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 (Ce_aTi_1−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 Ce_aTi_1−a catalysts were characterized by means of XRD, Raman, TEM, N₂-sorption, XPS, H₂-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 Ce_aTi_1−a catalysts. As results, the Ce_aTi_1−a catalysts exhibited excellent redox ability, enrichment of Ce³⁺ species, high surface adsorbed oxygen concentration, and abundant acid sites. The Ce_aTi_1−a catalysts showed remarkable catalytic activity with broad operation temperature window, and Ce_0.5Ti_0.5 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.