**2.1. Preparation of composite supports**

A brief summary is presented about the preparation and use of different organic-inorganic supports and catalysts. The materials are divided into three classes and each one is studied separately:


The different strategies of synthesis of these metal/polymer catalysts are shown in **Figure 1**.

For the preparation of these catalysts, the organic support is commonly prepared from acrylic or vinylic monomers. Polymerization cross-linking is adjusted by the use of additives, with a minimum value for preventing the dissolution in the solvents used in the subsequent reactions. Metals with catalytic properties are placed over these supports. Oxidized metal precursors are reduced to the metal state with the help of reducing chemical agents in solution or by the use of molecular hydrogen. For these kind of supports styrene and divinylbenzene N,N-dimethylacrylamide, 2-acrylamido-2-methylpropane sulfonic acid, methacrylic acid , 4-vinylpyridine, glycidyl methacrylate ethylene glycol dimethacrylate, etc. are the monomers of choice.

New Strategies for Obtaining Inorganic-Organic Composite Catalysts for Selective Hydrogenation http://dx.doi.org/10.5772/65959 185
