Structure Formation and Characterization of PEMFC Catalyst Layers Blended with Multi-walled Carbon Nanotubes

摘要

Different kinds of sub-micron structured carbon, which are carbon black and multi-walled carbon nanotubes (MWCNTs), were blended in catalyst ink to fabricate catalyst layers which differ in pore structure. Carbon black is used as catalyst support in the conventional catalyst layers and the porous structure strongly depends on its aggregate structure. MWCNTs have completely different structure with the carbon black in sub-micron scale. Therefore, two kinds of MWCNTs were blended with the platinum-supported carbon in the catalyst ink and the effects on the structure were investigated. The catalyst layer which contains MWCNT showed lower porosity, fewer micro-cracks and large pores than the conventional catalyst layer which was blended with carbon black. These characteristic porous structure affected cell performance and showed large voltage drop at high current density in its polarization curve.