Enhanced Low-temperature NH3-SCR Activity over Ce-Ti Oxide Catalysts by Hydrochloric Acid Treatment

Abstract

The effect of hydrochloric acid treatment on Ce-Ti oxides was investigated for selective catalytic reduction of NO with NH 3. The results showed that hydrochloric acid treatment had a positive effect on the low-temperature activity of Ce-Ti oxides. The improved activity of Ce-Ti oxides could be attributed to the increase in the concentration of Ce as well as the amount of Ce 3+ and chemisorbed oxygen on the catalyst surface. In addition, the enhanced Lewis acidity could improve NH 3 absorption, and was also a key factor to enhance the low-temperature activity of Ce-Ti oxides.

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.…”

Agricultural Waste Derived Catalysts for Low Temperature SCR Process: Optimization of Preparation Process, Catalytic Activity and Characterization

“…Carbon materials, including activated carbon, graphene, carbon nanotubes etc., have found wide application for use in low temperature SCR, because of their high specific surface areas and chemical stability (Marban et al, 2004;Lu et al, 2010;Zhu et al, 2011;Jiao et al, 2015;Yu et al, 2015). In particular, the manganese oxide catalysts have attracted great attention, because they contain various types of labile oxygen and oxidation states of Mn (Jiang et al, 2019b;Zhang et al, 2019;Tong et al, 2020;Wang et al, 2020). This improves the feasibility of the use of these catalysts to complete the catalytic cycle in low temperature NH3-SCR.…”

Recent Progress of CeO2−TiO2 Based Catalysts for Selective Catalytic Reduction of NOx by NH3

“…A study conducted by Jiang et al. found that similar enhancement can be obtained by treating Ce−Ti sample with desired aqueous hydrochloric acid solution [97] . Since CeO 2 −TiO 2 sample is also a good photocatalyst, thus we have adopted a photo‐treatment to enhance its NH 3 −SCR activity [21b,98] .…”

“…A study conducted by Jiang et al found that similar enhancement can be obtained by treating CeÀ Ti sample with desired aqueous hydrochloric acid solution. [97] Since CeO 2 À TiO 2 sample is also a good photocatalyst, thus we have adopted a photo-treatment to enhance its NH 3 À SCR activity. [21b,98] For CeO 2 /TiO 2 catalyst, photo-treatment can induce a stronger interaction between CeO 2 and TiO 2 and the formation of new oxygen vacancies and Ce 3 + ions.…”