Generation of carbon dioxide from glycerol: Evidences of massive production on polycrystalline platinum

In this work we investigate the glycerol electrooxidation reaction on polycrystalline platinum in acid media. Cyclic voltammetry shows the existence of multiple oxidation peaks, which are related with a complex electrooxidation mechanism. We follow the voltammetric response of Pt in the presence of glycerol by using FTIR in situ. Results show that during glycerol electrooxidation massive amounts of CO2 are produced. The production of CO2 begins at low potentials and depends on the previous formation of adsorbed CO. This pathway is accelerated at high potentials and seems to be the main responsible for the rising of the currents observed in the cyclic voltammogram for potentials up to 1.0 V. Moreover, there is a parallel pathway involving the production of a carboxylic acid (probably glyceric acid), but the relative magnitudes of CO2 bands and acid bands makes clear that the production of CO2 is the dominant feature of the spectra, suggesting that glycerol can be a suitable candidate for use in direct alcohol fuel cells.

► Glycerol electrooxidation produces massive amounts of CO2 on Pt surfaces.
► The production of CO2 seems to be the main responsible for the rising of the currents observed at high potentials.
► Other bands emerging from FTIR spectra are related with the formation of a carboxylic acid, which is probably glyceric acid.