【摘要】 为了探明 Pd-Y 沸石催化剂上乙烯双聚反应诱导期的成因和活性中心的本质,借助于真空静态循环反应装置和 ESR 考察了反应条件下 PdY 催化剂的活化机制。提出了乙烯双聚过程中催化剂的活化图式。即 Pd-Y 沸石的活化过程包括钯离子从体相向表相、从六方柱笼及β笼向超笼的迁移过程;包括迁移的 Pd²⁺被乙烯还原为 Pd⁺的过程;还包括乙烯与 Pd⁺配位形成活性中间体的过程。更多还原

【Abstract】 To ascertain the cause of the induction period in ethylene dimerization and the nature of the active sites on Pd-Y zeolite catalysts,the activation mechan-ism of Pd-Y catalyst has been investigated with a closed recirculation apparatusand ESR measurements.It is postulated that the activation process includes themigration of Pd²⁺ions from bulk to surface and from h.p.or sodalite cages tosupercages;the reduction of Pd²⁺ions to Pd⁺ ions by ethylene;the coordinationof ethylene molecules to Pd⁺ with formation of active intermediates.更多还原