The electro-oxidation of isotopically labeled glycerol on platinum: New information on C–C bond cleavage and CO2 production

In this work we investigate the electro-oxidation of glycerol reaction on polycrystalline platinum in acidic media. By using in situ FTIR and isotopically labeled glycerol (13CH2OH–12CHOH–13CH2OH) we demonstrate the co-existence of 13CO2 and 12CO2 as products of electro-oxidation. Results indicate that glycerol completely dissociates on Pt surfaces and that both groups contribute to the production of CO2. Moreover, terminal 13CH2OH groups are easier to electro-oxidize than the central group, which is interpreted in terms of a more favorable position of –13CH2OH groups to react with Pt–OHad species.

► Electrocatalysis of isotopically labeled glycerol on Pt. ► Two independent pathways of CO2 production are revealed by FTIR. ► the first one occurs at low potentials by the oxidation of terminal 13CH2OH groups. ► –12CHOH– groups are more difficult to oxidize. ► Results are interpreted in terms of a steric effect provoked by the terminal groups.