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A New Insight into Active Cu 2+ Species Properties in One‐Pot Synthesized Cu‐SSZ‐13 Catalysts for NO x Reduction by NH 3
Author(s) -
Chen Jiawei,
Zhao Ru,
Zhou Renxian
Publication year - 2018
Publication title -
chemcatchem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.497
H-Index - 106
eISSN - 1867-3899
pISSN - 1867-3880
DOI - 10.1002/cctc.201801234
Subject(s) - catalysis , space velocity , copper , selective catalytic reduction , rietveld refinement , chemistry , hexagonal prism , crystallography , chabazite , redox , inorganic chemistry , hexagonal crystal system , crystal structure , zeolite , selectivity , organic chemistry
The Cu‐SSZ‐13 catalysts with different copper content are prepared by one‐pot method and changing the mole ratio of Cu‐tetraethylenepentamine/Al 2 O 3 . Cu‐SSZ‐13 catalyst with 3.25 wt.% Cu exhibits excellent catalytic activity (operation temperature window of 145–490 °C), adaptability to high GHSV (gas hourly space velocity) and hydrothermal stability in NH 3 ‐SCR reaction. The results of XRD Rietveld refinement coupled with H 2 ‐TPR and EPR show that three active Cu 2+ species (Cu1, Cu2 and Cu3) locate in various sites in the CHA (chabazite) structure and play different action in NH 3 ‐SCR reaction. Cu1 species situated close to an eight‐membered‐ring play a crucial role in the low temperature activity for its optimum reduction ability. While Cu3 species located in the center of the hexagonal prism are the most stable and its content basically remains unchanged after SO 2 pretreatment, which contributes to the excellent SO 2 resistance.