Oxygen reduction on PtFe/C electrocatalysts prepared in microemulsions

• Autor(a) principal: Malheiro, A. R. [UNESP]
• Data de Publicação: 2008
• Outros Autores: Perez, J. [UNESP], Villullas, H. M. [UNESP]
• Tipo de documento: Artigo de conferência
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.1149/1.2943227; http://hdl.handle.net/11449/70869
• topic: Average compositions; Electrocatalytic activities; Energy dispersive; Methanol tolerances; Microemulsion methods; Nano-catalysts; Overpotentials; Oxygen reductions; Ray analyses; Room temperatures; Rotating disk electrodes; Sulfuric acid solutions; Tafel plots; X-ray diffractions; Blood vessel prostheses; Catalysis; Chemical analysis; Disks (machine components); Electrocatalysis; Electrocatalysts; Electrochemistry; Electrolysis; Electrolytic reduction; Energy conversion; Methanol; Microemulsions; Oxygen; Particle size; Platinum; Reduction; Rotating disks; Sulfuric acid; X ray analysis; Particle size analysis

PtFe/C nanocatalysts of different compositions and nearly constant particle size were prepared by a microemulsion method. Crystallite sizes and degree of alloying were determined by X-ray diffraction. Particle size and distribution were characterized by transmission electron microscopy and average composition was determined by energy dispersive X-ray analysis. Measurements of electrocatalytic activity for oxygen reduction were done using the rotating disk electrode technique in O2 saturated 0.5 mol L-1 sulfuric acid solutions, at room temperature. For all catalysts oxygen reduction begins at ̃ 0.90V. Tafel plots show slopes of c.a. 60 and 120 mV dec in the regions of low and high overpotentials, respectively. The best results for the ORR were obtained for the PtFe/C catalyst of composition Pt:Fe 70:30. This catalyst was also found to exhibit the largest methanol tolerance. © The Electrochemical Society.