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In situ Raman spectroscopy studies on chromium oxide catalyst in an anhydrous hydrogen fluoride atmosphere
Author(s) -
Xing Liqiong,
Bi Qingyuan,
Wang Yuejuan,
Guo Ming,
Lu Jiqing,
Luo Mengfei
Publication year - 2011
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.2811
Subject(s) - anhydrous , hydrogen fluoride , raman spectroscopy , chromium , chemistry , catalysis , in situ , atmosphere (unit) , fluoride , hydrogen , reducing atmosphere , inorganic chemistry , oxide , oxidation state , spectroscopy , nuclear chemistry , organic chemistry , physics , quantum mechanics , optics , thermodynamics
Changes of different chromium oxide species [Cr(VI), Cr(V) and Cr(III)] were investigated using in situ Raman spectroscopy in an anhydrous hydrogen fluoride (AHF) atmosphere. It was found that the Cr(VI) (CrO 3 ) and Cr(V) (YCrO 4 ) species were easy to fluorinate, and generated CrO 2 F 2 or/and CrOF 3 , while the Cr(III) (Cr 2 O 3 ) species was difficult to fluorinate. Moreover, the CrO 2 F 2 and CrOF 3 species were stable in the AHF atmosphere, but they easily transform into CrO 3 in N 2 atmosphere and further decomposed to Cr 2 O 3 at 400 °C. Moreover, Cl/F exchange reaction of CF 3 CH 2 Cl to CF 3 CH 2 F over these Cr species indicated that the high‐oxidation‐state CrO x F y (CrO 2 F 2 and CrOF 3 ) species exhibited much higher reactivities than Cr 2 O 3 , suggesting that these species (CrO 2 F 2 and CrOF 3 ) may be the active phases of the reaction. Copyright © 2010 John Wiley & Sons, Ltd.