Acta Chimica Sinica ›› 1995, Vol. 53 ›› Issue (6): 603-609. Previous Articles     Next Articles

Original Articles

铁-锆交联蒙脱土的制备和结构表征

沫来龙;颜其洁;陈立刚;金永漱   

  1. 南京大学化学系;南京大学现代分析中心
  • 发布日期:1995-06-15

Preparation and characterization of hydroxy-Fe-Zr pillared crossed-linked montmorillonites

MO LAILONG;YAN QIJIE;CHEN LIGANG;JIN YONGSHU   

  • Published:1995-06-15

Hydroxy-Fe-Zr pillared clays (Fe-Zr-PILC) with basal spacing of 1.84nm was first prepared. Three different preparation routes were studied. The most stable Fe-Zr-PILC can be obtained by first intercalating montmorillonite with hydroxy-Zr to prepare Zr-PILC and then using hydroxy-Fe-pillaring agent to intercalating Zr-PILC. For comparison study, Fe-PILC and Zr-PILC were also prepared. The pillar structure, and thermal stability of the samples were determined by XRD, BET surface area and average pore diameter measurement and Mossbauer spectroscopy. It was found that the surface area of the prepared Fe-Zr-PILC was 158m^2/g almost three times larger than that of the montmorillonite. after treated in air at 500℃, for this sample the basal spacing was kept almost unchanged, but the surface area decreased to 98.8m^2/g. For Fe-PILC, after treated at 350℃, due to the collapse of the Fe pillar, the basal spacing decreased from 1.64nm to 1.04nm and the surface area decreased from 143.8m^2/g to 114.6m^2/g. However after treated at 500℃ in air, the basal spacing and the surface area of Zr-PILC were all kept constant. So we may suggest that the Zr-pillar is responsible for the constant basal spacing of Fe-Zr-PILC and the decrease of the surface area and the increase of the average pore diameter in due to the callapse of the Fe pillar. Mossbauer study showed that after treated at 500℃, for Fe-PILC, α-Fe~2O~3 was formed, but only Fe^2^+ and supermagnetic Fe^3^+ species can be found for Fe-Zr-PILC, It seems that there is a strong interaction between iron and zirconium component in Fe-Zr-PILC, the iron oxide component in Fe-Zr-PILR is highly dispersed on Zr pillar surface as supermagnetic state and in this case, the crystalline α-Fe2O3, can not be formed. After reduced in H2 at 400℃, 64% iron oxide pillar in Fe-PILC was reduced to Fe°, however, in Fe-Zr-PILC, due to the Fe-Zr interaction, iron component still kept as Fe^3^+ and Fe^2^+ state even after reduction at 450℃.

Key words: PREPARATION, IRON, ZIRCONIUM, STRUCTURE

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