Pd electroless plated Nafion® membrane for high concentration DMFCs

A Pd layer was deposited on Nafion® membrane by electroless plating in order to reduce methanol crossover. The composite membrane was characterized by using the following techniques of X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray spectrometer (EDXS) and transmission electron microscopy (TEM). Methanol crossover was determined by the electrochemical method. The experimental results indicated that Pd film was successfully deposited onto the Nafion® membrane. The methanol permeability was effectively suppressed by the Pd layer, with methanol-related current decreasing from 64 mA/cm2 (Jlim) to 57 mA/cm2 for 1 M methanol and from 267 mA/cm2 to 170 mA/cm2 for 5 M methanol, respectively. Furthermore, by employing the novel Pd-Nafion® composite electrolyte, the performance of single fuel cell was obviously improved with a high concentration of methanol such as 5 M, indicating that depositing Pd layer onto the Nafion® membrane is an effective method to suppress the methanol crossover.