Design of polymer-coated multi-walled carbon nanotube/carbon black-based fuel cell catalysts with high durability and performance under non-humidified condition

To realize a high catalyst utilization, better fuel cell performance and durability as well as low production cost, an efficient design strategy of the catalyst layer that can improve both the oxygen accessibility and structure stability is highly required. Here, we describe the preparation of fuel cell electrocatalysts with an efficient fuel cell performance and better stability based on hybrids of multi-walled carbon nanotubes (MWNTs) and carbon black (CB) which were wrapped by a proton conducting polymer, poly[2,2′-(2,6-pyridine)-5,5′-bibenzimidazole], before deposition of the platinum (Pt) metal catalyst. The catalyst mass activity after feeding only 10%-MWNTs to CB increased by 1.5 and 2 times than those of the MWNTs-based- and CB-based catalysts, respectively. The results also demonstrated that 90 wt% of the MWNTs in the catalyst layer allows it to be replaced by CB without any significant change in its durability and performance under 120 °C and non-humidified condition.