Methane dehydroaromatization over Mo/HZSM-5 catalysts in the absence of oxygen: effects of silanation in HZSM-5 zeolite
文献类型:期刊论文
作者 | Liu, HM; Li, Y; Shen, WJ; Bao, XH; Xu, YD |
刊名 | catalysis today
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出版日期 | 2004-09-01 |
卷号 | 93-5页码:65-73 |
关键词 | methane dehydroaromatization Mo/HZSM-5 silanation Bronsted acid sites |
英文摘要 | teos as the exotic silicon source was used to modify hzsm-5 zeolite by chemical vapor deposition (cvd) in a vapor phase flow system. mo/hzsm-5 catalysts prepared by using silicon-modified zeolite showed higher activity and stability than those prepared by using non-modified hzsm-5 zeolite in methane dehydro-aromatization (mda) under non-oxidative conditions. the effect of silanation on the acid sites and the interaction between the mo species and the acid sites have been studied by using ft-ir, nh3-tpd and h-1 mas nmr. the exotic silicon species not only selectively covered and eliminated almost all of the bronsted acid sites on the external surface of hzsm-5 zeolite, but also affected the internal bronsted acid sites, which are close to the channel openings. this results in an obvious decrease in the number of bronsted acid sites per unit cell. in the mda reaction, the bronsted acid sites provided active sites not only for the polymerization and aromatization of the active intermedia, but also for the formation of carbonaceous deposits, which is a crucial factor leading to the deactivation of mo/hzsm-5 catalyst. only a small fraction of bronsted acid sites, ca. 0.6 per unit cell, was required to accomplish the aromatization, and the superfluous free bronsted acid sites would cause severe carbonaceous deposits under non-oxidative condition at a temperature as high as 973 k. (c) 2004 elsevier b.v. all rights reserved. |
WOS标题词 | science & technology ; physical sciences ; technology |
类目[WOS] | chemistry, applied ; chemistry, physical ; engineering, chemical |
研究领域[WOS] | chemistry ; engineering |
关键词[WOS] | temperature-programmed desorption ; nuclear-magnetic-resonance ; ion zsm-5 zeolites ; mo-based catalysts ; x-ray-absorption ; acid sites ; dehydro-aromatization ; chemical-vapor ; mas nmr ; nonoxidative conditions |
收录类别 | ISTP ; SCI |
语种 | 英语 |
WOS记录号 | WOS:000223973200009 |
公开日期 | 2015-11-10 |
源URL | [http://159.226.238.44/handle/321008/139320] ![]() |
专题 | 大连化学物理研究所_中国科学院大连化学物理研究所 |
作者单位 | Chinese Acad Sci, Dalian Inst Chem Phys, State Key Lab Catalysis, Dalian 116023, Peoples R China |
推荐引用方式 GB/T 7714 | Liu, HM,Li, Y,Shen, WJ,et al. Methane dehydroaromatization over Mo/HZSM-5 catalysts in the absence of oxygen: effects of silanation in HZSM-5 zeolite[J]. catalysis today,2004,93-5:65-73. |
APA | Liu, HM,Li, Y,Shen, WJ,Bao, XH,&Xu, YD.(2004).Methane dehydroaromatization over Mo/HZSM-5 catalysts in the absence of oxygen: effects of silanation in HZSM-5 zeolite.catalysis today,93-5,65-73. |
MLA | Liu, HM,et al."Methane dehydroaromatization over Mo/HZSM-5 catalysts in the absence of oxygen: effects of silanation in HZSM-5 zeolite".catalysis today 93-5(2004):65-73. |
入库方式: OAI收割
来源:大连化学物理研究所
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