The synergic effect between Mo species and acid sites in Mo/HMCM-22 catalysts for methane aromatization

被引：37

作者：

Ma, D ^{[1
]}

Zhu, QJ ^{[1
]}

Wu, ZL ^{[1
]}

Zhou, DH ^{[1
]}

Shu, YY ^{[1
]}

Xin, Q ^{[1
]}

Xu, YD ^{[1
]}

Bao, XH ^{[1
]}

机构：

[1] Chinese Acad Sci, Dalian Inst Chem Phys, State Key Lab Catalysis, Dalian 116023, Peoples R China

来源：

PHYSICAL CHEMISTRY CHEMICAL PHYSICS | 2005年 / 7卷 / 16期

关键词：

D O I：

10.1039/b502794b

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The acid properties of Mo/HMCM-22 catalyst, which is the precursor form of the working catalyst for methane aromatization reaction, and the synergic effect between Mo species and acid sites were studied and characterized by various characterization techniques. It is concluded that Bronsted and Lewis acidities of HMCM-22 are modified due to the introduction of molybdenum. We suggest a monomer of Mo species is formed by the exchange of Mo species with the Bronsted acid sites. On the other hand, coordinate unsaturated sites (CUS) are suggested to be responsible for the formation of newly detected Lewis acid sites. Computer modelling is established and coupling with experimental results, it is then speculated that the effective activation of methane is properly accomplished on Mo species accommodated in the 12 MR supercages of MCM-22 zeolite whereas the Bronsted acid sites in the same channel system play a key role for the formation of benzene. A much more pronounced volcano-typed reactivity curve of the Mo/HMCM-22 catalysts, as compared with that of the Mo/HZSM-5, with respect to Mo loading is found and this can be well understood due to the unique channel structure of MCM-22 zeolite and synergic effect between Mo species and acid sites.

引用

页码：3102 / 3109

页数：8

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