Simultaneous removal of NO and Hg° using Fe and Co co-doped Mn-Ce/TiO_2 catalysts

摘要

Fe and Co co-doped Mn-Ce/TiO2 (MCT) catalysts were investigated for the simultaneous removal of nitric oxide ( NO) and elemental mercury (Hg-0) at reaction temperature lower than 200 degrees C. The catalysts were characterized by Brunauer-Emmett-Teller ( BET), temperature program reduction (TPR), scanning electron microscope (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis. The experimental results showed that the co-doped 2Fe4Co-MCT catalyst exhibited better performance for the simultaneous removal of NO and Hg-0 compared to Fe or Co doped catalysts. This could be due to higher BET surface area and better redox property of 2Fe4Co-MCT catalyst. In addition, we propose that chemisorbed O-2 played a dominant role in selective catalytic reduction (SCR) of NO while lattice O-2 played a key role in Hg-0 oxidation. The results also indicate that the introduction of Fe species enhanced the activity of SCR, whereas the introduction of Co species enhanced the oxidation of Hg-0. The synergistic effect of Fe and Co species in the 2Fe4Co-MCT catalyst are also suggested to be an important mechanism for simultaneously removing NO and Hg-0.