Performance and kinetics of Pt-CNT catalyst electrodes in a PEM fuel cell

This study investigated the performance of membrane electrode assembly (MEA) fabricated with various loadings of platinum catalyst on carbon nanotubes (CNTs) and sulfonated membrane at constant conditions of duration, temperature and pressure. The fabricated MEA was tested in a single proton exchange membrane (PEM) fuel cell unit using hydrogen and oxygen as fuel and oxidant gases respectively. The results obtained show that the performance of the MEA in the cell improves with increase in loading of the catalyst on the electrodes. The results obtained on kinetics of the fuel cell indicate that the MEA samples fabricated with 30 and 40 wt% Pt catalyst electrodes conform to the Tafel equation whereas the remaining MEA fabricated with 10 and 20 wt% catalyst samples do not obey the Tafel equation due to large values of their overpotential. Hirschenhofer and Tafel equations were used to model the performance of the catalyst electrodes in the cell and the simulated voltage obtained from the former showed better conformity with the experimental voltage than the latter.