负载杂多酸催化苯与丙烯合成异丙苯 Ⅱ. 负载杂多酸对苯与丙烯烷基化反应的催化作用

考察了负载杂多酸对苯与丙烯烷基化反应的催化性能,发现磷钨酸和硅胶是较好的活性组分和载体。以负载磷钨酸为催化剂,考察了负载量、活化温度、反应温度及丙烯分压对催化剂活性和选择性的影响。结果表明,负载量(质量分数)在20%～30%、活化温度200～300℃时,催化剂表现出较为理想的活性和选择性;反应温度低于70℃或丙烯分压高于0 3MPa时,活性受控于催化反应速率;反应温度高于90℃或丙烯分压低于0 3MPa时,活性受控于丙烯在苯中的溶解速率。

Synthesis of Cumene with Benzene and Propene Catalyzed by Supported-Heteropolyacids Ⅱ.Alkylation of Benzene with Propene over Supported-Heteropolyacids Catalysts

The catalytic properties of supported heteropolyacids catalysts for alkylation of benzene with propylene were investigated.The results showed that phosphotungstic acid(PW 12 ) and silica gel is an excellent active constituent and support for the catalysts.The effects of PW 12 loading,activation temperature,reaction temperature and partial pressure of propene on activity and selectivity of the supported phosphotungstic acid were studied .The results showed the catalysts exhibited excellent activity when PW 12 loading was between 20% and 30%,and the activation temperature was between 200 ℃ and 300 ℃?The catalytic activity depended on reaction velocity when the reaction temperature was below 70 ℃,or the partial pressure of propene was above 0 3 MPa; but if the former was higer than 90 ℃,or the latter was lower than 0 3 MPa,then the catalytic activity depended on the dissolution rate of propene in benzene.