摘要
用IR和ITPD技术研究了H(Al)ZSM-5、H(Ga)ZSM-5和H(Fe)ZSM-5杂原子分子筛的表面酸性。结果表明,这些分子筛表面既存在B酸中心,也存在L酸中心,但是就两种酸的表面浓度比值CL/CB而言,H(Ga)ZSM-5和H(Fe)ZSM-5要比H(Al)ZSM-5高得多。在十五烷裂解时,L酸中心起的作用可能更大。
The surface acidities and catalytic activities of some trivalent heteroatom-containing H(M)ZSM-5 (M=A1, Ga, Fe) zeolite have been studied by means of TPD, IR and cracking of n-pentadecane.The results indicate that Bronsted and Lewis acidic sites are present in these zeolites but the CL/CB on the surfaces of H(Ga)ZSM-5 and H(Fe)ZSM-5 are more higher than that on the surface of H(Aj)ZSM-5. Besides, there exist in the order of the acidic strength H(Al)ZSM-5>H(Ga)ZSM-5>H(Fe)ZSM-5. Cracking activities have been found to be dependent on the heteroatom in the framework of the zeolite. The normalized activity and the selectivity of gas-oil increase in the order as H(Ga)ZSM-5>H(Al)ZSM-5>H(Fe)ZSM-5. These results suggest that the Lewis acidic site play an important part in the cracking of n-pentadecane.
作者
蒋大振
肖丰收
刘子阳
徐如人
Jiang Dazhen;Xiao Fengshou;Liu Ziyang;Xu Ruren(Department of Chemistry,Jijin University,Changchun)
出处
《高等学校化学学报》
SCIE
EI
CAS
1988年第5期475-478,共4页
Chemical Journal of Chinese Universities
关键词
杂原子分子筛
表面酸性
裂化
Heteroatom zeolites
Surface acid
Cracking
作者简介
联系人:蒋大振。
