The present invention relates generally to zeolites having a silica/alumina ratio of less than or equal to 10 (Si/Al≦10) that are exchanged with Ag+ and thermally treated in such a way to favor adsorption over alternative catalytic and chemically reactive functionalities. The adsorbents of the present invention and the method of producing such adsorbents maximize the working adsorption capacity through π-complexation. Applications for such adsorbents include any process in which contaminants from gas streams can form π-complexes with the Ag in the zeolite, particularly the removal of CO, ethylene, propylene and the like from air and CO/H2 from air in prepurifier adsorbers in the production of ultra high purity (UHP) N2.