Catalyst supports anionic minerals

Over the past 15-20 years, there has been a renewed and growing interest in the use of clay minerals as catalysts or catalyst supports. Most of this interest has focused on the pillaring of smectite clays, such as montmorillonite, with various types of cations, such as hydrated metal cations, alkylammonium cations and polycations, and polynuclear hydroxy metal cations (1-17). By changing the size of the cation used to separate the anionic sheets in the clay structure, molecular sieve-like materials can be made with pore sizes much larger than those of conventional zeolites. 

In literature, a succesfull attempt has been reported, where Ru(II)-BINAP is sulfonated and immobilized by the supported aqueous phase technique [3]. We successfully immobilized this type of complexes in two different ways In a first system, we incorporated the Ru(II)-BINAP in a polydimethylsiloxane (PDMS) matrix [4]. In this paper, a second way of immobilizing the Ru(II)-BINAP catalyst, by ion exchange of the sulfonated complex on anionic minerals, is described. 

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