改性对β沸石表面酸性及丙烯水合醚化反应性能的影响

采用浸渍法和离子交换法，制备出一系列改性β沸石催化剂，考察了改性剂对β沸石表面酸性及丙烯水合醚化反应性能的影响。结果表明：硼、锌、铝改性可以提高β沸石的L酸中心，磷、镧、铈改性后β沸石的B酸中心增加。催化剂的B酸和L酸中心与丙烯转化率和异丙醚选择性之间存在着一定的对应关系：B酸量增加有利于提高丙烯转化率，L酸量增加有利于提高异丙醚的选择性。合适的B／L酸比例是催化剂同时具有高活性和高异丙醚选择性的关键。

EFFECTS OF Hβ MODIFICATION ON ACIDITY AND ACTIVITY FOR PROPENE HYDRATION ETHERIFICATION

A series of modified zeolite beta were prepared by means of impregnation and ion exchange The effects of different modifiers on acidity and activity for propene hydration etherification were investigated The L acid sites of zeolites beta which modified by boron, zinc and aluminium were increased,while the B acid sites were increaced when it was modified by phosphorus and rare earth A corresponding relation between the B, L acid sites and the conversion of propene as well as the selectivity of diisopropyl ether is exist The reaction converting propene and water into iospropanol is basic reaction, the produced isopropanol can carry out further reactions of innermolecular dehydration, intermolecular dehydration, and etherification with propene The conversion of propene increases along with the increase of B acid sites, while the selectivity of diisopropyl ether increases along with the increase of L acid sites A suitable ratio of B/L acid is a key factor for preparing a catalyst with high activity and selectivity for propene hydration etherification