Influence of Calcination Temperature on the NH<sub>3</sub>–SCR Performance of CeTiO<sub><i>x</i></sub> Catalysts Derived from Ce–Ti MOFs

In this paper, Ce–Ti MOFs\nwere prepared by a hydrothermal\nmethod, and they were calcined at different temperatures for obtaining\na series of MOFs-derived CeTiO<sub><i>x</i></sub> (denoted\nas CeTi-T) catalysts. The experimental results showed that the calcination\ntemperatures imposed a significant impact on the SCR performance of\nCeTi-<i>T</i> catalysts. Particularly, nitrogen oxides conversion\nof CeTi-400 catalyst achieved more than 80% in a wide temperature\nrange of 183–422 °C, and its N<sub>2</sub> selectivity\nwas almost 100% in a temperature range of 150–450 °C.\nMoreover, the CeTi-400 catalyst also exhibited excellent resistance\nto SO<sub>2</sub>/H<sub>2</sub>O. Various characterization results\nindicated that the CeTi-400 catalyst possessed more Ce–O–Ti\nspecies due to a strong interaction between Ce and Ti species. It\nresulted in a large specific surface area and more acidic sites but\nalso brought about more abundant Ce<sup>3+</sup> species and higher\nsurface-adsorbed oxygen concentration. It was conducive for improving\nthe NH<sub>3</sub>–SCR performance. The results of in situ\nDRIFTs suggested that NH<sub>3</sub>–SCR reactions over the\nCeTi-400 catalyst followed both L–H and E–R mechanisms.