阳离子掺杂水滑石的制备及其性质研究

研究了掺杂阳离子水滑石的制备及阳离子对水滑石性质的影响. 分别制备了掺杂Zn2+、Ni2+、Fe3+型的水滑石, 考察了掺杂阳离子对水滑石晶相结构、层间距、层间阴离子含量、水滑石表面形态、水滑石碱性的影响, 结果表明, 由于阳离子的引入, 导致水滑石层间距减小及层间阴离子结合量降低, 且使水滑石培烧产物电负性提高, 并最终降低其碱性. 以上述水滑石培烧产物作为固体碱催化剂促进苯甲醛和丙醛缩合, 合成α-甲基肉桂醛, 关联了水滑石培烧产物碱性与反应活性的关系.

Studies of the Mg-Al and Cation-Incorporated Hydrotalcites

Mg-Al and cation-incorporated(containing Zn2+、Ni2+、Fe3+) hydrotalcites were synthesized and characterized. A detailed comparative analysis of structure and composition was made. Different cations influenced strongly textural parameters of hydrotalcites and the basicity of the obtained Mg-Al oxides after calcinations. With the cation incorporation, the distance of the brucite and the mount of CO32－as the compensating anion changed. Meanwhile the CO2-TPD was used to determine the basicity of the samples. The results showed that the basicity of the calcined hydrotalcites reduced. Finally, the activated hydrotalcite catalysts may efficiently replace homogeneous catalysts in Claisen-Schmidt condensation reaction of the benzaldehyde and propanal. And it was noteworthy that the calcined cation-type(containing Zn2+、Fe3+) hydrotalcites as catalysts did not show significant activity, in agreement with their low basicity.