Supported high surface AlF3: a very strong solid Lewis acid for catalytic applications

Abstract

A series of HS-AlF₃/Al₂O₃ with different HS-AlF₃ loading was prepared by impregnation method using aluminium isopropylate in isopropyl alcohol as a solvent and non-aqueous HF solution. Post-fluorination of the supported AlF₃ precursor was carried out under moderate conditions with CHClF₂ or HF. The catalytic activity of the supported HS-AlF₃ was assessed by study of the CHClF₂ dismutation and CBrF₂CBrFCF₃isomerization reactions. All the supported HS-AlF₃ samples were found to be effective for CHClF₂ dismutation, whereas HS-AlF₃/γ-Al₂O₃^a exhibited superior activity, which was about 10–30 times higher than that of HS-AlF₃/α-Al₂O₃, in terms of isomerization activity.