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.