The Use of Fluorocarbon Surfactants to Improve the Manufacture of PEM Fuel Cell Electrodes

Fluorocarbon surfactants are used to improve surface wetting during the screen printing of carbon black inks onto PEM fuel cell electrodes. The fluorosurfactants were tested in inks that comprised a Nafion® ionomer solution with platinum-loaded carbon black. Four commercially available fluorosurfactants (Zonyl FSO, Zonyl 1033D, Forafac 1098 and Novec FC 4430) were screened and assessed for electrochemical activity (via cyclic voltammetry), leaching and the ability to form ink layers. Good wetting characteristics were observed and the inks showed a similar specific electrochemical active area (200-430 cm2 mg-1 Pt) to a standard reference ink (370 cm2 mg-1 Pt), indicating that the surfactants did not adversely adsorb on the platinum catalyst surface or block the adsorption/desorption of hydrogen. Additionally, the fluorosurfactants in the cured inks were shown to be electrochemically inactive in the potential region relevant to fuel cell operation.