Precisely fabricating Ce-O-Ti structure to enhance performance of Ce-Ti based catalysts for selective catalytic reduction of NO with NH3

A series of Ce-Ti mixed oxides (CeaTi1-a) were successfully synthesized by a spontaneous deposition method and evaluated in selective catalytic reduction of NO with NH3 (NH3-SCR). The structures and properties of the CeaTi1-a catalysts were characterized by means of XRD, Raman, TEM, N-2-sorption, XPS, H-2-TPR and NH3-TPD. The results demonstrated that lots of Ce-O-Ti species were formed because of the strong synergistic interaction of gelation of TiO2 and deposition of Ce3+ during the preparation process of CeaTi1-a catalysts. As results, the CeaTi1-a catalysts exhibited excellent redox ability, enrichment of Ce3+ species, high surface adsorbed oxygen concentration, and abundant acid sites. The CeaTi1-a catalysts showed remarkable catalytic activity with broad operation temperature window, and Ce0.5Ti0.5 catalyst exhibited the best catalytic activity and extraordinary H2O/SO2 durability. The in-situ FTIR results revealed that the mechanisms of L-H and E-R existed synchronously during the NH3-SCR reaction, and the former one was predominant due to its rapid reaction rate.