Interzeolite Conversion of FAU Type Zeolite into CHA and its Application in NH3-SCR

Abstract

In this work we studied the potential feasibility to synthesize small pore zeolites, such as chabazite (CHA) via interzeolite conversion of FAU type zeolite. We have thereafter used CHA as the starting material to obtain Cu–CHA. When CHA in NH4+ form was used to prepare Cu–CHA, the large size of the potassium cation present in the structure caused pore blockage in the chabazite framework, and diminished the adsorption and exchange capacity. However, Cu–CHA with comparable Selective Catalytic Reduction performance to the commercial catalyst was obtained via ion exchange if Cu-exchange was performed from H+–CHA form. Still, the main challenge was to fully eliminate K+ from the zeolite structure in order to further improve its catalytic performance and high temperature stability.