Spectroscopic and Photophysical Behavior of 2-Quinolone as a Probe for Bronsted and Lewis Acid Sites in Zeolites

Bronsted and Lewis acid sites in zeolites were characterized by using 2-quinolone as a probe, by means of ultraviolet and infrared absorption spectra, fluorescence decay lifetime, and ESR. The results showed clearer differences in the acidity of zeolites compared to those determined by using Hammett indicators. The species observed in the zeolites depended on the acidity, the cavity size, and the amount of 2quinolone loaded.