负载型Lewis酸催化剂的制备与应用进展

Progress on Preparation and Application of Supported Lewis Acid Catalysts

综述了以蒙脱土、γ-A l2O3、S iO2、聚合物以及分子筛为载体,用气相沉积和液相浸渍法负载A lC l3等Lew is酸制备负载型催化剂的方法。分析了负载型催化剂酸中心的结构和形成机理,比较了介孔分子筛在负载A lC l3前后对芳烃择形催化反应的情况。众多的研究结果表明,与A lC l3等Lew is酸相比,负载型A lC l3催化剂可以显著地提高芳烃烷基化产物的对位选择性,A lC l3负载改性是制备环境友好催化剂及均相Lew is酸催化剂多相化的有效手段。

The preparation and catalytic properties of catalysts with AlCl3 or other Lewis acids supported on montmorillonite, γ -Al2O3, SiO2, polymer or molecular sieve by chemical vapor deposition and liquid impregnation were reviewed. Structure and formation mechanism of acidic sites on supported catalysts were discussed. The catalytic performances for aromatic shape - selective reactions over AlCl3 supported on mesoporous molecular sieve with or without modification were compared. Many research works showed that the active sites of Lewis or Brtinsted acid were formed through reaction of AlCl3 with Si-OH on SiO2 or molecular sieve to form （-O-） AlCl2, which was characterized by means of IR. In comparison with Lewis acids such as AlCl3, para - product selectivity in aromatic alkylation over AlCl3 supported catalyst evidently increased. AlCl3 immobilized on supports was effective media for preparation of environmentally friendly catalysts and transformation of homogeneous catalysis to heterogeneous. Regeneration of deactivated catalyst could satisfactorily be accomplished by treating the used catalyst with a saturated solution of AlCl3 in CCl4 either in situ or not.