Patent ID: 9216381
Filing Date: 2015-12-22
Classification: B01D,B01J

Abstract:
1. A device for trapping nitrogen oxides (NOx), comprising a coating of a composition on a substrate, wherein the composition comprises alumina, cerium and a metal element M selected from the group consisting of barium, strontium and a combination of these two elements, wherein the metal element M is present in the composition in an amount of at least 10% by weight expressed as weight of oxide of the element M relative to the total weight of the composition, wherein the cerium is present in the composition in an amount between 2 and 15% by weight, inclusive, expressed as cerium oxide relative to the total weight of the composition, wherein the composition has a specific surface area of at least 90 m 2 /g after calcination at 900° C. for 2 hours, wherein the cerium is in the form of cerium oxide particles with a mean size of not more than 10 nm, after calcination in air at a temperature of 1000° C. for 2 hours, and with the proviso that the compound of formula MAl 2 O 4 is not detectable by X-ray diffraction in a composition after calcination in air at a temperature of 700° C. for 2 hours.