Over the years, production of energy has been based on fossil fuels, which naturally arose millions of years ago and include carbon, natural gas and oil. During power generation, these materials generate high concentrations of CO₂ in the atmosphere that are harmful to the environment. In addition, it is expected that by 2050 the oil and natural gas will be exhausted.¹

A good alternative for power generation are fuel cells, which are devices that convert chemical energy into electrical energy, but for continuous production must implement a continuous supply of reagents. These cells have the advantage of generating energy through chemical processes rather than combustion, thus generating clean processes.

In some fuel cells, such as hydrogen/oxygen cell, the limiting reaction is oxygen reduction, so some studies have focused on optimizing this process. In these cells, the following reactions are performed:²

Anodic reaction (oxidation)         H₂ → 2 H⁺ + 2 e^-                                E°=0.000 V

Cathodic reaction (reduction)     O₂ + 4 H⁺ + 4e^- → 4 H₂O                   E°=+1.229 V

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Overall reaction                          2 H⁺  + O₂ → 2 H₂O                          E°=+1.229 V

A primary component of fuel cells is the catalyst which is responsible for accelerating the reaction and it’s regenerated at the end. Platinum is the most used noble metal as electrocatalyst in fuel cells because of its high activity and stability, however one of the major challenges is inactivity of platinum caused by carbon monoxide. To overcome this challenge has been proposed Pt alloy with Cu, since it has been reported that Pt alloy to non-noble metals generates higher catalytic activity in the reduction reaction of oxygen compared with platinum alone.³

In this work we compares the catalytic activity in the reduction reaction of oxygen of PtCu/MWCNT synthesized by inverse microemulsion against ultrasound assisted synthesis, which has the advantage of being a green synthesis to be free of solvents and organic surfactants.

References

1. Cyber quote on: Proyecto de educación ambiental. Virtual page Cambio climático, http://unidades.climantica.org/es/unidades/02/crise-enerxetica-e-cambio-climatico/o-esgotamento-dos-combustibles-fosiles-e-o-cambio-climatico/1, february 3rd of 2015.
2. Ojani, R; Valiollahi, R.; Raoof, J.B. Energy 2014, 74, 871 – 876.
3. Maillard, F.; Martin, M.; Gloaguen, F.; Leger, J. M. Electrochim. Acta 2002, 47, 3431 – 3440.