| 초록 |
It has been reported that N2O causes a various environmental problems such as global warming and depletion of the stratospheric ozone layer. NOx removal is usually achieved by SCR technology using reductants such as NH3, CO and H2. However, N2O reduction to N2 is much more difficult to achieve. This study deals with simultaneous catalytic reduction of NO and N2O over a commercial Pd/Rh catalyst, where H2 and/or CO are used as a reductant. Conversion of NO and N2O is significantly dependent on O2 concentration in the mixture of NO and N2O. High conversion of NO and N2O is shown at low O2 concentration. In absence of O2, higher conversion of NO and N2O than 50 % can be obtained at the temperatures higher than 150 oC in using H2 but 300 oC in using CO. It is worth noting that the high conversion of NO and N2O is remained even at the temperatures over 400 oC. However, the presence of O2 in NO and N2O decreases the catalytic reduction of NO and N2O at the high temperatures, which probably results from that the reductants are consumed by their oxidation rather than the reduction of NO and N2O. The increase of NO concentration in reactants slightly lowers the conversion of NO and N2O. |
