化学学报 ›› 1988, Vol. 46 ›› Issue (2): 179-183. 上一篇    下一篇

研究论文

含稀土氨合成催化剂还原的研究

王文祥;孙淑君   

  1. 郑州大学化学系
  • 发布日期:1988-02-15

Studies on the reduction behavior of amonia synthesis catalysts containing rare earth oxides

WANG WENXIANG;SUN SHUJUN   

  • Published:1988-02-15

氨合成铁催化剂中添加稀土氧化物已有不少报道,有的活性有所提高.我们通过添加稀土. 调整催化剂组成和改进制工艺得到几种活性较高,而且是非常容易还原的催化剂.本文的目的是研究稀土氧化物对催化剂还原性能的影响及几种活性较高容易还原的含稀土催化剂的本征还原动力学.

关键词: 金属氧化物催化剂, 还原, 氧化物, 稀土化合物, 合成气合成氨

A TG-DTA thermal analyzer was used to study the reduction characteristics and kinetics of spherical molten Fe catalysts promoted with Al2O3, K2O, CaO, and some rare earth oxides. If the other constituents are unchanged, the rate of reduction decreases as the ionic radii of the added rare earth ions decrease. For the same kinds of rare earth oxides, the rates of reduction decrease as the amts. of added trivalent rare earth oxides increase. The reduction kinetics of several highly active reduction catalysts containing rare earth oxides were studied. The core and shell model may be applied. If q is the degree of reduction at time t for an isothermal catalyst reduction, a plot of 1-(1-q)1/3 vs. t gives a broken line. The activation energies can be calculated for different stages of reduction Both the step temperature programed reduction and the intrinsic kinetics of isothermal reduction show that it is possible to develop improved catalysts containing rare earth oxides with better reducibility than the current industrial spherical catalyst A110-5Q.

Key words: METALLIC OXIDE CATALYST, REDUCTION, OXIDE, RARE EARTH COMPOUNDS, AMMONIA SYNTHESIS

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