高等学校化学学报 ›› 1994, Vol. 15 ›› Issue (11): 1670.

• 论文 • 上一篇    下一篇

ZSM-5沸石中V的还原性能

张春雷, 吴志芸   

  1. 吉林大学化学系, 长春, 130023
  • 收稿日期:1993-11-06 修回日期:1994-03-10 出版日期:1994-11-24 发布日期:1994-11-24
  • 通讯作者: 张春雷,男,25岁,博士研究生.
  • 作者简介:张春雷,男,25岁,博士研究生.
  • 基金资助:

    国家自然科学基金

Reducibility of Vanadium in Zeolite ZSM-5

ZHANG Chun-Lei, WU Zhi-Yun   

  1. Department of Chemistry, Jilin University, Changchun, 130023
  • Received:1993-11-06 Revised:1994-03-10 Online:1994-11-24 Published:1994-11-24

摘要: 用TPR并结合XRD、ESR和XPS等测试手段研究了V(Ⅳ,Ⅴ)-ZSM-5、V2O5-/ZSM-5(分别用浸渍法和机械混合法制备)及V2O5样品的还原性能,获得了还原过程中物相及钒离子价态变化的信息,发现分散在分子筛表面上的V(Ⅴ)还原温度比V2O5低,而位于ZSM-5骨架上的V(Ⅴ)却比V2O5更难还原。高于1200K骨架V才开始还原;高于1370K,V-ZSM-5分子筛开始解体并转变成方英石结构,从骨架中析出的V完全还原成低价态。

关键词: V-ZSM-5, TPR, ESR, 钒价态

Abstract: The reducibility of V(Ⅳ, )-ZSM-5 and V2O5/ZSM-5(preapred by impregnation (Method I) and mechanical mixing(Method Ⅱ), respectivitly) was studied by TPR, XRD, ESRand XPStechniques, Some singificant information about phase changes during the reduction was obtained. It was found that the reduction temperature of V(v)dispersed on the surface of zeolite was lower than that of V2O5. However, V(v)in the lattice of ZSM-5 was more difficult to be reduced; Its reduction temperature is over l200 K. When the temperature was raised to or over 1370 K, V-ZSM-5 was converted into christobalite-structured phase, In this state, V(v)separated form the frameworks was completely reduced to the lower valence.

Key words: V-ZSM-5, TPR, ESR, Valence state of vanadium

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