Some insights on the electro-oxidation of glycerol on platinum nanoparticles supported on carbon multi-walled nanotubes: An in situ FTIR analysis

MARTINS C. A.; FERNÁNDEZ P. S.; MARTINS M. E.; CÂMARA G. A.

San Pablo

Congreso; Electrochemistry towards high performance systems: the use of nanomaterials; 2011

Instituto de Química, Universidade de São Paulo, São Paulo, Brasil

We investigate the glycerol electro-oxidation reaction on carbon platinum nanoparticles supported on carbon multi-walled carbon nanotubes (MWCNT) obtained by reduction with ethyleneglycol using PVP. The voltammetric results suggest a complex electro-oxidation kinetics and the existence of several reaction pathways. We followed this reaction by FTIR in situ. The COad band starts grows up to 0.7 V, which coincides well with the potential where CO2 begins to be produced. Afterwards the COad band signal decays abruptly. This behavior indicates that COad is the intermediate of CO2. After that, COad signal falls (around 1.1 V) and the production of CO2 is accelerated. At these potentials, the surface of the electrode is mainly covered by OH species and the CO coverage is negligible. This behavior indicates that the reaction step which depends on the CO coverage can be discarded at these potentials as determining step of the process. Moreover, the CO is not the only intermediate for the production of CO2. Accordingly, the formation of CO2 can result from a pathway which produces carbonyl compounds as intermediate.