Hybrid Organic-Inorganic Materials: Application in Oxidative Catalysis pp. 161-186
Authors: (Graša M.S.R.O. Rocha, Department of Chemistry, Campus de Santiago, University of Aveiro, Aveiro, Portugal)
Abstract: Oxidative catalysis has been and will be playing an important role in the production of large quantities of intermediates. This technology has a great potential for improvement and this has led to a series of better processes, including the development of a great diversity of suitable catalysts. Within these compounds, metal phosphates and phosphonates possessing layered and pillared structures were found to constitute a very good alternative as catalysts to be used in oxidative catalysis. Metal phosphates and phosphonates can be considered as strong inorganic solid acids and much of their catalytic activity has been attributed to the Br°nsted acidity of the interlayered hydroxyl groups and to the Lewis acidity of the metal center. Metal phosphates and phosphonates can be obtained at low temperatures, in aqueous media, using soft chemical routes and their preparation is quite accessible if the correct phosphonic acids and phophates are available. These heterogeneous materials are very interesting from the economical as well as from the environmental points of view because of the high yields and short reaction times, easy recovery from the reaction mixtures and the possibility to perform reactions in solvent-free conditions.