物理化学学报 >> 1986, Vol. 2 >> Issue (01): 51-58.doi: 10.3866/PKU.WHXB19860108

研究论文 上一篇    下一篇

低镍甲烷化催化剂中镍和氧化镧的分散研究

沈岳年; 郭清松; 张立; 锡林   

  1. 内蒙古大学, 呼和浩特; 内蒙古科委测试中心, 呼和浩特
  • 收稿日期:1984-12-25 修回日期:1985-10-14 发布日期:1986-02-15

DISPERSION OF NICKEL AND La2O3 IN LOW-CONTAINING Ni-CATALYST OF METHANATION

Shen Yuenian; Guo Qingsong; Zhang Li; Xi Lin   

  1. Department of Chemistry, Inner Mongolia University, Huhehaote; Service Centre of test, Science Committee of Inner Mongolia, Huhehaote
  • Received:1984-12-25 Revised:1985-10-14 Published:1986-02-15

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摘要： 本文用X射线衍射法(XRD), 透射电镜(TEM), 配合电子衍射对Ni/Al2O3,Ni/γ-Al_2O_3-La_2O_3等催化剂中镍晶粒度和La_2O_3的分散状态进行了测量和讨论。用透射电镜测量了不同La_2O_3含量的催化剂中镍晶粒度分布, 其平均直径可与X射线宽化法测定值相比较。催化剂中随La_2O_3加入量的增加, Ni晶粒有细化趋势, 从而提高了甲烷化催化活性。对La_2O_3在γ-Al_2O_3表面作密置单层分散的模型提出了新的旁证, 并推断由于La_2O_3在γ-Al_2O_3表面高分散并产生较强相互作用, 使γ-Al_2O_3接近表层晶格发生畸变。

Abstract: Ni/γ-Al_2O_3, Ni/γ-Al_2O_3-La_2O_3 (La_2O_3 6.7%)and Ni/γ-Al_2O_3-La_2O_3 (La_2O_3 11.7%) catalysts were prepared by incipient wetness technique. The particle size distribution (Fig.9) and the average size of nickel in these catalysts were determined by Transmission Electron Microscopy (TEM). Average particle size could be compared with the data determined by X-Ray Diffraction (XRD)(see Table 3). It has been found that the particle size of nickel in catalysts is decreasing (Table 1) and activity of methanation is increasing (Fig.2) as adding La_2O_3 to Nicatalyst. Results of TEM and XRD in this paper support the model suggested by Xie Youchang et. al., of close-packed monolayer La_2O_3 dispersed on γ-Al_2O_3 surface, if the amount of La_2O_3 is less than the threshold value (0.28 La_2O_3/100 m~2 γ-Al_2O_3). X-Ray line broaden of γ-Al_2O_3 lattice, due to La_2O_3 highly dispersed on the surface of alumina.