Far-infrared study of metal particle formation in alkali-metal cation-exchanged X zeolites exposed to sodium vapour

Abstract

Dehydrated alkali-metal cation-exchanged X zeolites were reacted with sodium metal vapour and studied by far-infrared spectroscopy. Infrared evidence for electron transfer between sodium atoms and the exchanged cations in zeolites is found in Li-X, Na-X and K-X. Infrared band shifts for larger cation-exchanged zeolites such as K-X, Rb-X and Cs-X are observed and are also consistent with electron transfer from sodium atoms. These shifts are suggested to be caused by the diffusion of sodium metal atoms to the cation location sites. The conclusions about electron transfer from sodium vapour are in good agreement with electron paramagnetic resonance studies on the same systems.