中华医学超声杂志

应用化学 ›› 1989, Vol. 0 ›› Issue (4): 18-21.

• 研究论文 • 上一篇    下一篇

稀土改性MoO3/SiO2催化剂上丙烯的歧化

张报安, 孙彦妮, 金玳, 林青松, 吕连海   

  1. 大连理工大学, 化学系
  • 收稿日期:1988-04-26 修回日期:1988-10-14 出版日期:1989-08-10 发布日期:1989-08-10
  • 基金资助:
    国家教委科学基金

STUDY OF PROPENE METATHESIS ON MoO3/SiO2 CATALYST PROMOTED BY RARE EARTH OXIDES

Zhang Baoan, Sun Yanni, Jin Dai, Lin Qingsong, Lu Lianhai   

  1. Department of Chemistry, Dalian University of Technology
  • Received:1988-04-26 Revised:1988-10-14 Published:1989-08-10 Online:1989-08-10

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摘要： 本文系统考察了镧系14种稀土氧化物对烯烃歧化催化剂MoO3/SiO2的影响,发现其中多数均可使催化剂的寿命延长,并以Tb及Pr的效果最佳,其稳定时间可达未改性时的1.6倍。主要原因是稀土添加剂有抑制积炭的能力和缩短催化剂的增活期(为未改性的40%～75%)。通过ESR表征,从本质上阐明了Tb4O7的作用在于促进了歧化活性中心——挠动四棱锥结构的Mo5+值的增长。在增活期过程中,活性物种前体的减少服从一级反应力学规律。

关键词: 稀土氧化物, 歧化反应, 三氧化钼催化剂

Abstract: The metathesis of propene has been carried out on the MoO3/SiO2 catalyst modifiedwith rare earth oxides. In is found that most of the Ln2O3 can prolong the life of thecatalysts and shorten the "break-in" period. Among them Tb4O7 and Pr6O11 exhibiteda more marked effect. The stable duration of catalyst modified by Tb4O7 can be prolongedto approximately 1.6 times as long as that of the unmodified one. The "break-in" periodwas reduced to about 40% to 75%. From the results of the Tb4O7. MoO3/SiO2 catalyst, itcan be concluded that the role of Tb4O7 is in facilitating the formation of the activesurface site, i.e. the distorted square pyramidal Mo5+. The reaction of active sitc formationis in first order with respect to the precurser of the active species.

Key words: Rare earth oxides, Metathesis, MoO3 catalyst

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