One-pot synthesis of CrαMnβCeTiOx mixed oxides as NH3-SCR catalysts with enhanced low-temperature catalytic activity and sulfur resistance. (6th April 2022)

• Record Type: Journal Article
• Authors: Liu, Wuyuan; Gao, Zihan; Sun, Ming; Gao, Jiajian; Wang, Lifeng; Zhao, Xiangyun; Yang, Runnong; Yu, Lin
• Is Part Of: Chemical engineering science. Volume 251(2022)
• Publication Date: 2022-04-06
• Subjects: NH3-SCR -- SO2 -- Synergetic effect -- Low-temperature -- Fast SCR; Chemical engineering -- Periodicals; Génie chimique -- Périodiques; Chemical engineering; Periodicals; Electronic journals; 660
• DOI: 10.1016/j.ces.2022.117450
• Languages: English
• ISSNs: 0009-2509

Abstract

Highlights: Cr and Mn improved the low-temperature catalytic activity and SO2 resistance. Cr and Mn doping improved the rate of the catalytic reaction. The reaction followed the Eley–Rideal and Langmuir–Hinshelwood mechanisms. The catalyst significantly inhibited the accumulation of bisulfate or sulfate. Abstract: A series of Crα Mnβ CeTiOx catalysts were prepared using one-pot precipitation method and evaluated for the selective catalytic reduction (SCR) of NO with ammonia. Among the catalysts prepared, the Cr0.006 Mn0.05 CeTiOx catalyst exhibited the highest low-temperature activity and widest activity window (＞90% NO conversion at 160–425 °C) as well as outstanding sulfur resistance. The catalysts were characterized using XRD, NH3 /NO/SO2 + O2 -TPD, XPS, in situ DRIFT, and so on. The amorphous Cr0.006 Mn0.05 CeTiOx catalyst had a larger specific surface area, high ammonia adsorption and strong acidity, resulting in an improved catalytic activity. A high ratio of surface adsorption oxygen and Ce 3+ promoted the formation of NO2, a key intermediate gas in the fast SCR reaction. Furthermore, in situ DRIFT showed that the SCR reaction followed the Eley Rideal and Langmuir Hinshelwood mechanisms. Moreover, the synergetic effect of Cr and Mn inhibited the accumulation of hydrogen sulfate or sulfate considerably.