| 摘要 |
PROBLEM TO BE SOLVED: To further improve the reduction efficiency and further cut the NOx amount exhausted without being completely reduced in a stoichiometric-to-rich atmosphere of fuel in the high temperature zone. SOLUTION: A CO modification catalyst is arranged at the upstream side of an exhaust gas flow channel and an NOx occlusion/reduction-type catalyst is arranged at the downstream side of the CO modification catalyst. H2 is formed from CO and H2O contained in an exhaust gas in the stoichiometric-to- rich atmosphere of fuel with the help of the CO modification catalyst. The reduction activity of the formed H2 is extremely higher than that of the HC or CO, so that the reduction efficiency of the NOx by the NOx occlusion/ reduction-type catalyst is enhanced. |
