Electrochemical reduction of nafion 117

Abstract

The reduction of Nafion 117 in the K + cycle with lithium amalgam proceeds by an electrochemical corrosion mechanism analogously to the reduction of poly(tetraflouroethylene). The thickness of the reacted polymer layer is proportional to the square root of the time: d=kt frsol:1/2; the rate constant K=0.92±0.006μ m h − sol:1 2 at 100°C. The reduction product has a mixed cationic—electronic conductivity and is a mixture of LiF and chemically modified elemental carbon. The rate of electrochemical reduction of Nafion 117 is limited by the Li + cation conductivity of the reduction product. The elemental carbon formed, which contains bound sulphonic groups originating from the Nafion, can be isolated by extracting the primary reduction product with water.