Electrochemical Characterization of PtRu Nanoparticles Supported on Mesoporous Carbon for Methanol Electrooxidation

Nanoparticles of PtRu supported on mesoporous carbon were obtained by the impregnation and reduction method with NaBH4. The high-surface-area mesoporous carbon was obtained by carbonization of a resorcinol-formaldehyde polymer with a cationic polyelectrolyte as a soft template. Surface characterization performed by transmission electron microscopy and powder X-ray diffraction showed a homogeneous distribution and high dispersion of metal particles. The PtRu catalyst shows an electrochemical active surface area, determined by CO stripping, 45% higher than PtRu catalyst synthesized by the same method on Vulcan. This translated in a 25% increase in the methanol oxidation current as well as a lower poisoning rate and higher turnover frequency, as was assessed by cyclic voltammetry and chronoamperometry. Differential electrochemical mass spectroscopy indicated an 8% higher conversion efficiency of methanol to CO2, demonstrating the benefits of using a mesoporous carbon as catalyst support.