The durability of polymer electrolyte membrane fuel cells (PEMFCs) is a key issue to be improved, especially for the next generation of PEMFCs that will be required to operate at higher temperatures (> 100 °C). An improvement of the durability of PEMFCs by using carbon nanotubes (CNTs) in place of carbon black as the support material for platinum catalysts is reported. To explore the mechanism for the enhancement of the durability as well as the structural dependency on the type of CNTs, accelerated durability tests are performed using several types of CNTs, which include multi-walled CNTs (MWCNTs) and single-walled CNTs (SWCNTs) loaded with Pt nanoparticles. By comparing the electrochemical surface area degradation and CNT oxidation profiles of their Pt composites, the electrochemical stability of CNTs is revealed to dominate the stability of the Pt. MWCNT having larger diameter with lower degree of side-wall defects offer a better durability than smaller MWCNT and also than SWCNTs. We found that onset temperature in the thermogravimetric analysis and their profiles provide an insight for predicting the durability of their Pt composites, which is useful for selecting of optimum CNTs.
!!!All Science Journal Classification (ASJC) codes
- 化学 (全般)