物理化学学报 >> 1994, Vol. 10 >> Issue (11): 992-997.doi: 10.3866/PKU.WHXB19941106

研究论文 上一篇    下一篇

镍盐和氧化镍在NaY沸石中存在状态研究

高滋, 崔峻   

  1. 复旦大学化学系,上海 200433
  • 收稿日期:1993-09-20 修回日期:1994-03-11 发布日期:1994-11-15
  • 通讯作者: 高滋

Studies on the Dispersion States of Nickel Salt and Oxide on NaY Zeolites

Gao Zi, Cui Jun   

  1. Department of Chemistry,Fudan University,Shanghai 200433
  • Received:1993-09-20 Revised:1994-03-11 Published:1994-11-15
  • Contact: Gao Zi

摘要:

用XRD、EXAFS和TPR方法研究了Ni(NO3)2/NaY和NiO/NaY分散体系. 在沸石上,Ni(NO3)2的分散比NiO容易得多XRD相定量方法测定的NiO在NaY沸石上的分散阈值很低,仅为密置单层容量的2%左右.在分散阈值前NiO在沸石上处于分散相和笼外小晶粒两种状态.分散相NiO比笼外NiO小晶粒难还原.样品中NiO含量超过阈值时,笼外小晶粒长大成XRD可检测的较大晶粒.

关键词: Ni(NO3)2/NaY, NiO/NaY, 分散状态, EXAFS, TPR

Abstract:

The Ni(NO3)2/NaY and NiO/NaY dispersed systems were studied by XRD,EXAFS, and TPR methods. It has been found that Ni(NO3)2 is more readily dispersed on NaY than NiO. The dispersion threshold of NiO on NaY has been determined by XRD quanitative phase analysis, and it amounts only to 2% of the close packed monolayer capacity. Before the dispersion threshold NiO on the zeolite exists as the dispersed NiO phase and small NiO crystallites outside the zeolite cage. The dispersed NiO phase is more difficult to reduce than the small NiO crystallites. As the NiO content in the sample is increased above the dispersion threshold, the small NiO crystallites outside the zeolite cage grow into larger crystallites detectable by XRD.

Key words: Ni(NO3)2/NaY, NiO/NaY, Dispersion threshold, Dispersion state, EXAFS, TPR