Synthesis and characterization of a carbon supported transition metal phosphide for the oxygen evolution reaction

Kurzfassung

Metal-air batteries have been received increasingly more attention because of their remarkably high energy density when compared to other types rechargeable batteries, such as lithium-ion. Even though, they are promising source of power for next-generation electronics, transportation and energy storage, they still have numerous technical challenges that must be overcome. This work aims at to develop non-noble transition metal catalysts to improve the overall performance of metal-air batteries and provide an alternative to noble metal-based catalysts, which suffer from multiple disadvantages such as high cost and poor stability. Four catalysts were studied for the positive electrode targeting the enhancement of the oxygen reduction/evolution reactions. Transition-metal phosphides and carbon supported catalysts were synthesized, tested and characterized (in situ and ex situ). Based on literature information and on the experience of the research team, Ni2P, Ni2P/CNT, Ni2P-Fe/CNT and Ni2P-Fe2O3/CNT were prepared and characterized and their performance assessed. It was proved that the addition of a carbon support improves the reactions current density and the synthesis of a bi-metal catalyst improves considerably the activity of catalysts. Furthermore, it was developed a new catalyst which improves considerably the performance of the oxygen evolution reaction compared with the reference iridium black electrode.