖南师范大学精细催化合成研究所,湖南长沙410081 [2]湖南中烟工业有限责任公司技术研发中心,湖南长沙410014

出　　处：《催化学报》2012年第6期1032-1040,共9页

基　　金：国家自然科学基金(20973057;21003044);湖南省自然科学基金(10JJ6028)~~

摘　　要：采用溶胶-凝胶法合成了一种桥键嵌入型双咪唑离子液体功能化介孔硅基材料(Bis-PImBr-PMO-SBA-15),然后离子交换将Keggin型磷钨酸负载于其上,制备了PW-Bis-PImBr-PMO-SBA-15催化剂,并运用X射线衍射、N2吸附-脱附、透射电子显微镜、傅里叶变换红外光谱和热重分析等手段对其进行表征.结果表明,该催化剂具有SBA-15分子筛的有序六方孔道结构,且负载后的磷钨酸阴离子仍保持其完整的Keggin结构.在以水为溶剂,30%H2O2为氧化剂的苯甲醇氧化反应中,该催化剂表现出比均相的或负载于SBA-15表面的Keggin型HPW更高的催化活性,苯甲醇转化率和苯甲醛选择性分别可达95%和94%.离子液体的咪唑阳离子可调节磷钨酸阴离子的氧化-还原性能,从而有利于提高催化剂的催化活性..A functionalized periodic mesoporous organosilica（PMO）,Bis-PImBr-PMO-SBA-15,incorporated with bridging bis-imidazolium ionic liquid moieties was synthesized via a sol-gel procedure.Keggin-type 12-phosphotungstic acid（H3PW12O40？ xH2O） was immobilized onto Bis-PImBr-PMO-SBA-15 by the way of anion-exchange,which provided the mesoporous organosilica-supported Keggin-type 12-tungstophosphate catalyst（PW-Bis-PImBr-PMO-SBA-15）.X-ray diffraction,N2 adsorption-desorption,transmission electron microscopy,Fourier transform infrared spectroscopy,and thermal analysis results showed that both Bis-PImBr-PMO-SBA-15 and PW-Bis-PImBr-PMO-SBA-15 maintained the typical characteristics of the mesoporous material,and the Keggin-structure of the 12-phosphotungstate anion was intact after immobilization.The catalytic performance of PW-Bis-PImBr-PMO-SBA-15 in the selective oxidation of benzyl alcohol by 30% H2O2 was investigated.The PW-Bis-PImBr-PMO-SBA-15 showed higher catalytic activity than bulk HPW or siliceous SBA-15-supported Keggin-type 12-tungstophosphate catalyst（HPW/SBA-15）,the conversion of benzyl alcohol and the selectivity to benzaldehyde were as high as 95% and 94%,respectively.The bis-imidazolium cations were thought to mediate the redox behavior of the Keggin PW12 anions,which in turns enhanced the activity and stability of the catalyst.

关 键 词：Keggin型12-磷钨酸 离子液体 周期性介孔有机硅 SBA-15分子筛 苯甲醇 催化氧化 过氧化氢 

分 类 号：O643.32[理学—物理化学]