Abstract: PtRu nanoparticles were loaded on carbon aerogels (CAs) by the ethylene glycol reduction method. TEM observations show that the PtRu particles are uniformly dispersed on CAs with a particle size of 3nm. Both cyclic voltammetry and constant potential show that the catalyst on CA with large pores has a high activity for methanol oxidation. The onset potential for methanol oxidation in cyclic voltammetry is independent of the kind of CA. The differences of catalyst activity are mainly attributed to the different mass transportation properties of the CAs. The methanol diffuses faster through larger pores, which makes it easy for methanol to arrive at the PtRu particles and improve the utilization rate of noble metals.