Effect of Promoters (Co, Cr, Fe, Zr) on the Performance of MnO2/CeO2 Catalysts for NO Reduction at Low Temperatures Using NH3-SCR

This study examined the effect of various promoters (Co, Cr, Fe, Zr) in reducing NO using the NH3-SCR reaction on the MnO2/CeO2-Nanorod catalysts. The physicochemical properties of these catalysts were characterized using Brunauer-Emmett-Teller, X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscope, scanning electron microscope-energy dispersive X-ray spectroscopy, and Raman spectroscopy. Characterization analysis revealed uniform dispersion of active metals on CeO2-Nanorod supports, desired active metal-support synergism, small crystallite sizes, high specific surface areas, and an appreciable amount of surface lattice oxygen in Co-MnO2/CeO2-Nanorod catalysts. Co-MnO2/CeO2-Nanorod catalyst showed the best NH3-SCR activity at low temperatures. The NO conversion and N-2 selectivity are 87 and 85%, respectively, at 300 degrees C with excellent stability. The Co-MnO2/CeO2-Nanorod catalyst also showed excellent tolerance against the H2O and the SO2. The catalyst's performance can be attributed to its high surface area, oxygen storage capacity, high Ce3+ content, and evenly distributed promoters.