Characterization of silver species: Locations and environments in A, X, and Y zeolites by electron spin echo spectroscopy

Electron spin resonance and electron spin echo techniques are used to identify and characterize different types of isolated silver atoms observed on γ-irradiation of A, X, and Y zeolites. On the basis of 2D and 133Cs modulation analysis, the dominant species in A zeolites is located inside the β cage at a S2′ site and is coordinated to two waters. In X and Y zeolites, the Ag0 is found to be fully solvated by four waters and is located at the center of the β cage at site SU. Room temperature dehydration destroys the dominant species in A zeolites.