稀土类水滑石的制备及其催化性能的研究

摘要

Zn-Al Hydrotalcite-like( ZnAl-HTLcs)and Zn-Al-Ce hydrotalcite-like( ZnAlCe-HTLcs)were synthesized by co-precipitation and hydrothermal synthesis methods,and measured by XRD. The results show that:under the M2+:M3+ =2,Ce3+:Al3+ =0. 25,pH = 5. 8 ~6. 5 ,a single synthetic ZnAl-HTLcs and ZnAlCe-HTLcs can be obtained. As a precursor after the calcination temperature by a certain complex metal oxide catalysts have been studied in the acetic acid catalyst for esterification of N-pentanol in the application of the detailed effects of catalyst composition and reaction conditions on catalytic activi-ty. When molar ratio of M2+:M3+ is 2 and molar ratio of Ce3+:Al3+ is 0. 25,catalyst at 500 ℃ calcina-tion have a better catalytic activity in acetic acid up to a maximum conversion rate of 78 . 7%.%采用共沉淀水热合成锌铝类水滑石（ ZnAl-HTLcs）和锌铝铈三元类水滑石（ ZnAlCe-HTLcs）。并利用XRD对不同条件下合成产物进行物相分析。实验结果表明，在M2+：M3+=2，Ce3+：Al3+=0.25，pH=5.8~6.5下，进行多种离子共沉淀，均能合成结构单一的ZnAl-HTLcs 和 ZnAlCe-HTLcs。并以此为前驱体经一定温度焙烧后得到复合金属氧化物催化剂，研究了催化剂在乙酸戊醇酯化反应中的应用。当M2+：M3+为2，Ce3+：Al3+为0.25条件下，催化剂在实验条件下均具有较好的催化活性，其中经500℃下焙烧的催化剂，乙酸的转化率最高可达78.7%。