HPW/Al2O3催化剂的制备、表征及催化四氢呋喃聚合的研究

Preparation,Characterization and Catalytic Performance of HPW/Al_2O_3 for THF Polymerization

采用溶胶-凝胶法结合超临界流体干燥技术制备了Al2O3气凝胶载体,以浸渍法制得Al2O3气凝胶负载磷钨酸固体酸催化剂（HPW/Al2O3）。利用N2吸附-脱附、X射线粉末衍射（XRD）、NH3程序升温脱附（NH3-TPD）、傅立叶变换红外光谱（FTIR）、吡啶吸附红外光谱（Py-IR）等手段对HPW/Al2O3催化剂的织构、结构、表面性质等进行了表征,并考察了该催化剂在四氢呋喃聚合反应中的催化性能。结果表明,HPW/Al2O3催化剂负载量在50%~70%能较好地保留HPW的Keggin结构,具有强的Br nsted酸性特征,催化剂的酸量与酸强度随HPW负载量的提高呈递增趋势,而聚合物的收率及相对分子质量（以下简称分子量）与催化剂的酸量间存在线性关系,酸量越大,收率越高,分子量越低。

A series of HPW/Al2O3 solid acid catalyst with loading from 10% to 70% was synthesized.These catalysts were characterized by N2adsorption-desorption,XRD,NH3-TPD,FTIR spectroscopy and Py-IR spectroscopy.These above investigations indicated that HPW kept its Keggin type structure in the loading range of 50%～70%.The catalysts were the strong Brnsted acid and their total acidity increased with the laoding of HPW.The catalytic activities of these catalysts were evaluated by carrying out the polymerization of tetrahydrofuran（THF）.The results indicated that the higher acidic catalyst led to the higher yield of the polymer,yet with the lower average molecular weight of the polymer.