Optimization of cobalt on CNT towards the oxygen evolution reaction and its synergy with iron (II) phthalocyanine as bifunctional oxygen electrocatalyst

Monometallic cobalt catalysts supported on carbon nanotubes (Co/CNT) were optimized for the oxygen evolution reaction (OER). The optimized Co/CNT catalyst was physically mixed with another catalyst composed of carbon nanotubes and iron phthalocyanine to achieve an electrocatalyst able to catalyse both the OER and the oxygen reduction reaction (ORR). A 1:1 mass ratio provided a similar OER electroactivity in comparison to the monometallic catalyst (1.64 V) and a high half-wave potential (0.88 V), which is much higher than that of the commercial Pt/C (0.83 V). This sample also produced the lowest potential gap (0.76 V), which is much lower than the commercial electrocatalysts and most state-of-the-art carbon-supported electrocatalysts.