SURFACE-CHEMISTRY OF PERFLUOROETHER - A STUDY OF THE REACTION-MECHANISM OF (C2F5)(2)O WITH AN AL2O3 SURFACE BY FTIR SPECTROSCOPY

The decomposition of perfluorodiethyl ether on alumina has been studie d at 300 and 500 K by transmission infrared spectroscopy using excess ether under high-pressure conditions. It was found in this study that the reaction products include trifluoro-, difluoro-, and monofluoroace tate, fluoroformate, alkyl acetate, and alkyl formate. The initial for mation of trifluoroacetate probably results from a nucleophilic attack at the a-carbon of the ether by a surface oxygen anion. Subsequently, fluorine atoms, abstracted by coordinately unsaturated (cus) aluminum atoms, are replaced by hydrogen atoms donated by isolated surface hyd roxyls. There is also evidence that fluoroalkene and fluoroalkyne resu lted from the decomposition of initial surface adsorbates.