Morphology and crystal–plane dependence of CeO2–TiO2 catalysts: Activity and mechanism for the selective catalytic reduction of NO with NH3

Improved NH3-SCR activity by the cooperation of FeVO4 and CeO2 nanosheet catalysts: structure and mechanism

“…The higher Ce 3+ ratios could generate more oxygen vacancies and thus promote the SCR reaction process. 18 The Ce 3+ ratios of the catalyst samples are shown in Table 3 and follow the sequence 5%FeV/CeO 2 -S > 10%FeV/CeO 2 -S > 15%FeV/CeO 2 -S > 20%FeV/CeO 2 -S > 10%FeV/CeO 2 -P, which is in accordance with XRD results. Related research pointed out that lower crystallinity would lead to lower formation energy of materials, and thus more oxygen vacancies are generated.…”

“…When NH 3 was introduced, the observed bands of adsorbed NH 3 species corresponded to coordinated NH 3 on Lewis acid sites (1593, 1551, 1535 and 1197 cm −1 ), the NH 4 + species on Brønsted acid sites (1666 and 1420 cm −1 ) and amide species (1354 and 1321 cm −1 ). 4,18,47 There was no significant difference between the adsorbed NH 3 species and their peak intensity shown in Fig. S11a and that in Fig.…”

“…9a and b, after NH 3 adsorption and N 2 purge, the observed bands of adsorbed NH 3 species corresponded to coordinated NH 3 on Lewis acid sites (1593, 1551, 1533, 1234 and 1204 cm −1 ), NH 4 + species on Brønsted acid sites (1666 and 1420 cm −1 ) and amide species (1356 and 1329 cm −1 ). 4,18,47 As shown in Fig. S13a,† the NH 3 species adsorbed on CeO 2 -S were basically the coordinated NH 3 on Lewis acid sites (1593, 1568, 1550 and 1294 cm −1 ).…”

“…S11b,† which meant that the adsorption of NH 3 was less influenced by O 2 than that of NO x . 18 10%FeV/CeO 2 -S was exposed to NH 3 + NO + O 2 for 30 min and then purged with N 2 at 250 °C; the spectra are shown in Fig. S12 †.…”

Improved K-Resistance of a Cu-Modified TiO2/CeO2 Catalyst for SCR of NOx at Low Temperatures

“…Thus, the reduction behavior of the obtained catalysts was characterized via H 2 -TPR. As shown in Figure , three broad peaks at 403, 545, and 750 °C were observed on pristine Ti/Ce and marked as peaks I, II, and III, which was attributed to the reduction signal of surface active oxygen, surface Ce–O–Ti species, and bulk CeO 2 species along with the reduction of TiO 2 , respectively. , After K poisoning, these reduction peaks shifted to a higher temperature orientation, suggesting a weakened reducibility of the Ti/Ce sample. After CuO modification, peaks I and II appeared at a much lower temperature.…”