A new synthesis method for the preparation of ITQ-7 zeolites and the characterisation of the resulting materials

A new and convenient synthesis procedure for the preparation of ITQ-7 within a wide range of compositions is described. The most relevant feature of this new method is that it has allowed to obtain the pure silica ITQ-7 zeolite that was not possible to synthesise since the earliest structure directing agent (SDA) reported for the synthesis of this material [L.A. Villaescusa, P.A. Barrett, M.A. Camblor, Angew. Chem. Int. Ed. 38 (1999) 1997] was discontinued from the commercial suppliers. The new SDA is N-butyl-N-cyclohexyl-pyrrolidinium cation that can be easily prepared through a reductive amination of ketones reaction followed by quaternisation of the resulting amines. This new SDA has allowed to synthesise ITQ-7 zeolites, as pure silica materials, but also Al has been introduced in its framework, providing acid properties to the resulting solids. In this work, the synthesis procedure and characterisation of the resulting solids will be presented in detail and compared to the ITQ-7 zeolites obtained through synthesis procedures previously reported [L.A. Villaescusa, P.A. Barrett, M.A. Camblor, Angew. Chem. Int. Ed. Engl. 38 (1999) 1997; A. Cantfn, A. Corma, M.J. Diaz-Cabanas, F. Rey, G. Sastre, Conf. Proc. 14th Int. Zeolite Conf., Cape Town, South Africa, 2004]. (c) 2005 Academie des sciences. Published by Elsevier SAS. All rights reserved.