Solid-state MAS NMR studies on the hydrothermal stability of the zeolite catalysts for residual oil selective catalytic cracking

	Solid-state MAS NMR studies on the hydrothermal stability of the zeolite catalysts for residual oil selective catalytic cracking
	Zhuang, JQ; Ding, M; Gang, Y; Yan, ZM; Liu, XM; Liu, XC; Han, XW; Bao, XH; Peng, X; Liu, ZM
刊名	journal of catalysis
	2004-11-15
卷号	228 期号:1 页码:234-242
关键词	solid-state MAS NMR hydrothermal stability zeolites
产权排序	1;1
英文摘要	by using the solid-state mas nmr technique, the hydrothermal stabilities (under 100% steam at 1073 k) of hzsm-5 zeolites modified by lanthanum and phosphorus have been studied. they are excellent zeolite catalysts for residual oil selective catalytic cracking (rscc) processes. it was indicated that the introduction of phosphorus to the zeolite via impregnation with orthophosphoric acid led to dealumination as well as formation of different al species, which were well distinguished by al-27 3q mas nmr. meanwhile, the hydrothermal stabilities of the zeolites (p/hzsm-5, la-p/hzsm-5) were enhanced even after the samples were treated under severe conditions for a prolonged time. it was found that the si-o-al bonds were broken under hydrothermal conditions, while at the same time the phosphorous compounds would occupy the silicon sites to form (sio)(x)al(op)(4 - x) species. with increasing time, more silicon sites around the tetrahedral coordinated al in the lattice can be replaced till the aluminum is completely expelled from the framework. the existence of lanthanum can partially restrict the breaking of the si-o-al bonds and the replacement of the silicon sites by phosphorus, thus preventing dealumination under hydrothermal conditions. this was also proved by p-31 mas nmr spectra. (c) 2004 elsevier inc. all rights reserved.
WOS标题词	science & technology ; physical sciences ; technology
类目[WOS]	chemistry, physical ; engineering, chemical
研究领域[WOS]	chemistry ; engineering
关键词[WOS]	nuclear magnetic-resonance ; angle-spinning nmr ; multiple aluminum environments ; chemical-shift ; high-field ; zsm-5 zeolite ; acid sites ; al-27 mas ; heavy oil ; p-31
收录类别	SCI
原文出处	true
语种	英语
WOS记录号	WOS:000224756800024
公开日期	2010-11-30
内容类型	期刊论文
源URL	[http://159.226.238.44/handle/321008/82651]
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	Zhuang, JQ,Ding, M,Gang, Y,et al. Solid-state MAS NMR studies on the hydrothermal stability of the zeolite catalysts for residual oil selective catalytic cracking[J]. journal of catalysis,2004,228(1):234-242.
APA	Zhuang, JQ.,Ding, M.,Gang, Y.,Yan, ZM.,Liu, XM.,...&Liu, ZM.(2004).Solid-state MAS NMR studies on the hydrothermal stability of the zeolite catalysts for residual oil selective catalytic cracking.journal of catalysis,228(1),234-242.
MLA	Zhuang, JQ,et al."Solid-state MAS NMR studies on the hydrothermal stability of the zeolite catalysts for residual oil selective catalytic cracking".journal of catalysis 228.1(2004):234-242.