Purification of gases in H-mordenite modified with silane and diborane

Abstract

Silane and diborane have been found to be very suitable for the structural modification of H-zeolites, and stepwise boranation of the H-mordenite structure has been studied. The effect of the degree of modification on the pore size and the affinity of the zeolite was checked by sorption experiments with N₂(77 K) and Xe and Kr (273 K). A further narrowing of the pore size was achieved by oxidation of the implanted (BH)_x groups with H₂O or other molecules such as CH₃OH. The pore size could be ‘engineered’ in a controlled way so that it could be applied to finely tuned separations, yielding components of pure Kr from Kr + N₂, Ar + Kr, O₂+ Kr and N₂+ O₂+ Kr, pure Ar from Ar + Kr, pure N₂ from N₂+ Kr, pure O₂ from O₂+ Kr and pure CH₄ from H₂+ N₂+ CH₄ mixtures.