The decomposition of perfluorodiethyl ether on alumina has been studied 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 monofluoroacetate, fluoroformate, alkyl acetate, and alkyl formate. The initial formation 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 hydroxyls. There is also evidence that fluoroalkene and fluoroalkyne resulted from the decomposition of initial surface adsorbates.