能源化学(英文版)

能源化学(英文) ›› 2003, Vol. 12 ›› Issue (4): 259-263.

• Articles • 上一篇    下一篇

Preparation, Characterization and Application of ZnAlLa-Hydrotalcite- Like Compounds

Xianmei Xie, Xia An, Xiulan Wang, Zhizhong Wang   

  1. College of Chemical Engineering and Technology, Taiyuan University of Technology, Taiyuan 030024, China
  • 出版日期:2003-12-30 发布日期:2003-12-30

Preparation, Characterization and Application of ZnAlLa-Hydrotalcite- Like Compounds

Xianmei Xie, Xia An, Xiulan Wang, Zhizhong Wang   

  • Online:2003-12-30 Published:2003-12-30

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摘要： The preparation of ZnAlLa-hydrotalcite-like compounds [ZnAlLa-HTLcs] was studied. ZnAlLa-HTLcs were synthesized by a method of variable pH with the raw materials of Zn(NO3)2, Al(NO3)3, La(NO3)3, and NaOH. The e ects of some factors (i.e. pH values, the mole ratio of Al3+ to La3+, temperature and the period of hydrothermal treatment) on the preparation of HTLcs were discussed systematically. XRD, TG-DTA, FT-IR spectroscopy, and ICP were performed to characterize ZnAlLa-HTLcs samples, and the thermal stability of HTLcs was also discussed. It was shown that unique ZnAlLa-HTLcs with high crystallinity can be prepared, under the conditions of pH=5.5-6.5, n(Zn2+)/n(Al3++La3+)=2 and the atomic ratio of La3+ to Al3+ ranging from 0.07 to 2, hydrothermal treatment at 120oC for 5 h. When the calcination of the HTLcs is performed at temperatures above 200oC , ZnO phase is detected with Al2O3 and La2O3 spreading on its top. The complex metal oxides derived from ZnAlLa-HTLcs at 500oC have higher catalytic activity and selectivity than those from ZnAl-HTLcs for the esterification of acetic acid with n-butanol under the same reaction conditions.

关键词: layered compound, double hydroxide, anionic clay, hydrotalcite, ZnAlLa, preparation, characterization, application

Abstract: The preparation of ZnAlLa-hydrotalcite-like compounds [ZnAlLa-HTLcs] was studied. ZnAlLa-HTLcs were synthesized by a method of variable pH with the raw materials of Zn(NO3)2, Al(NO3)3, La(NO3)3, and NaOH. The e ects of some factors (i.e. pH values, the mole ratio of Al3+ to La3+, temperature and the period of hydrothermal treatment) on the preparation of HTLcs were discussed systematically. XRD, TG-DTA, FT-IR spectroscopy, and ICP were performed to characterize ZnAlLa-HTLcs samples, and the thermal stability of HTLcs was also discussed. It was shown that unique ZnAlLa-HTLcs with high crystallinity can be prepared, under the conditions of pH=5.5-6.5, n(Zn2+)/n(Al3++La3+)=2 and the atomic ratio of La3+ to Al3+ ranging from 0.07 to 2, hydrothermal treatment at 120oC for 5 h. When the calcination of the HTLcs is performed at temperatures above 200oC , ZnO phase is detected with Al2O3 and La2O3 spreading on its top. The complex metal oxides derived from ZnAlLa-HTLcs at 500oC have higher catalytic activity and selectivity than those from ZnAl-HTLcs for the esterification of acetic acid with n-butanol under the same reaction conditions.

Key words: layered compound, double hydroxide, anionic clay, hydrotalcite, ZnAlLa, preparation, characterization, application