Development of AEI-type boroaluminosilicate zeolites, and their acidic and catalytic properties in ethene conversion reaction

Abstract

Incorporation of B atoms into the AEI-type framework was successfully achieved by addition of boric acid into the starting gel. The gel compositions, the Si/Al and Si/B ratio, and the calcination conditions were extensively investigated to tune acidic properties of the AEI-type zeolite. The incorporation of B into the framework was confirmed by solid state NMR and FT-IR techniques. In-situ FT-IR spectroscopy using CO as a probe molecule was applied to the evaluation of the acidic property. As the result of in-situ FT-IR measurement, thus obtained AEI-type boroaluminosilicate zeolites showed weak acidic properties derived from framework B species compared to the aluminosilicate one. Finally, the catalytic properties of the synthesized AEI-type zeolites in the ethene conversion reaction were investigated. We found that the AEI-type boroaluminosilicate catalyst showed a long catalytic life and a high selectivity to butenes.