Direct Ethanol Fuel Cells: The influence of structural and electronic effects on Pt-Sn/C electrocatalysts

Autor(es)

Colmati, Flavio ^[1] ; Magalhaes, Monah M. ^{[1, 2]} ; Sousa Jr, Ruy ; Ciapina, Eduardo G. ^[3] ; Gonzalez, Ernesto R. ^[4]

Afiliação do(s) autor(es)

^[1] Univ Fed Goias, Inst Quim, Ave Esperanca S-N, BR-74690900 Goiania, Go - Brazil

^[2] Pontificia Univ Catolica Goias, Ave Univ 1440, BR-74605010 Goiania, Go - Brazil

^[3] Sao Paulo State Univ Unesp, Av Dr Ariberto Pereira Cunha 333, BR-12516410 Guaratingueta, SP - Brazil

^[4] Univ Sao Paulo, Inst Quim Sao Carlos, CP 780, BR-13560970 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: INTERNATIONAL JOURNAL OF HYDROGEN ENERGY; v. 44, n. 54, p. 28812-28820, NOV 5 2019.
• Citações Web of Science: 0

Resumo

Carbon-supported platinum-tin electrocatalysts (Pt-Sn/C) are known to be the most efficient fuel cell anode material to oxidize ethanol in the so-called Direct Ethanol Fuel Cells (DEFC). However, the platinum-tin binary system presents distinct phases depending on the amount of Sn (i.e., the Pt:Sn ratio) and on the thermal annealing temperatures, as well as the presence of oxides (e.g. SnO2) whose influence on the performance of DEFCs is not well understood. In this work, Pt-Sn catalysts presenting distinct Pt:Sn ratios were prepared, characterized and tested in a single DEFC. The combined results from DEFC tests and structural characterization techniques showed that increasing the amount of Sn dissolved into the Pt structure enhances DEFC performance but also that Sn content alone does not explain the overall behavior. Microstructural effects on the DEFC response was further investigated by performing a comprehensive study using high intensity X-ray Diffraction and in situ-X-Ray Absorption Spectroscopy provided by synchrotron light on Pt3Sn1/C samples subjected to thermal treatments in a reducing H-2 atmosphere at temperatures of 100, 200, 300, 400, and 500 degrees C. The results showed that best DEFC performance depends on a balance between the amount of Sn dissolved in Pt, the formation of a new phase (PtSn) and also on the presence of tin oxides, yielding a material with an optimized modified 5d-band electronic structure, which was obtained with a thermal treatment at 200 degrees C. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 09/07629-6 - Eletrocatálise IV: aspectos fundamentais e aplicados dos processos eletrocatalíticos, bio-eletrocatálise e instabilidades cinéticas
• Beneficiário: Edson Antonio Ticianelli
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOEN - Temático