Low temperature selective catalytic reduction of NOX with NH3 by activated coke loaded with FexCoyCezOm: The enhanced activity, mechanism and kinetics

The existing catalysts based on activated coke had generally poor denitration performance at low temperature, which could not meet the urgent needs of power plants and steel enterprises. In this study, activated coke loaded with FexCoyCezOm was prepared by incipient wetness impregnation method and employed to remove NOx at 100-350 degrees C in simulated flue gas. 3% Fe0.6Co0.2Ce0.2O1.57/AC catalyst exhibited highest NOx removal efficiency as it had more than 70% NOx conversion rate at 100 degrees C and achieved more than 90% denitrition efficiency at 250-350 degrees C. The catalyst also showed stable catalytic performance and good resistance to H2O or/and SO2 at 250 degrees C. Based on the results of Brunauer-Emmett-Teller (BET), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), temperature programmed desorption (TPD), temperature programmed reduction (TPR) and Fourier transform infrared spectroscopy (FTIR), the enhanced performance could be attributed to the co-participation of Fe, Co and Ce species with different valence states, the high concentration of chemisorbed oxygen, highly dispersed active components, the increase of weak acid sites, good redox properties of metallic oxides and abundant founctional groups on the catalyts surface. Finally, the possible mechanism and kinetics of NOx removal over FexCoyCezOm/AC catalyst were discussed in detail, which revealed that the enhanced performance was resulted from the increased active sites and the redox cycle among Fe, Co and Ce.