It is shown by in situ ESR studies that H2 reduction of dehydrated AgA‐ and AgX‐zeolites proceeds via intermediate formation of Agn+6 (n < 6) clusters, located inside the cubooctahedral sodalite cages. On further reduction, submicroscopic Ag crystals (<5 nm) are formed, resulting in a conduction electron spin resonance signal. At higher temperatures (T > 200°C) crystal growth leads to larger crystallites (10–50 nm) as indicated by x‐ray line broadening.

No 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.

Während und nach der Reaktion von O‐Atomen mit Zeolith‐4A werden zwei paramagnetische Zentren von gleicher Konzentration beobachtet.