Electrochem. perfluorination of octanesulfonyl fluoride [40630-63-5] and octanoyl fluoride [592-94-9] to their fluoro compds. was studied over a wide range of exptl. conditions. Significant improvement of the reported yield of perfluoro-product was achieved with electrolysis at high potential. The results are explained in terms of a model involving simultaneous adsorption of the reactant and of F on a NiF2 surface. [on SciFinder (R)]