Reactions of Oxygen Atoms with Zeolite‐4A Studied in a Flow System by ESR‐Spectroscopy

Abstract

During and after the reaction of O‐atoms with zeolite‐4A two paramagnetic centers of equal concentration are observed. One species is identified as an O2−radical adsorbed on a silicium atom in the zeolite surface. The other center, discussed here for the first time, is described as an O−‐radical stabilized on an aluminum atom of the zeolite structure. The ESR‐data of that new center (g⊥ = 2.012, g∥ = 2.007, aiso = 15.1 Gauss) support that interpretation rather well. A mechanism for the formation of both paramagnetic species is suggested.

ESR Studies on the Interaction of Molecular/Atomic Oxygen and Ethylene with Silver Zeolites

“…Recently, it has been urged in a review article [3] that accumulation of further evidence on the role of adsorbed molecular and atomic oxygen species is particularly desirable. Since in our group the reaction of atoms with oxide surfaces [4] and with zeolite-4 A [5] had been studied earlier, it was promising t o investigate the direct interaction of oxygen atoms with the dehydrated as well as with the metal loaded silver zeolites.…”