Patent ID: 8802044

Claim:
A filtration structure, comprising: an array of longitudinal adjacent channels of mutually parallel axes separated by porous filtering walls comprising a porous inorganic material, wherein said channels are alternatively plugged at one or other of the ends of the structure so as to define inlet channels and outlet channels for a gas comprising NO x to be filtered, and so as to force said gas to pass through the porous filtering walls separating the inlet channels from the outlet channels, wherein said filtration structure comprises a catalytic system comprising at least one noble metal or transition metal that reduces the NO x and a support material wherein the support material has formula (I): (ZrO 2-x ) 1-y (M 2 O 3-x ) y (I), wherein: M is Y 3+ , Sc 3+ , or a rare earth cation of valency 3; x is greater than 0.005 and less than 0.5; and y is greater than 0 and less than 2; or wherein the support material has formula (II): (ZrO 2-x ) 1-y′ (M′O 1-x ) y′ (II), wherein: M′ is Ca 2+ or Sr 2+ ; x is less than 0.5; and y′ is greater than 0 and less than 2.