Structure and acidity of Mo/H-MCM-22 catalysts studied by NMR spectroscopy

	Structure and acidity of Mo/H-MCM-22 catalysts studied by NMR spectroscopy
	Huang, SJ ; Zhao, Q ; Chen, WH ; Han, XW ; Bao, XH ; Lo, PS ; Lee, HK ; Liu, SB
刊名	catalysis today
	2004-10-20
卷号	97 期号:1 页码:25-34
关键词	Mo/MCM-22 bifunctional catalyst NMR porosity acidity
产权排序	2;2
英文摘要	a comprehensive study on physical and chemical properties of mo/mcm-22 bifunctional catalysts has been made by using combined analytic and spectroscopic techniques, such as adsorption, elemental analysis, and xe-129 and p-31 nmr of adsorbed trialkylphosphine oxide probe molecules. samples prepared by the impregnation method with mo loadings ranging from 2-10 wt.% have been examined and the results are compared with that obtained from samples prepared by mechanical mixing using moo3 or mo2c as agents. sample calcination treatment is essential in achieving a well-dispersed metal species in mo/mcm-22. it was found that, upon initial incorporation, the mo species tend to inactivate both bronsted and lewis sites locate predominantly in the supercages rather than the 10-membered ring channels of mcm-22. however, as the mo loading exceeds 6 wt.%, the excessive mo species tend to migrate toward extracrystalline surfaces of the catalyst. a consistent decrease in concentrations of acid sites with increasing mo loading < 6 wt.% was found, especially for those with higher acid strengths. upon loading of mo > 6 wt.%, further decreases in both bronsted and lewis acidities were observed. these results provide crucial supports for interpreting the peculiar behaviors previously observed during the conversion of methane to benzene over mo/mcm-22 catalyst under non-oxidative conditions, in which an optimal performance was achieved with a mo loading of 6 wt.%. the effects of mo incorporation on porosity and acidity features of the catalyst are discussed. (c) 2004 published by elsevier b.v.
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]	solid-state nmr ; methane dehydro-aromatization ; xe-129 nmr ; p-31 nmr ; trimethylphosphine oxide ; probe molecule ; zeolites ; sites ; xenon ; quantification
收录类别	ISTP ; SCI
原文出处	true
语种	英语
WOS记录号	WOS:000224784400004
公开日期	2010-11-30
内容类型	期刊论文
源URL	[http://159.226.238.44/handle/321008/82059]
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	1.Acad Sinica, Inst Atom & Mol Sci, Taipei 106, Taiwan 2.Chinese Acad Sci, Dalian Inst Chem Phys, Dalian, Peoples R China 3.Chinese Cultural Univ, Inst Mat Sci & Mfg, Taipei 111, Taiwan
推荐引用方式 GB/T 7714	Huang, SJ,Zhao, Q,Chen, WH,et al. Structure and acidity of Mo/H-MCM-22 catalysts studied by NMR spectroscopy[J]. catalysis today,2004,97(1):25-34.
APA	Huang, SJ.,Zhao, Q.,Chen, WH.,Han, XW.,Bao, XH.,...&Liu, SB.(2004).Structure and acidity of Mo/H-MCM-22 catalysts studied by NMR spectroscopy.catalysis today,97(1),25-34.
MLA	Huang, SJ,et al."Structure and acidity of Mo/H-MCM-22 catalysts studied by NMR spectroscopy".catalysis today 97.1(2004):25-34.