Proton transfer in Nafion membrane by quantum chemistry calculation

Abstract

We estimated the energy barriers of proton transfers in the systems of (CF 3SO 3/H/SO 3CF 3) - and (CF 3SO 3/H/H 2O/SO 3CF 3) - as models of a water-swollen Nafion membrane by an ab initio density functional quantum calculation method with consideration of the hydration effect. As a result, the proton transfer between the SO 3- sites, which is accompanied by one water molecule, was found to be one of the proton-transfer mechanisms in the water-swollen Nafion membrane; that is, the surface diffusion mechanism was found to be important for the proton transfer in that membrane. © 2004 Wiley Periodicals, Inc.