摘要
采用In-situIR和TPD-ITD研究了二异丙苯(DIPB)、异丙苯(IPB)、苯和丙烯在改性β沸石催化剂上的吸附和反应。考察了1,3-DIPB和1,4-DIPB与苯烷基转移的反应性能、催化剂的酸性质和催化剂的稳定性。结果表明,1,3-DIPB与苯烷基转移反应主要按双分子反应SN2-1机理进行,而1,4-DIPB与苯主要按单分子反应SN1机理进行;1,3-DIPB和1,4-DIPB之间存在着异构化反应。改性β沸石催化剂失活原因是:(1)焦炭覆盖在部分酸性中心上,使得催化剂的活性下降;(2)烷基萘等相对分子质量较大、沸点较高的化合物沉积在催化剂的孔口或表面。
The adsorption and reaction of propylene benzene,isopropylbenzene (IPB) and diisopropylbenzene (DIPB) over modified β type zeolite catalyst were studied by using in situ IR and TPD ITD methods.The reaction performances,the acid property and the stability of catalyst were evaluated.It is proposed that the transalkylation reaction of 1,3 DIPB with benzene is conducted according to the SN 2 1 mechanism,while 1,4 DIPB with benzene according to the SN 1 mechanism.Isomerization reaction may take place between 1,3 and 1,4 DIPB.The reason for catalyst deactivation is suggested as (1) part of the active sites may be covered by coke and this directed to catalyst deactivation;(2)bigger moleculars,such as alkyl naphthalene etc.,may deposit in the pore or on the surface of the catalyst and this directed to pore blockage.
出处
《石油学报(石油加工)》
EI
CAS
CSCD
北大核心
1999年第3期77-82,共6页
Acta Petrolei Sinica(Petroleum Processing Section)
关键词
改性
沸石催化剂
二异丙苯
催化剂失活
苯
modified β zeolite catalyst, diisopropylbenzene,transalkylation, reaction mechanism, catalyst deactivation