New insights about the electro-oxidation of glycerol on platinum nanoparticles supported on multi-walled carbon nanotubes

Here we investigate the glycerol electro-oxidation reaction on carbon platinum nanoparticles supported on multi-walled carbon nanotubes (MWCNTs) obtained by reduction with ethylene glycol. The particles obtained show uniform particle diameters with a little size dispersion (2.8 ± 0.2 nm). Cyclic voltammetry shows the existence of multiple oxidation peaks, which are related with different electrooxidation steps. We follow the voltammetric response of Pt/MWCNT in the presence of glycerol by using in situ FTIRS. Results suggest that CO2 is produced by two independent pathways. The first one happens at low potentials and depends on the previous formation of adsorbed CO, while the second one occurs at high potentials and seems to depend on the reaction of glycerol in solution with adsorbed Pt–O. FTIRS results also show products of higher degree of oxidation as the potential increases. Results were interpreted in terms of a growing superficial recovering by Pt–O species with the potential.

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► Pt/MWCNT particles present high homogeneous particle size.
► CO2 seems to be formed by two routes.
► The first one occurs at low potentials and involves the co-adsorption of Pt–O and CO.
► The second one happens at high potentials and is fed by a reaction of glycerol in solution with Pt–O.
► The Pt–O coverage explains the several products of electro-oxidation identified by in situ FTIR.