Influence of Calcination Temperature on the NH₃–SCR Performance of CeTiO_<i>x</i> Catalysts Derived from Ce–Ti MOFs

In this paper, Ce–Ti MOFs were prepared by a hydrothermal method, and they were calcined at different temperatures for obtaining a series of MOFs-derived CeTiOx (denoted as CeTi-T) catalysts. The experimental results showed that the calcination temperatures imposed a significant impact on the SCR performance of CeTi-T catalysts. Particularly, nitrogen oxides conversion of CeTi-400 catalyst achieved more than 80% in a wide temperature range of 183–422 °C, and its N2 selectivity was almost 100% in a temperature range of 150–450 °C. Moreover, the CeTi-400 catalyst also exhibited excellent resistance to SO2/H2O. Various characterization results indicated that the CeTi-400 catalyst possessed more Ce–O–Ti species due to a strong interaction between Ce and Ti species. It resulted in a large specific surface area and more acidic sites but also brought about more abundant Ce3+ species and higher surface-adsorbed oxygen concentration. It was conducive for improving the NH3–SCR performance. The results of in situ DRIFTs suggested that NH3–SCR reactions over the CeTi-400 catalyst followed both L–H and E–R mechanisms.