Development of nanophase CeO₂-Pt/C cathode catalyst for direct methanol fuel cell

Incorporation of nanophase ceria (CeO₂) into the cathode catalyst Pt/C increased the local oxygen concentration in an air atmosphere, leading to enhanced single-cell performance of direct methanol fuel cell (DMFC). Ceria doped catalysts were effective at low oxygen partial pressure (≤0.6 atm) conditions and 1 wt.% CeO₂ doped Pt/C exhibited the highest performance. The effect of ceria was more prominent with air as the cathode reactant and the ceria acted as a mere impurity in a pure oxygen atmosphere, decreasing the DMFC performance. Impedance spectra showed a decrease in polarization resistance with the ceria addition to the cathode catalyst in low-potential regions confirming the facile mass transfer of the reactant oxygen molecules to catalytic sites. Transmission electron microscopy (TEM) pictures showed a uniform distribution of CeO₂ around platinum sites.