| 摘要 |
<p>The invention concerns materials for eliminating nitrogen oxides NO and NO2 present in exhaust gases, in particular of motor vehicle internal combustion engines operating in a medium containing oxidants above stoichiometric level, capable of adsorbing the nitrogen oxides, then capable of desorbing the nitrogen oxides by a rise in temperature, relative to the adsorption temperature or by treatment in rich mixture, said materials comprising mixed oxides including metals in octahedral co-ordination, octahedra which link up so that the structure is laminated. Said materials adsorb nitrogen oxides by insertion and are not poisoned when in contact with sulphur or carbon oxides contained in the gases. In the presence of a metal of group VIII, said materials are capable of eliminating nitrogen oxides adsorbed by reduction when treated in rich mixture.</p> |
