Halogen exchange reactions for CFC alternatives. The behaviour of fluorine-18 labelled hydrogen fluoride towards prefluorinated chromia containing nickel( II) or zinc( II)

被引:22
作者
Bonniface, DW
Fryer, JR
Landon, P
Scott, JD
Scott, WDS
Watson, MJ
Webb, G [1 ]
Winfield, JM
机构
[1] ICI Klea, Res & Technol Dept, Runcorn WA7 4QD, Cheshire, England
[2] Univ Glasgow, Dept Chem, Glasgow G12 8QQ, Lanark, Scotland
关键词
D O I
10.1039/a808021f
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
Highly active catalysts are required for the conversion of CF3CH2Cl to the CFC-alternative refrigerant, CF3CH2F, by HF vapour under heterogeneous conditions. Chromia impregnated with a very low level of zinc(II) is a superior catalyst precursor to chromia alone. The behaviour of prefluorinated chromia and prefluorinated chromia containing zinc(II) or nickel(II) towards fluorine-18 labelled HF indicates that two types of labile surface fluoride are present, only one of which is catalytically active. Proposals are made to account for the role of Zn-II and Ni-II.
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页码:9 / 11
页数:3
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[11]   Isomerization reaction of 1,1,2,2-tetrafluoroethane on chromia - A study of the active sites on the surface [J].
Niedersen, KU ;
Schreier, E ;
Kemnitz, E .
JOURNAL OF CATALYSIS, 1997, 167 (01) :210-214