| 초록 |
Since selective catalytic reduction technology has been introduced to effectively remove NOx from automotive exhaust gases, many zeolites and metal oxides have been studied as SCR catalysts. However, these catalysts show very poor activity at low temperature below 200 oC, and they can not substantially remove NOx generated at cold start. Therefore, we have investigated the dual functional catalysts, various oxides are supported on CHA, which adsorb and store NOx below 200 oC, and desorbed at 300-400 oC. Furthermore, the Cu-ion exchanged dual catalyst consisting of the metal oxide and CHA, the nitrogen oxides adsorbed at low temperatures directly reduced and desorbed at a temperature over 300 oC, so that the SCR catalyst is possible to simultaneously perform two functions of NOx trap and reduction to remove. In this study, NOx adsorption-desorption behavior was investigated by TPD after loading CeO2, CaO, MgO, La2O3, and BaO as metal oxides impregnated on CHA. SCR activity was investigated after Cu-ion exchange for the effect of these metal oxides on reaction. |
