Abstract:
PEM (Proton Exchange Membrane) fuel cell is a clean and efficient energy conversion system using electrochemical reaction of hydrogen and oxygen to generate electricity. However, conventional catalyst loading methods, such as hand-painting and air-brushing, bring about a significant material loss and non-uniform catalyst layer, which pose problems in capital cost and platinum utilization. This research studied the preparation of catalyst coated-membrane by direct printing of catalyst onto Nafion membrane, using a piezoelectric inkjet printer. The small droplet size of 10 pL and programmable area printing help produce a well-defined shape of the catalyst layer without the need for a mask. The current density of membrane electrode assembly prepared by inkjet printing of Pt/C catalyst, with the loading of 0.15 mg/cm2, on membrane was found to be 476 mA/cm2 at 0.6 V. Moreover, this research was carried out to develop the CO-tolerant composite catalyst-coated membrane in comparison with that prepared by single catalyst layer. It was found that MEA which has PtRu/C layer on anode side had the best CO-tolerance. This research also scaled up the catalyst-coated membrane from 5 cm2 to 25 cm2 by inkjet printing. The scaled up catalyst-coated membrane showed a lower current density of only 11 percent at 0.6 V.