高温水热对Mg_3Al-CO_3^(2-)水滑石结晶过程的影响研究  

Effect of Hydrothermal Conditions on the Crystallization of Mg_3Al-CO_3^(2-)Hydrotalcite

作　　者：苏继新[1] 王晓鹏[1] 潘齐[1] 屈文[1] 

机构地区：[1]山东大学环境科学与工程学院,济南250100

出　　处：《无机化学学报》2007年第6期1015-1020,共6页Chinese Journal of Inorganic Chemistry

基　　金：山东省优秀中青年科学家科研奖励基金(No.2004BS08010)资助项目。

摘　　要：采用XRD、TEM、TG-DTA、TPD等表征手段研究了高温水热处理过程对镁铝碳酸根水滑石结晶度、晶面衍射相对强度、层间CO32-阴离子的性质以及高温水热处理恢复得到的镁铝水滑石的晶态结构等性质的影响。结果表明:水热温度低于270℃,随温度升高,样品结晶度增加,(003)、(006)晶面优势生长。HT样品的分解随水热温度的增加,脱碳酸根过程向高温区偏移,并且分解温度区间渐窄。水热有利于LDO(layereddoubleoxides)样品的恢复,热分解产生的MgO、AlO(OH)、MgAl2O4尖晶石相恢复进入水滑石层间结构的顺序为MgO>AlO(OH)>MgAl2O4。The effect of hydrothermal treatment conditions on Mg-A1 hydrotalcite carbonate crystallization, the relative crystal diffraction intensity, CO3^2-interlayer anion state and the layered double oxides （LDO） reconstruction was studied by XRD, TEM, TG-DTA and temperature program decomposition （TPD）. The results showed that the crystallinity of samples increased with hydrothermal temperature and （003）, （006） faces grew preferentially when the hydrothemal temperature was lower than 270 ℃. The crystallinity of hydrotalcites destroyed when the temperature was higher than 270 ℃. The decomposition temperature of the hydrotalcite （HT） to LDO was between 300 ℃ and 380 ℃. The decarbonization process of HT samples treated with higher hydrothermal temperature moved to higher temperature region and the decomposition temperature interval was narrowed down. LDO was easy to reconstruct to hydrotalcite at hydrothermal conditions. MgO in LDO was easier to recover into HT than AlO（OH） and MgAl2O4.

关 键 词：高温水热 水滑石 结晶 

分 类 号：O614.22[理学—无机化学] O741.3[理学—化学]