In this study, a fibrous carbon material, Marimo nano carbon (MNC), was investigated as a catalyst support material for a direct methanol fuel cell. MNC comprises diamond particles in its core and carbon nanofilaments that radiate outward from the diamond core. The MNC-supported Pt catalyst (Pt/MNC) exhibited better performance than the conventional catalyst support material (i.e., carbon black). Higher Pt dispersion was observed on MNC compared to carbon black, with decreased Pt loading. Pt/MNC exhibited high electrochemical activity. [GRAPHICS]