Method for preparing the silicoaluminate form of the AEI zeolite structure with high yields, and its application in catalysis

摘要

A synthesis process for a crystalline material with the AEI zeolite structure, comprising (i) preparation of a mixture containing, at least, water, one zeolite with the FAU crystal structure as the only source of silicon and aluminum, a cyclic ammonium cation with alkyl substituents as the OSDA, and a source of alkaline or alkaline-earth cations (A), wherein the synthesis mixture has the following molar composition: SiO₂:a Al₂O₃:b OSDA:c A:d H₂O where a ranges between 0.001 and 0.2; where b ranges between 0.01 and 2; where c ranges between 0 and 2; where d ranges between 1 and 200; and wherein the mixture is free from phosphorous and fluorinated species, (ii) crystallisation of the mixture and, (iii) recovery of the crystalline material. Also, preparation of catalysts based on the AEI zeolite and application as a catalysts in processes including the selective catalytic reduction of NO_x.