杂多酸的固载化─关于制备负载型酸催化剂的一般原理

杂多酸同时具有酸和氧化－还原的催化特性，有着很广泛的应用前景．这类化合物在一系列精细合成中取代硫酸作为催化剂以满足环保的要求，显示出了很大的潜力．杂多酸固载化后，不仅能在液相氧化和酸催化反应中把催化剂从反应介质中很方便地分离出来，而且还为这类均相催化反应的多相化，甚至利用催化蒸馏新工艺等创造了应有的条件，可以使生产工艺大大简化，获得更广泛的应用．本文以很好表征过的多种孔性材料，包括氧化物，如Ａｌ_２Ｏ_３、ＳｉＯ_２、ＴｉＯ_２、硅藻土、膨润土和来源不同的活性炭为载体，考察了负载杂多酸催化剂的催化活性．在大量前期工作的基础上，通过总结载体对固载杂多酸催化活性的影响等，探讨载体的内在性质在杂多酸固载、吸附和催化反应中的作用本质，为由吸附法制备各种负载型固体酸催化剂在液相中的应用提供可资参考的模型．

Heterogenization of Heteropolyacids A General Discussion on the Preparation of Supported Acid Catalysts

Heteropolyacids (HPAs) possess both acidic and redox catalytic properties and own extensive promise of practical application. This type of compounds displays a great potential in a series of special synthesis reactions for replacing sulfuric acid to satisfy the requirements of environmertal protection. Heterogenizing HPAs would not only make them more useful in liquid phase oxidation with oxygen and in acid-catalyzed reaction, in which the catalyst is often difficult to be separated from the reaction products, but also create favourable factors for realizing heterogenization of homogeneous reaction and even utilizing the new technology of catalytic distillation. In this paper, different kinds of well characterized porous materials including oxides such as Al2O3. SiO2. TiO2 diatomite, beutonite and activated carbons of different source were used as supports for heterogenizing HPAs in different mediums, and the catalytic activity of supported HPA was investigated. Base on the results obtained the intrinsic character of supports which influence the nature of the interaction between HPAs and supports in heterogenization and the catalytic activity in the catalytic reaction has been explored. It is expected that these results could provide a referential model for preparing supported acid catalyst used in liquid phase.