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

Authors
Bonniface, DW Fryer, JR Landon, P Scott, JD Scott, WDS Watson, MJ Webb, G Winfield, JM
Citation
Dw. Bonniface et al., Halogen exchange reactions for CFC alternatives. The behaviour of fluorine-18 labelled hydrogen fluoride towards prefluorinated chromia containing nickel( II) or zinc( II), GREEN CHEM, 1(1), 1999, pp. 9-11
Citations number
11
Categorie Soggetti
Chemistry
Journal title
GREEN CHEMISTRY
ISSN journal
14639262 → ACNP
Volume
1
Issue
1
Year of publication
1999
Pages
9 - 11
Database
ISI
SICI code
1463-9262(199902)1:1<9:HERFCA>2.0.ZU;2-0
Abstract
Highly active catalysts are required for the conversion of CF3CH2Cl to the CFC-alternative refrigerant, CF3CH2F, by HF vapour under heterogeneous cond itions. Chromia impregnated with a very low level of zinc(II) is a superior catalyst precursor to chromia alone. The behaviour of prefluorinated chrom ia and prefluorinated chromia containing zinc(II) or nickel(II) towards flu orine-18 labelled HF indicates that two types of labile surface fluoride ar e present, only one of which is catalytically active. Proposals are made to account for the role of Zn-II and Ni-II.