Al2（SO4）3／SiO2催化甲醇脱水合成二甲醚

采用浸渍法制备了不同负载量的Al2（SO4）3／SiO2催化剂．使用BET、XRD、FT—IR、异丙醇探针反应、NH3吸附量热和NH3吸附红外等手段对催化剂进行了表征，并测试了其在甲醇脱水合成二甲醚反应中的活性．BET、XRD和FT-IR结果表明，载体SiO2的表面积较高，随着Al2（SO4）3负载量的增加，样品的表面积逐渐降低，当Al2（SO4）3负载量高于20％时，样品表面开始出现晶相Al2（SO4）3．NH3吸附量热和NH3吸附红外结果表明，载体SiO2的酸性很弱，负载了Al2（SO4）3后，样品酸性大大增强，且酸性随着Al2（SO4）3负载量的增加先增强后减弱．样品表面同时存在B酸中心和L酸中心，但以B酸中心为主．Al2（SO4）3负载量为3％的样品的表面酸性最强，因而在甲醇脱水反应中表现出最高的反应活性，533K，甲醇转化率为83．5％，二甲醚选择性100％．

Dehydration of Methanol to Dimethyl Ether over Al2(SO4)3/SiO2 Catalysts

The Al2(SO4)3/SiO2 catalysts were prepared via an incipient wetness impregnation method.The physical and chemical properties,in especial the surface acidity of the catalysts were characterized by the techniques of BET,XRD,FT-IR,isopropanol probe reaction,microcalorimetry and FT-IR for NH3 adsorption.The catalytic activities of the catalysts were evaluated in the reaction of methanol dehydration to dimethyl ether.The results from BET,XRD and FT-IR verified that the specific surface areas of the supported cat...