Boosting the catalytic performance of Fe/Zr catalyst by tungsten addition for selective catalytic reduction of NOx with ammonia. (15th February 2023)

• Record Type: Journal Article
• Authors: Li, Xiaodi; Ren, Shan; Xing, Xiangdong; Liu, Lian; Jiang, Yanhua; Chen, Lin; Li, Jiangling; Yang, Jian; Liu, Qingcai
• Is Part Of: Fuel. Volume 334(2023)Part 1
• Publication Date: 2023-02-15
• Subjects: NH3-SCR -- NOx conversion -- WO3-doping -- Fe/Zr catalyst -- In-situ DRIFTS; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2022.126633
• Languages: English
• ISSNs: 0016-2361

Abstract

Graphical abstract: Doping WO3 with proper amount could increase the concentration of Fe 3+ and chemisorbed oxygen, and enhance the surface acidity and redox ability. The in-situ DRIFTS spectra demonstrated that only the E-R mechanism was followed in the NH3 -SCR reaction on Fe/Zr catalyst, while the NH3 -SCR on Fe/Zr-0.1W catalyst followed both Eley-Rideal and Langmuir-Hinshelwood mechanisms. Highlights: WO3 doped Fe/Zr catalysts were prepared via wet impregnation. The introduction of WO3 enhanced the catalytic performance of Fe/Zr catalyst. WO3 doping promoted the amount of surface acid sites and the adsorption of NH3 . WO3 doping increased the L-H reaction pathway on the surface of Fe/Zr catalyst. Abstract: To clarify the effect of WO3 doping over Fe/Zr catalyst, several Fe/Zr- x W catalysts were prepared via conventional wet impregnation method, and the selective catalytic reduction (SCR) performance was studied. The Fe/Zr-0.1 W catalyst showed the highest catalytic activity and achieved nearly 100 % in a wide operating temperature window of 300–500 °C, and the N2 selectivity exceeded 90 % over the entire temperature range under a high hour space velocity of 90, 000 h −1 . In addition, Fe/Zr-0.1 W catalyst also exhibited superior resistance to SO2 compared to Fe/Zr catalyst without WO3 introduction. Further characterization results indicated that the Fe/Zr-0.1 W catalyst possessed larger BET specific surface area, better dispersion of active component, higher concentration of Fe 3+ and more surface chemisorbed oxygen species, which might be the predominant factors for its superior catalytic performance. More importantly, WO3 doping improved the redox capacity and surface acidity, thus promoting the redox circle and enhancing the adsorption ability of NH3 . According to the transient in-situ DRIFTS experiment results, the doping of WO3 increased the L-H reaction pathway on the surface of Fe/Zr catalyst during the NH3 -SCR reaction. The present work could provide a new way for developing a high-performance non-vanadium SCR catalyst in practical application.