Patent ID: 6309617
Filing Date: 2001-10-30
Classification: B01D,F01N,Y02T

Abstract:
A method of treating a gas comprising nitrogen oxides, comprising:controlling cycling of the .lambda.-value of the gas to alternate in a predetermined manner between a .lambda.-value that is greater than 1 and a .lambda.-value that is less than or equal to 1;storing nitrogen oxides in a solid when the .lambda.-value of the gas is greater than 1; andreleasing said stored nitrogen oxides when the .lambda.-value of the gas is less than or equal to 1,wherein the .lambda.-value is a ratio of oxidizing constituents to reducing constituents contained in said gas,wherein the solid consists of a material selected from the group consisting of Ag.sub.2 O, Ag.sub.2 CO.sub.3 and AgOH; at least one other precious metal; and a microporous carrier substance.