物理化学学报 >> 2002, Vol. 18 >> Issue (10): 916-919.doi: 10.3866/PKU.WHXB20021010

研究论文 上一篇    下一篇

NaBr/KY催化剂在甲苯氧化甲基化反应中的稳定性

周灵萍;李伟;陶克毅;李赫咺;李宣文   

  1. 北京大学化学与分子工程学院, 北京　100871;南开大学化学学院, 天津　300071
  • 收稿日期:2002-01-29 修回日期:2002-04-24 发布日期:2002-10-15
  • 通讯作者: 周灵萍 E-mail:zhou_ling_ping@hotmail.com

The Stability with Time-on-Stream of NaBr-Promoted KY Zeolite Catalyst for the Oxidative Methylation of Toluene with Methane

Zhou Ling-Ping;Li Wei;Tao Ke-Yi;Li He-Xuan;Li Xuan-Wen   

  1. College of Chemistry and Molecular Engineering, Peking University, Beijing　100871;College of Chemistry, Nankai University, Tianjin　300071
  • Received:2002-01-29 Revised:2002-04-24 Published:2002-10-15
  • Contact: Zhou Ling-Ping E-mail:zhou_ling_ping@hotmail.com

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摘要： 考察了NaBr/KY催化剂的甲苯氧化甲基化(OMT)反应的稳定性，经过50 h的OMT反应结果表明，在反应初期，甲苯转化率、总C8选择性均有不同程度的下降，之后趋于稳定.在总C8产物中，苯乙烯的选择性随着反应的进行呈下降趋势，而乙苯的选择性与苯乙烯相比呈相反的变化趋势.此外，利用XRD、骨架IR、XPS对反应前后的催化剂结构进行了研究，发现催化剂经过50 h的OMT反应，分子筛的结构遭到了部分破坏，但其基本骨架仍保留.

关键词: KY沸石, 甲苯, 甲烷, 氧化甲基化, 稳定性

Abstract: The stability with time-on-stream of NaBr-promoted KY zeolite catalyst for the oxidative methylation of toluene with methane has been investigated. The results showed that during 50 h of reaction, the toluene conversion and the total C8 selectivity decreased fast at the first and then basically remained unchanged, they kept at about 35％ and 65％－70％ respectively. The selectivity of styrene decreased while the selectivity of ethyl benzene increased during the reaction process. This result was ascribed to the estimation that the styrene was formed by the dehydrogenation of ethyl benzene and the dehydrogenation activity decreased in the reaction process. In addition, the structure of the catalyst used was also studied by XRD, IR and XPS. It was found that the zeolite catalyst suffered dealumination, elimination of KBr and partial destruction of structure but the zeolite framework still retained.

Key words: KY zeolite, Toluene, Methane, Oxidative methylation, Stability