Zeolite compositions and preparation and use thereof

摘要

This invention relates to novel compositions of zeolites or microporous metallosilicatescharacterised by a continuous spatial distribution of the metal and silicon in the crystals and characterised by a crystal surface enriched in silicon relative to the internal part of the same crystals. This invention also relates to a synthesis method of producing these metallosilicates with spatial distribution of the constituting elements. These novel zeolitic compositions can be used in various hydrocarbon conversion reactions. The crystalline metallosilicates can be selected from the group consisting of aluminosilicates, gallosilicates, ferrosilicates, titanosilicates and borosilicates.