ESR Studies on the Reduction Process of Silver Zeolites

It is shown by in situ ESR studies that H2reduction 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.