High performance and durability of polymer-coated Pt electrocatalyst supported on oxidized multi-walled in high-temperature polymer electrolyte fuel cells

The low durability and fuel cell performance of the platinum electrocatalyst block the widespread application of high-temperature polymer electrolyte fuel cells (HT-PEFCs). Here, we utilize a facile method to improve the durability as well as fuel cell performance of the platinum electrocatalyst supported on oxidized multi-walled carbon nanotubes (ox-CNT/Pt), in which the electrocatalyst is coated by polybenzimidazole assisted by the COOH groups on the surface of ox-CNT. The coated and non-coated electrocatalysts remain 50% of the initial electrochemical surface areas (ECSAs) after 350,000 and 50,000 potential cycles from 1.0 to 1.5 V vs. RHE, respectively, indicating that polymer coating enhances the durability of the electrocatalyst. Meanwhile, power density of PBI-coated electrocatalyst measured under anhydrous condition is 1.6 times higher compared to that of non-coated electrocatalyst due to the PBI layer acted as proton conductor in the catalyst layer. This study offers useful knowledge for enhancement of durability and performance of Pt electrocatalyst used in HT-PEFCs.