Some unusual properties of activated and reduced AgNaA zeolites

Abstract

Carbon monoxide, oxygen and hydrogen were found to be chemisorbed on dehydrated AgA zeolites. This was investigated in detail using volumetric sorption and temperature programmed desorption techniques. Also i.r. and mass spectrometry were used to characterize the solid and the desorbed molecules.

It was found that as a result of an auto-reductive process, colour centres are created upon degassing of the zeolite. These centres sorb hydrogen and oxygen dissociatively, while one molecule of carbon monoxide was chemisorbed per Ag ion available in the supercage. It is proposed that linear Ag⁺₃ clusters are formed upon activation, the ends of which constitute chemisorption sites for hydrogen and oxygen.