Effectively promoted catalytic activity by adjusting calcination temperature of Ce‐Fe‐O_x catalyst for NH₃‐SCR

Abstract

A series of Ce‐Fe‐Ox catalysts prepared by the different calcination temperatures (marked as CF‐X, where X represented calcination temperature) were used to the selectivity catalytic reduction of NOx by NH3. The results explained the relationship between calcination temperature and the sulfate species over Ce‐Fe‐Ox, and then investigated the surface acidity and catalytic performance. The large amounts of sulfate species were formed over CF‐450 and CF‐550 while it was decomposed with further the increasing of calcination temperature, which resulted in the loss of surface acidity, causing a decrease in the catalytic activity over Ce‐Fe‐Ox. Thereby, the CF‐450 catalyst showed the best catalytic activity and over 90% NOx conversion was obtained at 244–450 °C. Besides, the favored pore structure, more Fe3+ active species, higher Ce3+ concentration and the abundance of chemical adsorbed oxygen species, as well as the surface acid sites, would together contribute to the excellent catalytic activity of CF‐450 catalyst.

Effect of CaCO3on catalytic activity of Fe–Ce/Ti catalysts for NH3-SCR reaction

“…For this purpose, many catalysts containing metal oxides have been found to possess high catalytic activity for SCR reaction including Fe, Ce, Mn, and Cu based catalysts. [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] Based on our previous study, we found the Fe-Ce/Ti catalysts could exhibit high catalytic activity for the NH 3 -SCR reaction. However, there are several components in the real ue gases including K, Ca, CO 2, and SO 2 , which will lead to the physical or chemical deactivation of catalysts and thus restrict the industrial application of catalysts.…”

Promotional effect of ceria on the catalytic behaviour of new V2O5–WO3–TiO2 aerogel solids for the DeNOx process

“…As it can be seen the strength and the number of acid sites are clearly affected by the type of the elements added to titania oxide. So, the highest total acidity is obtained in the case of V 2 O 5 -WO 3 -TiO 2 catalyst which displays the most intense and large NH 3 desorption peaks between 100 and 550 °C corresponding to the ammonia desorbed from weak, medium and strong acid sites [47,65]. As shown also in Fig.…”

Promoting effect ofN2calcination onFeCeOxfor selective catalytic reduction ofNOxwithNH3

“…O ɑ is more active than O ⊎ due to its mobility. 42,43 Suitable improvement of the O ɑ proportion was helpful for NO x conversion.…”

“…Considering the results of XRD and H 2 ‐TPR, it was believed that more oxygen vacancies formed in Fe 9 CeO x ‐N 2 , resulting in more surface‐adsorbed oxygen species. O ɑ is more active than O β due to its mobility 42,43 . Suitable improvement of the O ɑ proportion was helpful for NO x conversion.…”