Electron paramagnetic resonance studies of the formation of alkali-metal particles and ionic clusters in alkali-metal-loaded X zeolites

Abstract

Alkali metals (Li, Na, K, Rb, Cs) are loaded into the corresponding alkali-metal cation-exchanged X zeolites by alkali-metal vapour exposure and by decomposition of the corresponding alkali-metal azide mixed with the zeolite. Electron paramagnetic resonance shows that alkali-metal ionic clusters are formed, with K²⁺₃ ionic clusters being reported for the first time in the potassium cation-exchanged X zeolites. Analysis shows that the number of nuclei in the alkali-metal ionic cluster is determined by the distribution of cations in the β-cage of the zeolite structure. Alkali-metal particles are also formed by both methods and are characterized by electron paramagnetic resonance.