Thermal decomposition of the synthetic hydrotalcite woodallite

被引：19

作者：

Bouzaid, J. M. ^{[1
]}

Frost, R. L. ^{[1
]}

Musumeci, A. W. ^{[1
]}

Martens, W. N. ^{[1
]}

机构：

[1] Queensland Univ Technol, Sch Phys & Chem Sci, Inorgan Mat Res Program, Brisbane, Qld 4001, Australia

来源：

JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY | 2006年 / 86卷 / 03期

关键词：

dehydration; dehydroxylation; high-resolution thermogravimetry; hydrotalcite; iowaite; woodallite;

D O I：

10.1007/s10973-005-7315-2

中图分类号：

O414.1 [热力学];

学科分类号：

摘要：

The thermal stability and thermal decomposition pathways for synthetic woodallite have been determined using thermogravimetry in conjunction with evolved gas mass spectrometry. Chemical analysis showed the formula of the synthesised woodallite to be Mg6.28Cr1.72Cl(OH)(16)(CO3)(0.36)center dot 8.3H(2)O and X-ray diffraction confirms the layered LDH structure. Dehydration of the woodallite occurred at 65 degrees C. Dehydroxylation occurred at 302 and 338 degrees C. Both steps were associated with the loss of carbonate. Hydrogen chloride gas was evolved over a wide temperature range centred on 507 degrees C. The products of the thermal decomposition were MgO and a spinel MgCr2O4. Experimentally it was found to be difficult to eliminate CO2 from inclusion in the interlayer during the synthesis of the woodallite compound and in this way the synthesised woodallite resembled the natural mineral.

引用

页码：745 / 749

页数：5

共 23 条

[1] Cu/Ni/Al layered double hydroxides as precursors of catalysts for the wet air oxidation of phenol aqueous solutions [J].