Synthesis of CrOx/C catalysts for low temperature NH3-SCR with enhanced regeneration ability in the presence of SO2. Issue 7 (22nd January 2018)

• Record Type: Journal Article
• Authors: Yu, Shuohan; Xu, Sheng; Sun, Bowen; Lu, Yiyang; Li, Lulu; Zou, Weixin; Wang, Peng; Gao, Fei; Tang, Changjin; Dong, Lin
• Is Part Of: RSC advances. Volume 8:Issue 7(2018)
• Page Start: 3858
• Page End: 3868
• Publication Date: 2018-01-22
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c7ra09680a
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Novel CrO x @C catalyst with both remarkable NH3 -SCR activity and satisfactory regeneration ability in the presence of SO2 . Abstract : Chromium oxide nano-particles with an average diameter of 3 nm covered by amorphous carbon (CrO x /C) were successfully synthesized. The synthesized CrO x /C materials were used for the selective catalytic reduction of NO x by NH3 (NH3 -SCR), which shows superb NH3 -SCR activity and in particular, satisfactory regeneration ability in the presence of SO2 compared with Mn-based catalysts. The as-prepared catalysts were characterized by XRD, HRTEM, Raman, FTIR, BET, TPD, TPR, XPS and in situ FTIR techniques. The results indicated presence of certain amounts of unstable lattice oxygen exposed on the surface of CrO x nano-particles with an average size of 3 nm in the CrO x /C samples, which led to NO being conveniently oxidized to NO2 . The formed NO2 participated in NH3 -SCR activity, reacting with catalysts via a "fast NH3 -SCR" pathway, which enhanced th NH3 -SCR performance of the CrO x /C catalysts. Furthermore, the stable lattice of the CrO x species made the catalyst immune to the sulfation process, which was inferred to be the cause of its superior regeneration ability in the presence of SO2 . This study provides a simple way to synthesize stable CrO x nano-particles with active oxygen, and sheds light on designing NH3 -SCR catalysts with highly efficient low temperature activity, SO2 tolerance, and regeneration ability.