Investigation of SO2 tolerance of Ce-modified activated semi-coke based catalysts for the NO plus CO reaction

摘要

Activated semi-coke was loaded with Fe-Co mixed oxides and doped with an optimized amount of cerium oxides. This prepared catalyst exhibited excellent NO removal (deNO) activity, and also showed outstanding SO2 resistance at 250 degrees C. To understand the SO2 tolerance mechanism, the catalysts were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, in situ Fourier-transform infrared spectroscopy, H-2-temperature- programmed reduction, and SO2-temperatureprogrammed desorption, as well as CO-deNO activity testing under different conditions. The results indicate that the Ce (molar ratio = 0.1) doped onto the Fe-Co binary oxide catalysts would promote the generation of Ce-2(SO4)(3). This generation could prevent the active metal oxides from being poisoned by SO2. Furthermore, this kind of sulfate would weaken the interaction between SO2 and NO, so that the adsorbed NO will have a better opportunity to react with CO.