Adsorption of pyridine on dealuminated zeolite HY

Abstract

Infrared spectra showed that over 80% of aluminum atoms on the surface of zeolite HY were extracted by a exposure of SiCl₄ vapor at elevated temperatures. The dealumination of the HY surface resulted in an appreciable change in its acidic properties. Infrared spectra of adsorbed pyridine indicated the formation of various kinds of Lewis acid sites on the delauminated HY surfaces. Although the total number of the surface Bronsted acid site decreased in the SiCl₄‐induced dealumination process, the nature of these remaining Brø nsted acid sites was unchanged spectroscopically.

Key words:

• Dealumination
• pyridine
• VOCs
• FTIR
• adsorption