Thulium modified MnOx/TiO2 catalyst for the low-temperature selective catalytic reduction of NO with ammonia. (25th March 2021)

• Record Type: Journal Article
• Authors: Niu, Cihang; Wang, Baorui; Xing, Yi; Su, Wei; He, Chi; Xiao, Lei; Xu, Yurong; Zhao, Shuqi; Cheng, Yonghong; Shi, Jian-Wen
• Is Part Of: Journal of cleaner production. Volume 290(2021)
• Publication Date: 2021-03-25
• Subjects: NH3-SCR reaction -- Thulium -- Manganese -- De-NOx -- Low temperature; Factory and trade waste -- Management -- Periodicals; Manufactures -- Environmental aspects -- Periodicals; Déchets industriels -- Gestion -- Périodiques; Usines -- Aspect de l'environnement -- Périodiques; 628.5
• DOI: 10.1016/j.jclepro.2021.125858
• Languages: English
• ISSNs: 0959-6526

Abstract

Abstract: A new thulium (Tm) modified Mn/TiO2 catalyst is firstly prepared to remove NO at low temperature, where the TiO2 with relatively high specific surface area (184.3 m 2 /g) is used as carrier to support the active component MnOx, and Tm is utilized as promoter to modify the MnOx . The developed Tm–Mn/TiO2 catalyst presents significantly improved selective catalytic reduction (SCR) de-NOx performance at low temperature with NH3 as reducing agent. It is found that after an appropriate content of Tm is introduced, the surface concentration of Mn 4+, the chemical adsorbed oxygen, the chemisorption of NH3 and NO, and the reducibility of the Tm–Mn/TiO2 catalyst are improved, which are helpful to the enhancement of NH3 -SCR de-NOx performance. Moreover, it is discovered that, over Tm–Mn/TiO2 catalyst, an Eley-Rideal (E-R) mechanism occurs in the reaction between adsorbed NH3 species connected by Lewis acid sites and gaseous NO, meanwhile, a Langmuir-Hinshelwood (L-H) mechanism occurs between adsorbed NH3 species and adsorbed NO species, where the E-R mechanism dominates the NH3 -SCR de-NOx process. Graphical abstract: Image 1 Highlights: Tm was used as a dopant to modify Mn/TiO2 catalyst for the SCR de-NOx for the first time. The effects of Tm on the physical and chemical properties of Mn/TiO2 were well disclosed. Tm0.1 Mn/TiO2 exhibited excellent low-temperature de-NOx performance and N2 selectivity. The reaction mechanisms over the Tm0.1 Mn/TiO2 were fully revealed by in-situ DRIFTS.