杂多酸在活性炭上的固载化Ⅲ．活性炭在酸性介质中对钨硅杂多酸（SiW_（12））的吸附

在氢离子浓度均为３ｍｏｌ／Ｌ的硫酸，盐酸，磷酸，醋酸水溶液中和冰醋酸中研究了具有Ｋｅｇｇｉｎ结构的硅钨杂多酸（ＳｉＷ＿（１２））在不同来源活性炭上的吸附作用。各活性炭对ＳｉＷ＿（１２）吸附等温线的形式是不相同的，吸附剂载体的微孔结构以及杂多酸的溶剂化起着重要的作用。并且在无机酸介质中，杂多酸的吸附量比在水溶液中成规律性地增加，且与酸强度成正比关系。在有机酸介质中，吸附作用比较复杂。根据所得结果，提出了在酸性介质中杂多酸在活性炭表面的吸附模型。     

功能化MCM-41在有机合成中的应用

介孔分子筛MCM-41具有较高的比表面和规整的结构以及表面带有羟基,因此可对MCM-41进行官能团化,从而实现均相催化剂在MCM-41中的组装,达到均相催化剂多相化的目的。本文介绍了最近几年以MCM-41为主体,组装均相配合物得到固相化催化剂在氧化、还原、烷基化、氢甲酰化、Heck、环丙烷化等反应中的应用。     

催化膜和催化膜反应器:整合的高效和环保催化过程

 The design of new heterogeneous photooxygenation systems able to employ visible light, oxygen, mild temperatures, and solvent with a low environmental impact has been investigated. In particular, the heterogenization of decatungstate (W10O4-32), a polyoxometalate with photocatalytic activity in oxidation reactions, has been carried out in polymeric membranes of polyvinylidenefluoride. The polymeric catalytic membranes prepared by phase inversion technique have been successfully applied in the aerobic mineralization of phenol in water, which was used as an example of organic pollutant. In order to evaluate the effect of the polymeric environment on the overall catalyst behavior, we have also heterogenized the decatungstate (opportunely functionalized) in perfluorinated membrane made of Hyflon. The photocatalytic composite membranes are characterized by different and tuneable properties depending on the nature of the polymeric micro-environment, in which the catalyst is confined. Moreover, the selective separation function of the membrane results in enhanced performance in comparison with homogeneous reactions.     

多联吡啶钴分子催化剂异相化光催化还原二氧化碳研究进展

利用太阳能将二氧化碳还原为高附加值燃料是当前双碳背景下解决能源和环境问题的有效方案. 金属配合物分子催化剂作为一种均相催化剂, 具有明确的活性位点、高反应活性以及可调的化学结构等特点, 非常有利于提高催化性能和研究催化机理, 在二氧化碳还原反应中已得到广泛应用. 然而, 分子催化剂稳定性不高且难以回收利用, 不利于催化反应的工业化应用. 采用固定化策略构筑分子催化剂/载体的异相化体系在一定程度上解决了这一难题. 我们综述了以多联吡啶类有机物(主要为二联吡啶、三联吡啶、四联吡啶)为配体的钴分子催化剂, 通过共价键合、非共价键合以及构筑有序聚合物等途径异相化在光催化还原二氧化碳方面的研究进展, 最后对分子催化剂异相化的体系在该领域发展面临的挑战进行了总结.     

Silica–PSCl3: A Mild and Efficient Reagent for Deoxygenation of Sulfoxides

A new solid supported reagent, silica–PSCl₃, has been developed for deoxygenation of sulfoxides. With this reagent, conversion of sulfoxides to sulfides occurred cleanly and efficiently at room temperature. Facile isolation of the product was achieved by simple filtration of the by‐products without any extensive workup.     

Pentamethylcyclopentadienylrhodium(I) complexes incorporated into porous polysiloxanes prepared by a sol–gel process: catalysts for hydrogenation of crotonic acid in water

Pentamethylcyclopentadiene‐functionalized polysiloxanes were prepared by a sol–gel process from tetraethoxysilane and (pentamethylcyclopentadienylmethyl)methyldiethoxysilane without a catalyst. The polysiloxanes are microporous–mesoporous solids, of which the BET surface areas and micropore volumes are inversely proportional to the concentration of the functionalizing agent (5–21 mol%) in the starting mixture of alkoxysilanes. The polysiloxanes were also characterized by CP MAS ¹³C NMR spectroscopy, revealing essentially the same structure of organofunctional ligand as that in particulate materials with low surface areas prepared earlier in a sol–gel process catalyzed by dibutyltin diacetate. Novel alkoxysilyl‐substituted pentamethylcyclopentadienyl (1,5‐cyclo‐octadiene)rhodium(I) complexes were synthesized from the corresponding cyclopentadienes by deprotonation followed by reaction with [(cod)RhCl]₂ (cod = cyclo‐octadiene). Polysiloxane‐bound rhodium complexes were prepared by a sol–gel reaction analogous to the one mentioned above and were found to catalyze the hydrogenation of crotonic acid in water; to the best of our knowledge, this constitutes the first example of catalysis by a well‐defined polysiloxane‐bound transition metal complex in an aqueous system. Copyright © 2000 John Wiley & Sons, Ltd.