Electroreduction of oxygen on cobalt phthalocyanine-modified carbide-derived carbon/carbon nanotube composite catalysts

Abstract

In this work, composite materials based on carbide-derived carbon (CDC) and carbon nanotubes (CNT) modified with Co phthalocyanine (CoPc) were employed as electrocatalysts towards the oxygen reduction reaction (ORR) in both alkaline and acid media. Two different CDCs derived from titanium carbide and silicon carbide were used and the CDC-to-CNT ratio was varied in the composite materials. The final catalysts were obtained after pyrolysis at 800 °C. The catalyst materials were characterised by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and microwave plasma atomic emission spectroscopy. The ORR measurements were performed using the rotating disk electrode (RDE) method. The RDE results revealed that the composite catalysts with higher CNT content possessed higher ORR electrocatalytic activity. The catalyst showing the highest activity in RDE tests was selected as a cathode material and tested in an anion exchange membrane fuel cell (AEMFC). An excellent AEMFC performance was obtained, with a peak power density of 473 mW cm−2.