Radiolytic hydrogen gas formation from water adsorbed on type Y zeolites

Hydrogen molecules (H2) and atoms (H) formed by 60Co γ-ray irradiation of type Y zeolites adsorbing various amounts of water were measured by means of gas chromatography and ESR spectroscopy. The enhancement of H2 formation due to energy transfer from the zeolites to adsorbed water was observed. The discussion on H and H2 formation by energy transfer was made based on the comparison of G(H2) and G(H) between NaY- and HY-water system. The dependence of G(H2) upon preheating temperature of zeolites implied that both Broensted acidic nature of hydroxyls and Lewis sites formed during dehydroxylation influence the H2 and H yield in the HY-water system. (author)