Abstract:
To study the effects of conditions of catalysts preparation and to improve CO tolerance of anode catalyst in proton exchange membrane fuel cell (PEMFC). Platinum (Pt) catalyst was highly active but its performance could be deteriorated by the presence of CO, even the minute amount in part per million, in the H[subscript 2]-fuel stream. Pt, binary Pt-alloy and ternary Pt-alloy on carbon-gigantic were chosen as catalysts in this work. The catalysts prepared by impregnation method, were calcined under inert atmosphere at temperature of 350 ํC for 2 hrs. and then were reduced in hydrogen atmosphere at 400 ํC for 2 hrs. Pt-alloy/C catalysts were characterized by temperature program reduction (TPR), chemisorption of hydrogen and CO, and transmission electron microscopy (TEM). The morphology of the samples was characterized using X-ray diffraction (XRD). Membrane and electrode assemblies (MEAs) with metal loading 1 mgcm[superscript 2] were fabricated and performance of CO tolerance being tested in PEM fuel cell operation at 60 ํC with H[subscript 2] fuel containing 20 ppm CO. Ru, Sn, Mo and Pd could enhance H[subscript 2] electro-oxidation activity. It was indicated that CO tolerance of ternary Pt-alloy were higher than that of binary Pt-alloy and Pt catalyst, respectively. Pretreatment of catalysts and ratio of Pt-alloy had a significant effect on the CO tolerance. As a CO tolerant PEM fuel cell anode catalysts, PtRu-MO/C and PtRu-Sn/C in atomic ratio of 1:1:0.22, attain improved performance compared to Pt/C, binary Pt-alloy/C and ternary Pt-alloy/C with the ratio chosen in this work