Methanol Oxidation in Alkaline Medium Using PtIn/C Electrocatalysts

• Published in: Electrocatalysis Vol. 7; no. 6; pp. 445 - 450
• Main Authors: Santos, M. C. L., Ottoni, C. A., de Souza, R. F. B., da Silva, S. G., Assumpção, M. H. M. T., Spinacé, E. V., Neto, A. O.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.11.2016; Springer Nature B.V
• Subjects: Catalysis; Chemistry; Chemistry and Materials Science; Electrocatalysts; Electrochemistry; Energy Systems; Methanol; Nanoparticles; Original Research; Particle size; Physical Chemistry; Voltammetry; X-ray diffraction; PtIn electrocatalysts; Methanol oxidation; Alkaline fuel cell
• ISSN: 1868-2529; 1868-5994
• DOI: 10.1007/s12678-016-0324-z

Pt/C and PtIn/C with atomic ratios of 90:10, 70:30, and 50:50 were investigated for methanol electro-oxidation in alkaline media by using cyclic voltammetry (CV), chronoamperometry (CA), and direct methanol alkaline fuel cell (DMAFC). All electrocatalysts were synthesized using sodium borohydride method with 20 wt% of metals loading on carbon. X-ray diffraction (XRD) analysis revealed that bimetallic PtIn had faced centered cubic structure and, also, confirmed alloy formation for PtIn/C nanoparticles. Transmission electron micrographs showed metal nanoparticles with average particle size between 3.0 and 5.0 nm; however, the particle size increases when the In content was increased in PtIn/C. In the CV experiments, the onset potential of methanol electro-oxidation shifted to lower values as the indium content increased. Chronoamperometry experiments and direct methanol alkaline fuel cell suggested PtIn/C (70:30) as the most promising material for methanol electro-oxidation: this result could be explained by the presence of Pt and In in close contact (electronic effect) as the occurrence of oxy-hydroxy interactions. Graphical Abstract Chronoamperometry curves for PtIn/C electrocatalysts at 25 °C.