Influence of Calcination Temperature on the NH3-SCR Performance of CeTiO x 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 CeTiO x (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 degrees C, and its N-2 selectivity was almost 100% in a temperature range of 150-450 degrees 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.