| 摘要 |
The invention relates to a method for removing carbon monoxide and hydrocarbons from the exhaust gas of lean-burn internal combustion engines, said exhaust gas being passed over a catalyst which contains platinum supported on one or more refractory supporting materials, pure cerium oxide, and optionally an additional noble metal selected from the group consisting of platinum, palladium and rhodium, wherein the pure cerium oxide is in close contact with the noble metal. |
| 主权项 |
1. A method for removing carbon monoxide and hydrocarbons from the exhaust gas of lean-burn internal combustion engines, wherein the exhaust gas is passed over a catalyst which contains
(i) platinum supported on one or more refractory supporting materials, (ii) pure cerium oxide, and, if the ratio of platinum to cerium oxide is ≦0.5 (calculated as Pt in f/cft:cerium oxide in g/l), (iii) an additional noble metal selected from the group consisting of platinum, palladium, rhodium and mixtures thereof,
the pure cerium oxide (ii) being in close contact with platinum (i) and, if included, additional noble metal (iii),wherein, after a limit temperature exposure under lean exhaust gas conditions is exceeded, the catalyst is exposed for a short time to rich exhaust gas to regenerate catalytic activity. |
