Synthesis of Pure Silica MWW Zeolite in Fluoride Medium by Using an Imidazolium-Based Long Dication

doi:10.1002/chem.201804973

	Synthesis of Pure Silica MWW Zeolite in Fluoride Medium by Using an Imidazolium-Based Long Dication
	Gomez-Hortiguela, Luis 3; Lu, Peng 1,2; Camblor, Miguel A.1
刊名	CHEMISTRY-A EUROPEAN JOURNAL
	2019-01-28
卷号	25 期号:6 页码:1561-1572
关键词	density functional calculations fluoride media molecular mechanics structure directing agent zeolites
ISSN号	0947-6539
DOI	10.1002/chem.201804973
通讯作者	Camblor, Miguel A.(macamblor@icmm.csic.es)
英文摘要	As the spacer length in 1,2-dimethylimidazolium-based dications increases beyond a specific point (six methylene units), they fail in structure-directing towards STW zeolites in any synthetic conditions. These dications can instead produce, under fluoride concentrated conditions, either BEA [in the case of the eight-methylene-unit structure-directing agent (SDA)] or MWW (ten methylene units) zeolites. For any length of the dication, the default zeolite (MTW) is a relatively dense zeolite containing a unidimensional channel, whereas the zeolite demanding most specificity (STW, BEA or MWW) is more porous, affording a larger concentration of the dication to be occluded. This work provides the first reported fluoride synthesis of pure silica MWW zeolites. Charge balance of the organic dications in this zeolite was achieved by combining "structural" silanolates, regular "connectivity defects" and occluded fluoride. Molecular mechanics calculations showed a perfect fit of the decamethylenebis(dimethylimidazolium) dication in the sinusoidal intralayer pore system of MWW. The calculations showed also that the dication is able to stabilize the interlayer space without disturbing the hydrogen-bonding system that holds the layers together in the as-made material. The F-19 magic-angle spinning (MAS) NMR presented two distinct resonances at -71 and -83 ppm, which, on the basis of DFT calculations, we tentatively assigned to fluoride occluded in [4(6)6(2)] and [4(1)5(2)6(2)] cages of the MWW structure, respectively. The same DFT study determines a different chemical shift of one methyl C-13 nuclear magnetic resonance according to the imidazolium ring residing in the sinusoidal channels or in the large cup cavities, thus explaining an experimentally observed splitting of that resonance.
资助项目	Spanish Ministry of Economy and Competitiveness[MAT2015-71117-R] ; Spanish Ministry of Economy and Competitiveness[MAT2016-77496-R] ; China Scholarship Council (CSC) ; Centro Tecnico Informatico-CSIC
WOS关键词	STRUCTURE DIRECTION ; NMR PARAMETERS ; MCM-22 ; PRECURSOR ; ALUMINUM ; SYSTEMS
WOS研究方向	Chemistry
语种	英语
出版者	WILEY-V C H VERLAG GMBH
WOS记录号	WOS:000457477100026
资助机构	Spanish Ministry of Economy and Competitiveness ; Spanish Ministry of Economy and Competitiveness ; China Scholarship Council (CSC) ; China Scholarship Council (CSC) ; Centro Tecnico Informatico-CSIC ; Centro Tecnico Informatico-CSIC ; Spanish Ministry of Economy and Competitiveness ; Spanish Ministry of Economy and Competitiveness ; China Scholarship Council (CSC) ; China Scholarship Council (CSC) ; Centro Tecnico Informatico-CSIC ; Centro Tecnico Informatico-CSIC ; Spanish Ministry of Economy and Competitiveness ; Spanish Ministry of Economy and Competitiveness ; China Scholarship Council (CSC) ; China Scholarship Council (CSC) ; Centro Tecnico Informatico-CSIC ; Centro Tecnico Informatico-CSIC ; Spanish Ministry of Economy and Competitiveness ; Spanish Ministry of Economy and Competitiveness ; China Scholarship Council (CSC) ; China Scholarship Council (CSC) ; Centro Tecnico Informatico-CSIC ; Centro Tecnico Informatico-CSIC
内容类型	期刊论文
源URL	[http://cas-ir.dicp.ac.cn/handle/321008/166142]
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
通讯作者	Camblor, Miguel A.
作者单位	1.CSIC, ICMM, C Sor Juana Ines de la Cruz 3, Madrid 28049, Spain 2.Chinese Acad Sci, Dalian Natl Lab Clean Energy, Dalian Inst Chem Phys, Zhongshan Rd, Dalian 116023, Peoples R China 3.CSIC, ICP, C Marie Curie 2, Madrid 28049, Spain
推荐引用方式 GB/T 7714	Gomez-Hortiguela, Luis,Lu, Peng,Camblor, Miguel A.. Synthesis of Pure Silica MWW Zeolite in Fluoride Medium by Using an Imidazolium-Based Long Dication[J]. CHEMISTRY-A EUROPEAN JOURNAL,2019,25(6):1561-1572.
APA	Gomez-Hortiguela, Luis,Lu, Peng,&Camblor, Miguel A..(2019).Synthesis of Pure Silica MWW Zeolite in Fluoride Medium by Using an Imidazolium-Based Long Dication.CHEMISTRY-A EUROPEAN JOURNAL,25(6),1561-1572.
MLA	Gomez-Hortiguela, Luis,et al."Synthesis of Pure Silica MWW Zeolite in Fluoride Medium by Using an Imidazolium-Based Long Dication".CHEMISTRY-A EUROPEAN JOURNAL 25.6(2019):1561-1572.