National Research Council of Canada. Energy, Mining and Environment
Solid state electrochemical techniques have provided insight into the effect of relative humidity on oxygen mass transport properties in Nafion® 117. Specifically, subsequent potential step coulometric measurements taken over a period of time have shown that the act of measurement affects the catalyst-membrane interface. It is postulated that the formation of product water at the interface leads to interactions with the Nafion® 117 surface and results in local domain changes. This effect has been shown to be reversible provided there is adequate rest time between measurements to allow for water diffusion from the interface.