Pt-Sn Catalysts for Ethanol Oxidation in Fuel Cell Systems: Effect of reducing choice

Pt-Sn Catalysts for Ethanol Oxidation in Fuel Cell Systems: Effect of reducing choice

LÓPEZ-SUÁREZ, F. E.; CARVALHO-FILHO, C. T.; BUENO-LÓPEZ, A.; EGUILUZ, K. I. B.; SALAZAR-BANDA, G. R.

Artigo:

The Pt-Sn/C electrocatalysts performance greatly depends on preparation procedures and Pt:Sn atomic ratios. Here, we synthesized a series of Pt-Sn/C nanoparticle catalyst with a 20% (w/w) metal load (Pt + Sn) on carbon black with a nominal Pt:Sn atomic ratio of 3:1, NaBH4 (A) using and formic acid (B) as reducing agents aiming to study the effect of preparation method on chemical–physical properties of electrocatalyst. The onset potential of ethanol electrooxidation over Pt-Sn/C catalyst was shifted by about 0.03 V negatively in comparison with that over Pt/C catalysts. At lower potential than 0.4 V, Pt–Sn/C – (A) shows the highest current density value, while at potentials higher than 0.4 V, the Pt–Sn/C – (B) catalyst has the highest activity. The difference of activity of Pt-Sn/C – (A) and Pt-Sn/C – (B) catalyst is attributed to different grade of interaction between platinum and tin for bimetallic catalysts produced from the preparation method and capacity of reduction of reducing agent.

The Pt-Sn/C electrocatalysts performance greatly depends on preparation procedures and Pt:Sn atomic ratios. Here, we synthesized a series of Pt-Sn/C nanoparticle catalyst with a 20% (w/w) metal load (Pt + Sn) on carbon black with a nominal Pt:Sn atomic ratio of 3:1, NaBH4 (A) using and formic acid (B) as reducing agents aiming to study the effect of preparation method on chemical–physical properties of electrocatalyst. The onset potential of ethanol electrooxidation over Pt-Sn/C catalyst was shifted by about 0.03 V negatively in comparison with that over Pt/C catalysts. At lower potential than 0.4 V, Pt–Sn/C – (A) shows the highest current density value, while at potentials higher than 0.4 V, the Pt–Sn/C – (B) catalyst has the highest activity. The difference of activity of Pt-Sn/C – (A) and Pt-Sn/C – (B) catalyst is attributed to different grade of interaction between platinum and tin for bimetallic catalysts produced from the preparation method and capacity of reduction of reducing agent.

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DOI: 10.5151/chemeng-cobeq2014-0883-22832-176633

Referências bibliográficas

• [1] ANTOLINI, E. Catalysts for direct ethanol fuel cells. J. Power Sources, v. 170. p. 1–12, 2007.
• [2] ANTOLINI, E. AND GONZALEZ E. Effect of synthesis method and structural characteristics of Pt–Sn fuel cell catalysts on the electro-oxidation of CH3OH and CH3CH2OH in acid medium. Catal. Today, v. 160, p. 28–38, 2011.
• [3] COLMATI, F.; ANTOLINI, E.; GONZALEZ, E. R. Pt–Sn/C electrocatalysts for methanol oxidation synthesized by reduction with formic acid. Electrochim. Acta, v. 50, p. 5496–5503, 2005.
• [4] CHRISTENSEN, P.; HAMNETT, A.; TROUGHTON, G. The role of morphology in the methanol electro-oxidation reaction. J Electroanal Chem, v 362. P. 207-218, 1993.
• [5] KAPLAN, D.; ALON, M.; BURSTEIN, L.; ROSENBERG, YU.; PELED, E. Study of core–shell platinum-based catalyst for methanol and ethylene glycol oxidation. J. Power Sources, v. 196. p. 1078–1083, 2011.
• [6] KUZNETSOV, V.; BELYI, A.; YURCHENKO, E.; SMOLIKOV, M.; PROTASOVA, M. ZATOLOKINA E.; DUPLYAKIN, V. Mössbauer spectroscopic and chemical analysis of the composition of Sn-Pt/Al2O3 containing components of reforming catalyst. J Catal, v 99. p. 159-170, 1986.
• [7] STEVENS, D.; DAHN, J. Electrochemical Characterization of the Active Surface in Carbon-Supported Platinum Electrocatalysts for PEM Fuel Cells. J Electrochem Soc, v150. p. A770-A775, 2003.
• [8] WANG, K.; GASTEIGER, H.; MARKOVIC, N.; ROSS, P. On the reaction pathway for methanol and carbon monoxide electrooxidation on Pt-Sn alloy versus Pt-Ru alloy surfaces. Electrochim. Acta, v. 41. p. 2587-2593, 1996.

Como citar:

LÓPEZ-SUÁREZ, F. E.; CARVALHO-FILHO, C. T.; BUENO-LÓPEZ, A.; EGUILUZ, K. I. B.; SALAZAR-BANDA, G. R.; "Pt-Sn Catalysts for Ethanol Oxidation in Fuel Cell Systems: Effect of reducing choice", p-7845-7852. In: Anais do XX Congresso Brasileiro de Engenharia Química - COBEQ 2014 [= Blucher Chemical Engineering Proceedings, v.1, n.2]. São Paulo: Blucher, 2015.
ISSN 23591757, DOI 10.5151/chemeng-cobeq2014-0883-22832-176633