Effect of Co in the efficiency of the methanol electrooxidation reaction on carbon supported Pt

• Published in: Journal of power sources Vol. 195; no. 24; pp. 7959 - 7967
• Main Authors: Hernández-Fernández, P., Montiel, M., Ocón, P., Fierro, J.L.G., Wang, H., Abruña, H.D., Rojas, S.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.12.2010; Elsevier
• Subjects: Alloying; Alloying elements; Anodizing; Carbon nanotubes; Catalysis; Catalysts; Catalysts: preparations and properties; Chemistry; CO 2 efficiency; DEMS; Exact sciences and technology; General and physical chemistry; Methanol oxidation reaction; Methyl alcohol; Oxidation; Platinum; PtCo nanoparticles; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; DEMS; Carbon nanotubes; Methanol oxidation reaction; CO 2 efficiency; PtCo nanoparticles; Performance evaluation; efficiency; Nanoparticle; Carbon dioxide; CO; Supported catalyst; Oxidation; Electrochemical reaction; Methanol
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2010.06.009

The effect of Co addition to carbon nanotubes supported Pt in the methanol oxidation reaction has been investigated by means of differential electrochemical mass spectrometry (DEMS). It has been observed that the CO 2 efficiency increases in carbon nanotubes supported PtCo compared to its homologous Pt catalysts, especially at potentials lower than 0.55 V. Despite of this, the Faradaic current reached by the bimetallic catalysts in the methanol electrooxidation was lower than those recorded on the monometallic samples. This is because Co addition difficult finding enough Pt vicinal sites for methanol dehydrogenation. On the other hand, it has been found that alloying Pt with Co, shifts down the d-band center of the larger element, so the strength of the interaction with adsorbates decreases. Consequently, it will be easier to oxidize CO ad on the bimetallic surface. Furthermore, the necessary –OH ad species for the CO ad oxidation to CO 2 will be provided by the CNTs themselves.