| 초록 |
This study has been focused on N2O formation upon changes in surface compositions in an on-site-used V2O5-WO3/TiO2 catalyst using acid washing and active component addition techniques. The catalyst after on-site-use in a power plant showed decrease in surface area, and a shift of pore size distribution toward larger size. Vanadium amounts in the spent catalyst increased by 1%, and the vanadium oxide existed in the form of polycrystalline nanoparticles. The indicated changes in the physicochemical properties before and after on-site-use could lead to the noticeable difference in the N2O production in the NH3-SCR reaction. An acid washing of the used sample yielded N2O production similar to that of a fresh catalyst, while the formation of N2O approaching that over the spent catalyst was measured when 1% V2O5 was added to the fresh sample. XRF and ICP measurements gave the presence of MoO3 with significant amounts in the used catalyst. Consequently, it is clear that such alien metals, mainly vanadium and molybdenum oxides, play a key role in creating a huge quantity of N2O production. |
