Particle size effect in nanoscale Pt3Co/C electrocatalysts for low-temperature fuel cells

Pt 3 Co/C electrocatalysts produced by the wet synthesis method out of water-ethylene glycol solu- tions of Pt and Co precursors were investigated by X-ray diffraction in conjunction with electrochemical mea- surements. It was shown that varying the binary solvent composition is an effective way to regulate the nano- particle and grain size distribution. It was found that the unit cell parameter of the Pt 3 Co/C electrocatalysts decreases nonlinearly as the particle sizes dwindle. The activity of the made-up Pt 3 Co/C catalysts for the ORR in H 2 SO 4 solution enhances as the particle size, unit cell parameter, and dispersion of the grain size distribution decrease. All the samples studied show higher catalytic activities than the commercial Pt/C materials.