Bi—Ce二元氧化物催化剂上丙烯氧化脱氢二聚的动力学与反应机理

丙烯在氧化物催化剂上氧化脱氢二聚反应的研究,文献上主要是在Bi-Sn系催化剂上进行的,不同研究者根据各自的结果,对这一步反应提出了两种不同的机理:一种认为是催化剂表面上吸附丙烯间的二聚(Langmuir-Hinshelwood型机)理;另一种认为是气相丙烯与吸附丙烯间的二聚(Eley-Rideal型机理).我们发现Bi-Ce二元氧化物显示出与Bi-

KINETICS OF OXIDATIVE DEHYDRODIMERZIZATION OF PROPYLENE OVER Bi-Ce BINARY OXIDE CATALYST

The kinetic study of the oxidative dehydrodimerization of propylene over the Bi-Ce oxidecatalyst showed that the dimer formation reaction is first order with respect to the partialpressure of propylene and is zero order with respect to that Of oxygen, while the formationof carbon dioxide is zeroth order and 0.35 order with respect to the partial pressure of pro-pylene and to that of oxygen, respectively. It is considered that the dimerization and thecomplete oxidation of propylene take place on different active sites patallelly and the coup-ling of propylene is the rate-determining step, which is a result of the reaction between agaseous propylene molecule and an adsorbed one on the catalyst surface (Eley-Ridsal type).