Methanol Oxidation in Alkaline Medium Using PtIn/C Electrocatalysts

Author(s)

Santos, M. C. L. ; Ottoni, C. A. ; de Souza, R. F. B. ; da Silva, S. G. ; Assumpcao, M. H. M. T. ; Spinace, E. V. ; Neto, A. O.

• Document type: Journal article
• Source: ELECTROCATALYSIS; v. 7, n. 6, p. 445-450, NOV 2016.
• Web of Science Citations: 4

Abstract

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. (AU)

• FAPESP's process: 14/09087-4 - Studies on the use of bioethanol in proton exchange membrane and solid oxide fuel cells
• Grantee: Marcelo Linardi
• Support Opportunities: Research Projects - Thematic Grants