| 초록 |
FeOx-promoted V2O5-WO3/TiO2 catalysts for the selective reduction of NO by NH3 (NH3-SCR) have been investigated to examine a role of the FeOx species in removing the NO and controlling side reactions. Desired amounts of FeOx were added to a 1.6% V2O5 on 10% WO3/TiO2 (WT), referred to as FeOx/VWT. The VWT showed ca. 90% NO conversion at 350°C after which the activity decreased with temperature. This sample gave about 25 ppm for N2O at 450°C, depending stongly on temperature, but the extent of N2O production at high temperatures could be greatly depressed by the presence of FeOx. NH3 TPD studies disclosed that the FeOx plays a main role in suppressing the oxidation of NH3 into N2O thereby yielding a lesser N2O formation over FeOx/VWT catalysts. Such a role was independent of the oxidation states of Fe species, since a similar conclusion could be reached from a VWT catalyst with Fe-zeolite. |
