Mariano M. Bruno

High-Activity Mesoporous Pt/Ru Catalysts for Methanol Oxidation

High activity mesoporous Pt/Ru catalysts with 2D-hexagonal structure were synthesized using a triblock poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) copolymer (Pluronic F127) template. The normalized mass activities for the methanol oxidation reaction (MOR) of the Pt/Ru catalysts with a regular array of pores is higher than those reported for nanoparticulated Pt/Ru catalysts. Different kinetic parameters, as Tafel slope and activation energy, were obtained for the MOR on the mesoporous catalysts. Results indicated that catalysts performance depends on pore size. Mass activities and the CO2 conversion efficiency for large pore size mesoporous catalysts (10 nm) are greater than those reported for smaller pore size mesoporous catalysts with similar composition. The effect of pore size on catalysts performance is related to the greater accessibility of methanol to the active areas inside large pores. Consequently, the overall residence time of methanol increases as compared with mesoporous catalyst with small pores.

Porous carbon–carbon composite replicated from a natural fibre

Highly porous carbon composites, suitable to be used as electrodes in electrochemical double layer capacitors, could be produced by pyrolysis of resorcinol-formaldehyde resins impregnated onto a natural fibre material (celullosic fabric), without additional template agents or special drying of the polymer gels.

Synthetic Porous Carbon as Support of Platinum Nanoparticles for Fuel Cell Electrodes

Porous vitreous carbon can be produced by pyrolysis of resorcinol-formaldehyde porous resin. Using surfactants as stabilizers, it is possible to dry the porous resin in air without pore collapse. Having a large surface area (>500 m2/g) and high electronic conductivity makes the materials suitable as support of electrocatalyst nanoparticles. Pt nanoparticles were prepared by a microemulsion method and impregnated into the carbon pores by adsorption from its suspension. The presence of the Pt nanoparticles is easily detected by the electrochemical reduction of proton and the evolution of H2, detected by DEMS. The cyclic voltammogram of the modified electrode in presence of CO does not show current due to CO oxidation to CO2. On the other hand, the differential electrochemical mass spectroscopy (DEMS) signal clearly shows CO2 production. Methanol can be electroxidized on the electrode containing Pt nanoparticles supported on porous carbon.

Carbon Materials for Fuel Cells

Carbon materials are fundamental for the manufacturing of fuel cells. Several fuel cell components are made entirely of carbon in a graphitic form. In the present chapter, an overview of the different fuel cell carbon components and the materials used in their preparation will be presented. Novel approaches in the synthetic method, in order to impart desired properties, and in the manufacturing of the components will be shown. Also, relevant results on the latest research conducted will be discussed.