Effect of Ptm (Bi, Mo) Sub < 10 Nm Nanoparticles Supported on N-Doped Carbon on the Crude Glycerol Electro-Oxidation Reaction

In this work, Pt, PtMo and PtBi materials with 1:1 atomic ratios were synthesized by a typical aqueous reduction method and used as electrocatalysts for glycerol and crude glycerol electro-oxidation reactions. Additionally, these nanomaterials were supported on N-doped carbon obtained from the carbonization of hemispherical polyaniline nanoparticles obtained by chemical methods. Crude glycerol was obtained from the Biodiesel production through the transesterification reaction of vegetal oils from a rotisserie and from a seafood restaurant located in Cortazar, Mexico. Physicochemical characterization indicated that the N-doped carbon support displayed a BET surface area of 483.8 m2 g-1, which is twice the reported value for benchmarked Vulcan carbon XC-72R (~230 m2 g-1). High-resolution transmission electron micrographs (HR-TEM), revealed that all materials presented particle sizes below 10 nm, while the particles displayed good dispersion on the support. Electrochemical evaluation indicated that the use of N-doped carbon as support on Pt nanoparticles achieved an onset potential (Eonset) of -0.48 V vs. NHE, which is only 210 mV more positive to the standard potential (-0.69 V vs. SHE). The use of Mo as co-metal did not influence the Eonset, but it increased 2.6 times the current density in comparison with Pt/N-doped C. On the other hand, the use of Bi as a p-block co-metal improved the Eonset achieving -0.54 V vs. NHE, while the resulting current density was 4.13 times higher to that obtained for Pt/N-doped C.