Elucidate the promotional effects of Sn on Ce-Ti catalysts for NH3-SCR activity. Issue 3 (June 2020)

• Record Type: Journal Article
• Authors: Gong, Pijun; Xie, Junlin; Cheng, Xiangkui; Fang, De; He, Feng; Li, Fengxiang; Qi, Kai
• Is Part Of: Journal of the Energy Institute. Volume 93:Issue 3(2020)
• Page Start: 1053
• Page End: 1063
• Publication Date: 2020-06
• Subjects: Ce0.3-x-Snx-Ti -- Redox equilibrium -- Mesoporous -- NH3-SCR -- Reaction mechanism; Power (Mechanics) -- Periodicals; Power resources -- Periodicals; Fuel -- Periodicals; 621.04205
• DOI: 10.1016/j.joei.2019.09.006
• Languages: English
• ISSNs: 1743-9671

Abstract

Abstract: Through a facile hydrothermal method, a series of mesoporous Ce0.3-x -Snx -Ti catalysts with high surface area have been prepared. A lot of characterizations were used to elucidate the promotional effects of SnO2 on Ce0.3 -Ti catalysts for NH3 -SCR activity. Compared with CeO2 –TiO2 catalysts, the activity and SO2 resistance of the Ce0.2 -Sn0.1 -Ti catalyst were remarkably improved after doping Sn, and presented an excellent catalytic activity (above 90%) within 220–360 °C. The results suggested that Sn-doped Ce–Ti catalysts effectively increased lattice oxygen mobility, total acid amount accompanied with more Ce 3+ and surface adsorbed oxygen species by insertion of doping ions. Furthermore, the reducibility of Ce0.2 -Sn0.1 -Ti sample was greatly improved by the reaction of 2Ce 4+ + Sn 2+ ↔ 2Ce 3+ + Sn 4+, and with the assistance of Ce2 O3 to prevent the (NH4 )2 SO4, NH4 HSO4 species and bulk-like sulfates from forming on the surface, leading to the better SO2 resistance. In addition, the in situ DRIFTS also illustrated that the NH3 -SCR process occurred over Ce0.2 -Sn0.1 -Ti obeyed the Elye-Rideal mechanism. Graphical abstract: Image 1 The Ce0.2 -Sn0.1 -Ti catalyst presents an excellent catalytic activity (above 90%) at 220-360 o C and better SO2 tolerance. Doping SnO2 to Ce-Ti catalyst promote form much more Ce 3+, which can increase the oxygen vacancy and total acid amount of the catalysts. Meanwhile the reducibility of Ce0.2 -Sn0.1 -Ti sample was greatly improved by the reaction of 2Ce 4+ + Sn 2+ ↔ 2Ce 3+ +Sn 4+ . Highlights: With a facile hydrothermal method, a series of high surface area mesoporous Ce-Sn-Ti catalysts have been prepared. The Ce0.2 -Sn0.1 -Ti catalyst presents an excellent catalytic activity (above 90%) at 220-360 °C and better SO2 tolerance. Sn doped to Ce-Ti catalysts effectively increase lattice oxygen mobility, total acid amount accompanied by insertion of doping ions. The redox equilibrium by 2Ce 4+ + Sn 2+ ↔ 2Ce 3+ + Sn 4+ may be the reasion lead to the better SO2 tolerance.