FT-IR evidence for the participation of protonic sites in the heterolytic cleavage of C-H bonds of methane over HZSM-5 zeolite

It has been observed by FT-IR spectroscopy that both kinds of Bronsted acid protons. present in HZSM-5 zeolite may be involved in the adsorption of methane at low temperature (173 K) and exchange with CH4 or CD4 at high temperature (> 500 degrees C). The-sites which can adsorb methane at low temperature are the active sites for methane conversion at high temperature. Over HZSM-5 zeolite, the activation of methane is suggested to occur via a heterolytic cleavage of C-H bond with the assistance of protons