载体酸性对Mo/HZSM-5-Al_2O_3催化剂上烯烃歧化反应性能的影响

在固定床反应器上考察了Mo/HZSM-5-Al2O3催化剂上乙烯与2-丁烯歧化制丙烯反应的性能.结合X射线衍射、NH3程序升温脱附、吡啶吸附红外光谱、H2程序升温还原和程序升温氧化等表征结果发现,载体酸性的差异导致催化剂酸性和Mo物种落位方式不同.载体酸性较强时,催化剂积炭严重,反应稳定性差;载体酸性较弱时,Mo物种在分子筛孔道内以（Mo2O5）2＋团簇形式存在,而在Al2O3表面形成较多易还原的六配位Mo物种,催化活性低,并呈现出一定的诱导期;适中酸性的载体有利于Mo物种的分散和活化,表现出了最佳的歧化反应活性....

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Bibliographic Details
Published in催化学报 Vol. 32; no. 11; pp. 1747 - 1754
Main Author 张大洲 李秀杰 刘盛林 朱向学 辛文杰 谢素娟 曾蓬 徐龙伢
Format Journal Article
LanguageChinese
Published 2011
Subjects
HZSM-5分子筛
丁烯
丙烯
乙烯
歧化反应
氧化铝
载体酸性
Online AccessGet full text
ISSN0253-9837
1872-2067

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Summary:在固定床反应器上考察了Mo/HZSM-5-Al2O3催化剂上乙烯与2-丁烯歧化制丙烯反应的性能.结合X射线衍射、NH3程序升温脱附、吡啶吸附红外光谱、H2程序升温还原和程序升温氧化等表征结果发现,载体酸性的差异导致催化剂酸性和Mo物种落位方式不同.载体酸性较强时,催化剂积炭严重,反应稳定性差;载体酸性较弱时,Mo物种在分子筛孔道内以（Mo2O5）2＋团簇形式存在,而在Al2O3表面形成较多易还原的六配位Mo物种,催化活性低,并呈现出一定的诱导期;适中酸性的载体有利于Mo物种的分散和活化,表现出了最佳的歧化反应活性.
Bibliography:ZHANG Dazhou1,2, LI Xiujie1, LIU Shenglin1, ZHU Xiangxue1, XIN Wenjie1, XIE Sujuan1, ZENG Peng3, XU Longya1 1Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning, China 2Graduate University of Chinese Academy of Sciences, Beijing 100049, China 3China Huanqiu Contracting ＆ Engineering Corporation, Fushun 113006, Liaoning, China
ethene; butene; metathesis reaction; propene; support acidity; HZSM-5 zeolite; alumina
Mo/HZSM-5-Al2O3 catalyst samples, where the HZSM-5 had different Si/Al ratios （12, 42, and 213）, were prepared and evaluated in a fixed-bed reactor. Effects of support acidity changes on the catalytic performance of Mo/HZSM-5-Al2O3 in the metathesis of ethene and 2-butene to propene were investigated. NH3 temperature-programmed desorption and pyridine infrared spectra revealed that the differences in support acidity led to the different anchoring modes of Mo species on the composite supports. Quick deactivation phenomena were observed on Mo/HZSM-5-Al2O3 （Si/Al = 12）
ISSN:0253-9837
1872-2067