Controlled synthesis of porous heteropolysalts used as catalysts supports

Abstract

Abstract The preparation conditions of heteropolycompounds (HPC) dramatically influence the morphology of the crystals and therefore the heteropolysalts textural properties. When HPC are used as supports it is likely to have a strong influence on the catalytic performances. In this work we try to clarify this point using a perfectly stirred instrumented semi-batch reactor in order to prepare a series of Cs3PMo12O40 Keggin heteropolysalts. Preparation conditions (namely reactants concentrations, reaction and maturation temperature, addition rate and maturation time) have been varied following an experimental design (Hadamard matrix). The aim was to rule out the influence of the preparation conditions on the textural properties of the HPC, which were determined by nitrogen adsorption using the BET and BJH methods. The results show the excellent reproducibility of the supports preparation procedure, as well as the strong effect of the preparation conditions on the textural properties of HPC.