Synthesis of carbon nanotubes on La0.6Sr0.4CoO3 as substrate

A carbon nanotube/perovskite composite material was developed as material for air electrodes in fuel cells or zinc-air batteries. For this purpose, carbon nanotubes were directly grown on the perovskite La0.6Sr0.4CoO3 impregnated with Fe solution which acted as substrate. The synthesis was carried out in a fluidised bed reactor. The carbon source was acetylene. The influence of the temperature on the growth of carbon nanotubes and on the stability of the perovskite was investigated. All samples contained multi-wall carbon nanotubes; however, at a temperature above 675 °C the perovskite was reduced by hydrogen originating from acetylene. The samples with the intact perovskite were further processed to air electrodes to catalyze the oxygen reduction reaction. These electrodes showed an improved performance compared to electrodes made of acetylene black and perovskites.