Bottom-up assembly of carbon nanotubes electrocatalyst for polymer electrolyte fuel cell
【摘要】：Polybenzimidazole (PBI: Fig. 1) is widely known as a promising candidate for electrolyte membrane of polymer electrolyte fuel cell (PEFC) operating under dry condition. On the other hand, carbon nanotubes (CNTs) have been emerged as a better carbon support material than conventional material such as carbon black. We have reported the PBI is adsorbed onto the surface of CNTs and acts as the good solubilizer . By taking advantage of stable wrapping of PBI on CNTs, we utilized this composite as a novel carbon supporting materials for loading the metal catalyst such as platinum (Pt). As the result, the PBI-wrapped CNTs show better efficiency of Pt loading than that of pristine CNTs due to the coordination between Pt ion and PBI. Furthermore, the obtained electrocatalyst (CNT/PBI/Pt) shows excellent Pt utilization efficiency mainly due to the formation of ideal interfacial structure constructed by the CNTs, PBI and Pt . However, we also noticed the electrochemically active area (ECSA) was gradually decreased during long time operations caused by the aggregation of the Pt.