New Molecular Simulation Method To Determine Both Aluminum and Cation Location in Cationic Zeolites

The knowledge of aluminum distribution in zeolites is a difficult task due to limitations in experimental measurements. In the present paper, we propose a new methodology to simultaneously determined aluminum atoms distribution as well as the extraframework cation location in a given experimental structure of the framework and thus allows comparison of different synthesis routes. Aluminum mean distribution is obtained over a great number of configurations that are generated during the course of the simulations at finite temperature. The obtained aluminum atom repartition is in agreement with the experimental and model data available. The consequences of aluminum distribution on solid properties such as extraframework Na+ cation location have been analyzed and successfully compared with the available information for different zeolite topologies. The proposed methodology can be used as a powerful complementary tool for aluminum location on X-Ray or neutron experimental structure determinations.