G. Peeters

Microprobe analysis of noble gas encapsulates in zeolites

Abstract Electron microprobe analysis has been employed for the first time to investigate gases immobilized in zeolites. Two trapping procedures and two different molecular sieves were tested: on one hand Kr as well as one to one Xe Kr and Xe Ar mixtures were trapped hydrothermally in X-ray amorphous zeolite 5A, and on the other, Kr was immobilized in mordenites by a combination of physical sorption and chemical modification procedure. The results show that the noble gases Ar, Kr and Xe can be quickly and specifically identified in these inorganic matrices. Because in all samples the density of the noble gas follows exactly the density of the aluminosilicate framework it is concluded that the noble gas is homogeneously distributed in the zeolite material. Analysis of noble gas mixtures indicates that each of the noble gases Ar, Kr and Xe can be specifically monitored in the presence of the two others. In addition, an analysis of other elements present in the pellet can be simultaneously carried out. The variation of the concentration of these elements with structure can be followed with resolution of ≈ 1μm.