Patent ID: 6632768
Filing Date: 2003-10-14
Classification: B01D,B01J,F01N,Y02T

Abstract:
An adsorbent for hydrocarbons (HC) in an exhaust gas, comprising an agglomerate of double-structure particles, each of which includes an HC-adsorbing zeolite core, and a ceramic coat wrapping said zeolite core and having a plurality of through-pores communicating with a plurality of pores in said zeolite core, wherein each of said double-structure particles is at least one of a double-structure particle including said zeolite core comprising a single zeolite particle, and a double-structure particle including said zeolite core comprising a plurality of zeolite particles, and each of said plurality of through-pores in said ceramic coat has such a bottleneck shape with an opening narrowed down that the HC is easy to flow into said through-pore and difficult to flow out of said through-pore.