| abstract |
A nitrogen oxide storage catalyst comprising: a catalytic trap material comprising a catalytic component effective to promote the reduction of NOx under stoichiometric or rich conditions disposed on a refractory metal oxide support, and a NOx storage material effective for adsorbing NOx under poor conditions and desorbing and reducing NOx to nitrogen under stoichiometric or rich conditions, the NOx storage material comprising spray dried ceria particles having BaCO3 or a mixture of BaCO3 and MgCO3 supported on the particles of ceria, and a refractory carrier member, in which the catalytic trap material is disposed in the refractory support member, and in which the NOx storage material can be obtained by mixing a barium solution with the ceria particles, drying by spraying the particles, heating the spray dried particles and arranging the particles as a coating on a substrate. |