微量吸附量热法研究Zn-Al水滑石及其衍生复合氧化物的酸碱性质  

MICROCALORIMETRIC STUDIES OF SURFACE ACIDITY AND BASICITY OF ZnAl HYDROTALCITES AND THEIR DECOMPOSITIONS

作　　者：李大塘[1,2,3] 杨丽筠 屠迈 沈俭一[1,2,3] 

机构地区：[1]南京大学化学化工学院 [2]湘潭师范学院化学系 [3]江苏广播电视大学

出　　处：《南京大学学报（自然科学版）》1998年第1期114-118,共5页Journal of Nanjing University（Natural Science）

基　　金：国家教委跨世纪优秀人才基金;国家自然科学基金

摘　　要：由共沉淀法合成了Ｚｎ／Ａｌ摩尔比为１、２、３和６的Ｚｎ－Ａｌ水滑石．热重－差热结果显示其分解经两个过程，分别对应１８０和２２０℃的吸热峰．经４００℃焙烧，生成Ｚｎ－Ａｌ复合氧化物，ＸＲＤ测定仅显示ＺｎＯ物相（除Ｚｎ／Ａｌ比为６的样品），表明组成成分均一．微量吸附量热结果表明Ｚｎ－Ａｌ复合氧化物的表面酸碱性介于γ－Ａｌ２Ｏ３和ＺｎＯ之间，碱性（酸性）随着Ｚｎ（Ａｌ）含量的增加而增强．A series of ZnAl hydrotalcites with Zn/Al molar ratios of 1,2,3, and 6 was prepared by the coprecipitation method. Results of TGDTA showed that they decomposed in two stages, corresponding to the endothermic peaks at 180℃ and 220℃, respectively. After calcination at 400℃, the hydrotalcites were converted into ZnAl mixed oxides, showing only the XRD patterns of ZnO except for the one with the ratio of 6. Microcalorimetric studies indicated that the acidity and basicity of the mixed oxides were between those of ZnO and Al2O3. The increase of the Zn/Al ratios enhanced the surface basicity while reduced the surface acidity of the mixed oxides.

关 键 词：微量吸附量热 水滑石 复合氧化物 锌 铝 催化剂 

分 类 号：O643.36[理学—物理化学]