• Fuentes-Ramirez, R.
• Ledesma-Garcia, J.
• Carrera-Cerritos, Raul
• Ponce De León, C.
• Arriaga, L. G.

Abstract

Full factorial design methodology was applied to the synthesis and optimization of Pd–Ag nanobars using<br/>the polyol process as the reducer. The concentration of Br? ions, the temperature and the reaction time<br/>were selected as factors to study, whereas the yield (% nanobars) was the response to be analyzed. The<br/>nanoparticles were characterized by X-ray diffraction, energy-dispersive X-ray spectroscopy,<br/>transmission electron microscopy, high-resolution transmission electron microscopy and X-ray<br/>photoelectron spectroscopy. The nanoparticles were also tested for the ethanol electro-oxidation<br/>reaction by cyclic voltammetry in alkaline solution. The three factors had a positive effect on<br/>the response: the nanobar yield increased as the level of the variables changed from ?1 to +1. The<br/>temperature and reaction time were the most determinant variables (main and interacting) on the<br/>nanobar yield, whereas the concentration of Br? influenced the yield to a lesser extent. After designing<br/>three optimum experiments, a maximum nanobar yield of 47.3% was obtained. The more negative<br/>electro-oxidation onset, higher current density and more negative current peak potential show that the<br/>incorporation of Ag into Pd nanobars improves the kinetic and thermodynamic behavior towards the<br/>ethanol electro-oxidation reaction compared with that obtained with nanometrically pure Pd nanobars.<br/>This improvement is the result of surface modification caused by the incorporation of Ag in the<br/>formation of Pd–Ag bimetallic nanobars with (200) surfaces.

Topics

• nanoparticle
• density
• impedance spectroscopy
• surface
• x-ray diffraction
• experiment
• x-ray photoelectron spectroscopy
• transmission electron microscopy
• Energy-dispersive X-ray spectroscopy
• current density
• cyclic voltammetry
• photoelectron spectroscopy