Bernd Cermenek

The Effect of Platinum Electrocatalyst on Membrane Degradation in Polymer Electrolyte Fuel Cells.

Membrane degradation is a severe factor limiting the lifetime of polymer electrolyte fuel cells. Therefore, obtaining a deeper knowledge is fundamental in order to establish fuel cells as competitive product. A segmented single cell was operated under open circuit voltage with alternating relative humidity. The influence of the catalyst layer on membrane degradation was evaluated by measuring a membrane without electrodes and a membrane-electrode-assembly under identical conditions. After 100 h of accelerated stress testing the proton conductivity of membrane samples near the anode and cathode was investigated by means of ex situ electrochemical impedance spectroscopy. The membrane sample near the cathode inlet exhibited twofold lower membrane resistance and a resulting twofold higher proton conductivity than the membrane sample near the anode inlet. The results from the fluoride ion analysis have shown that the presence of platinum reduces the fluoride emission rate; which supports conclusions drawn from the literature.

Alkaline Direct Ethanol Fuel Cell

Abstract Alkaline direct ethanol fuel cell (ADEFC) is a promising environment-friendly energy converter for the production of clean and efficient power. This chapter describes the electrode reaction mechanisms of ADEFC and the transport and degradation mechanisms in anion exchange membranes and the challenges of catalyst and membrane research and development of ADEFC. The understanding of reaction mechanisms in membranes and catalysts is the prerequisite to improve the performance and to develop new materials for ADEFC for future use in portable and small stationary applications.