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	Direct synthesis and structural characteristics of ordered SBA-15 mesoporous silica containing tungsten oxides and tungsten carbides
	Hu, Linhua; Ji, Shengfu; Jiang, Zheng; Song, Huanling; Wu, Pingyi; Lint, Qianqian
刊名	JOURNAL OF PHYSICAL CHEMISTRY C
	2007-10-25
卷号	111期号:42页码:15173-15184
关键词	molecular-sieves catalytic application selective oxidation mo2c/al2o3 catalyst templated synthesis metal carbides synthesis gas surface-area molybdenum methane
ISSN号	1932-7447
其他题名	J. Phys. Chem. C
中文摘要	A series Of WO3-SBA-15 materials with different Si/W ratios have been hydrothermally synthesized using tetraethyl orthosilicate (TEOS) as silica precursor, ammonium paratungstate as tungsten precursor, and EO20PO70EO20 (P] 23) as structure-directing reagent. After temperature-programmed carburization (TPC) in flowing CH4/H-2 (20/80 v/v mixture), the materials were converted to the corresponding WxC-SBA- 15 materials. The structure of the oxide and carbide materials has been characterized using X-ray diffraction (XRD), X-ray fluorescence (XRF), nitrogen adsorption -desorption measurements, Si-29 magic-angle spinning (MAS) NMR spectroscopy, Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), and thermogravimetric and differential scanning calorimetric analysis (TG-DSC) measurements. The results show that after hydrothermal synthesis using different amounts of tungsten and subsequent carburization, the materials retain the mesopore structure of SBA- 15. When Si/W = 30-15, the majority of the tungsten is dispersed in the channels of SBA-15 with the remainder being incorporated into the framework of SBA-15 with the formation of Si-O-W bonds. The tungsten carbide exists as a single W2C phase after carburization. At higher tungsten content (Si/W = 7.5), the amount of tungsten in the framework of SBA-15 increases with the formation of both Si-O-W bonds and W-O-W bonds. The tungsten carbide formed after carburization exists as a mixture Of W2C and WC phases. A model for the distribution of tungsten in SBA-15 is proposed involving three different tungsten species: alpha-W inside SBA-15 channels, beta-W embedded in the internal surfaces of the SBA- 15 channels, and gamma-W inside the framework of SBA- 15. After temperature-programmed carburization, alpha-W sites are transformed into W2C, whereas beta-W sites afford WC; in contrast, gamma-W sites show little change after carburization.
英文摘要	A series Of WO3-SBA-15 materials with different Si/W ratios have been hydrothermally synthesized using tetraethyl orthosilicate (TEOS) as silica precursor, ammonium paratungstate as tungsten precursor, and EO20PO70EO20 (P] 23) as structure-directing reagent. After temperature-programmed carburization (TPC) in flowing CH4/H-2 (20/80 v/v mixture), the materials were converted to the corresponding WxC-SBA- 15 materials. The structure of the oxide and carbide materials has been characterized using X-ray diffraction (XRD), X-ray fluorescence (XRF), nitrogen adsorption -desorption measurements, Si-29 magic-angle spinning (MAS) NMR spectroscopy, Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), and thermogravimetric and differential scanning calorimetric analysis (TG-DSC) measurements. The results show that after hydrothermal synthesis using different amounts of tungsten and subsequent carburization, the materials retain the mesopore structure of SBA- 15. When Si/W = 30-15, the majority of the tungsten is dispersed in the channels of SBA-15 with the remainder being incorporated into the framework of SBA-15 with the formation of Si-O-W bonds. The tungsten carbide exists as a single W2C phase after carburization. At higher tungsten content (Si/W = 7.5), the amount of tungsten in the framework of SBA-15 increases with the formation of both Si-O-W bonds and W-O-W bonds. The tungsten carbide formed after carburization exists as a mixture Of W2C and WC phases. A model for the distribution of tungsten in SBA-15 is proposed involving three different tungsten species: alpha-W inside SBA-15 channels, beta-W embedded in the internal surfaces of the SBA- 15 channels, and gamma-W inside the framework of SBA- 15. After temperature-programmed carburization, alpha-W sites are transformed into W2C, whereas beta-W sites afford WC; in contrast, gamma-W sites show little change after carburization.
WOS标题词	Science & Technology ; Physical Sciences ; Technology
类目[WOS]	Chemistry, Physical ; Nanoscience & Nanotechnology ; Materials Science, Multidisciplinary
研究领域[WOS]	Chemistry ; Science & Technology - Other Topics ; Materials Science
关键词[WOS]	MOLECULAR-SIEVES ; CATALYTIC APPLICATION ; SELECTIVE OXIDATION ; MO2C/AL2O3 CATALYST ; TEMPLATED SYNTHESIS ; METAL CARBIDES ; SYNTHESIS GAS ; SURFACE-AREA ; MOLYBDENUM ; METHANE
收录类别	SCI
原文出处	://WOS:000250438900008
语种	英语
WOS记录号	WOS:000250438900008
公开日期	2013-10-15
内容类型	期刊论文
版本	出版稿
源URL	[http://ir.ipe.ac.cn/handle/122111/3340]
专题	过程工程研究所_研究所（批量导入）
作者单位	1.Beijing Univ Chem Technol, State Key Lab Chem Resource Engn, Beijing 100029, Peoples R China 2.Chinese Acad Sci, Inst Proc Engn, State Key Lab Multi Phase Complex Syst, Beijing 100080, Peoples R China 3.Chinese Acad Sci, Lanzhou Inst Chem Phys, State Key Lab Oxo Synth & Select Oxidat, Lanzhou 730000, Peoples R China
推荐引用方式 GB/T 7714	Hu, Linhua,Ji, Shengfu,Jiang, Zheng,et al. Direct synthesis and structural characteristics of ordered SBA-15 mesoporous silica containing tungsten oxides and tungsten carbides[J]. JOURNAL OF PHYSICAL CHEMISTRY C,2007,111(42):15173-15184.
APA	Hu, Linhua,Ji, Shengfu,Jiang, Zheng,Song, Huanling,Wu, Pingyi,&Lint, Qianqian.(2007).Direct synthesis and structural characteristics of ordered SBA-15 mesoporous silica containing tungsten oxides and tungsten carbides.JOURNAL OF PHYSICAL CHEMISTRY C,111(42),15173-15184.
MLA	Hu, Linhua,et al."Direct synthesis and structural characteristics of ordered SBA-15 mesoporous silica containing tungsten oxides and tungsten carbides".JOURNAL OF PHYSICAL CHEMISTRY C 111.42(2007):15173-15184.

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