Dissolution of oxide supports during the preparation of supported catalysts, a case study: Silica

COLL 175

Catherine Louis, Laboratoire de Réactivité de Surface, UMR 7609-CNRS, Laboratoire de Réactivité de Surface, UMR 7609-CNRS, Université Pierre et Marie Curie, 4 Place Jussieu, 75252 Paris Cedex 05, France
This presentation aims at showing that silica used as catalyst support, may not only play the role of support, but can react with metal complexes to form silicates: - in solution during catalyst preparation, i.e., at the solid-liquid interface, through a mechanism of silica dissolution and reprecipitation as a silicate. Examples of several systems, Ni/SiO2, Cu/SiO2, Co/SiO2 prepared by the procedure of cation adsorption, will be presented. The parameters responsible for this phenomenon will be identified; - during thermal treatments, even at moderate temperature, after deposition of the precursors on the silica support. The case of Zn/SiO2 will be addressed.