Patent ID: 7319082

Claim:
A process for preparing a molecular sieve adsorbent for selective adsorption of oxygen from air, the process consisting essentially of: (i) exchanging zeolite X with water-soluble salt of a rare earth metal selected from the group consisting of cerium, europium, gadolinium and any mixture thereof; (ii) filtering the mixture, washing the powder or pellet with heated distilled water until it is free from anions to obtain an exchanged zeolite; (iii) drying the exchanged zeolite; (iv) and activating the exchanged zeolite at the temperature range of 350 to 450° C. for a period in the range of 3-6 hours followed by cooling under inert or vacuum, wherein Na cations of zeolite are exchanged with salts of the rare earth metals selected from chloride, nitrate and acetate, wherein the cation exchange is carried out at a temperature in the range of 30° C. to 90° C. for a period in the range of 4 to 8 hours, and wherein the adsorbent has adsorbence up to 850 mm Hg.