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	SBA-15负载β-Mg2V2O7催化剂的制备及其催化丙烷选择氧化脱氢的性能; Preparation of SBA-15-Supported β-Mg2V2O7 Catalysts and Their Properties in Oxidative Dehydrogenation of Propane
	张胜红 ; 张鸿鹏 ; 孙吉莹 ; 刘海超
	2010
关键词	丙烷 丙烯 氧化脱氢 焦钒酸镁 负载型催化剂 propane propene oxidative dehydrogenation magnesium pyrovanadate supported catalyst
英文摘要	以MgO修饰的SBA-15为载体,采用浸渍法制备了负载β-Mg2V2O7,催化剂,并运用X射线衍射、拉曼光谱、紫外-可见漫反射光谱和H2程序升温还原等技术对催化剂V中心的结构和还原性能进行了表征.结果表明,β-Mg2V2O7具有与α-Mg2V2O7相同的结构单元,但其催化丙烷氧化脱氢(ODH)反应的初始活性和初始选择性均低于后者.与体相β-Mg2V2O7相比,负载的β-Mg2V2O7上V中心分散度以及丙烷ODH反应活性和选择件更高,520℃时丙烷ODH反应的仞始活性提高了约20倍,丙烯仞始选择性也从休相的88.3%提高到94.1%,接近于α-Mg2V2O7(94.6%),并且在20%的丙烷转化率时也表现出相似的规律.这与表征催化剂选择性的两个木征动力学参数k1k2(丙炕初级ODH和燃烧反应速率常数之比)和k3k1(次级丙烯燃烧和初级丙烷ODH反应速率常数之比)反映出的规律一致.这些对体相和负载的Mg2V2O7催化剂催化丙烷ODH反应木征特性的认识将有助于设计合成更高效的Mg-V-O催化剂,如基于α-Mg2V2O7结构的高分散催化剂,以获得更高的内烷ODH反应活性和选择性.; beta-Mg(2)V(2)O(7)catalysts supported on MgO-modified SBA-15 with V surface density of 4.1-8.5 nm(-2) were synthesized by impregnation of the support with a pre-prepared aqueous solution of ammonium metavanadate, citric acid, and magnesium nitrate. The structure and reducibility of the catalysts were characterized by X-ray diffraction, Raman spectroscopy, diffuse reflectance UV-Vis spectroscopy, and temperature-programmed reduction in H-2. For oxidative dehydrogenation (ODH) of propane, bulk beta-Mg(2)V(2)O(7)phase was much less active and selective than alpha-Mg2V2O7 although they have the same dimeric tetrahedral VO4 units connected by bridging V-O-V bonds. Compared to the bulk phase, the greater accessibility of V sites on the supported beta-Mg2V2O7 catalysts led to an increase in not only the initial propane ODH rates by about 20 times but also the initial propene selectivity from 88.3 to 94.1%, as high as that for alpha-Mg2V2O7 (94.6%) that has been considered as the most selective Mg-V-O phase for propane ODH reactions. The selectivity results are consistent with those reflected by the two kinetic parameters, k(1)/k(2) and k(3)/k(1), which represent the ratios of the rate constants for primary propane ODH (k(1)) to propane combustion (k(2)) and that for secondary propene combustion (k(3)) to k(1). Such understanding on the intrinsic catalytic properties of the bulk and supported Mg2V2O7 catalyst provides useful information for design of new Mg-V-O-based catalysts, for example, dispersed alpha-Mg2V2O7 catalyst with high activity and selectivity for propane ODH reactions under mild conditions.; 国家自然科学基金; 国家重点基础研究发展计划; http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000287274100012&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701 ; SCI(E); 中文核心期刊要目总览(PKU); 中国科技核心期刊(ISTIC); 中国科学引文数据库(CSCD); 3; 11; 1374-1380; 31
语种	中文
出处	SCI ; 万方 ; http://d.g.wanfangdata.com.cn/Periodical_cuihuaxb201011012.aspx
出版者	催化学报
内容类型	其他
源URL	[http://hdl.handle.net/20.500.11897/81093]
专题	化学与分子工程学院
推荐引用方式 GB/T 7714	张胜红,张鸿鹏,孙吉莹,等. SBA-15负载β-Mg2V2O7催化剂的制备及其催化丙烷选择氧化脱氢的性能, Preparation of SBA-15-Supported β-Mg2V2O7 Catalysts and Their Properties in Oxidative Dehydrogenation of Propane. 2010-01-01.

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