Abstract: To gain insight into the effect of increasing porosity on methanol electro-oxidation, La2O3 particles prepared throughmolten salt method were introduced into a Pt/carbon nanotubes (CNTs) catalyst layer and then dissolved in HClO4, which increased the porosity in the Pt/CNTs catalyst layer. The existence of the as-formed pore structures was confirmed by scanning electronic microscopy (SEM). Cyclic voltammetry (CV) and chronoamperometry methods were used to investigate the effect of increasing porosity, which showed that the methanol electro-oxidizing current was enhanced by 57%. The reason for this result is ascribed to improved methanol access to the Pt surface in the porous catalyst layer. The results indicate that the fabrication of pores in catalyst layer by dissolving away premixed La2O3 particles is an effective method to promote catalyst layer performance.

Key words: Methanol electro-oxidation, Catalyst layer, Pore-forming agent, La2O3 particles, Direct methanol fuel cell