Study on Alkylation of Benzene with Ethylene over βZeolite Catalyst by in situ IR
WANG Hai, DU Ying chun, CHEN Shu (Research Center for Chemical Engineering, Beijing Institute of Clothing Technology, Beijing 100029)
The alkylation of benzene with ethylene over β zeolite catalyst was studied by using in situ IR method at 120, 160, 200 ℃. Benzene or ethylbenzene and ethylene were injected sequentially or vice versa into in situ IR cell and the changes of IR spectra were investigated. The alkylation mechanism has been referred as follows: Adsorbed ethylene may reacts with adsorbed benzene or ethylbenzene. They are adsorbed competitively at the same kind of sites. Ethylene adsorbs more strongly than benzene and ethylbenzene. At lower temperature, such as 120～160 ℃, when the sites of catalyst are occupied by ethylene, benzene and ethylbenzene are hardly to be adsorbed at the sites, therefore alkylation can not take place. Adsorbed ethylene can react with each other, and replace adsorbed benzene and ethylbenzene, so reaction occurs. At 200 ℃, benzene and ethylbenzene can replace a part of adsorbed ethylene and reaction can take place. By comparison with the reaction of cumene with propylene, the reaction of ethylbenzene with ethylene takes place more difficult at the same temperature.
【CateGory Index】： O643.32