Preparation of self-nitrogen-doped porous carbon nanofibers and their supported PtPd alloy catalysts for oxygen reduction reaction

摘要

There are many types of cathodic oxygen reduction catalysts for proton exchange membrane fuel cell (PEMFC). Among them, Pt-based catalysts are most likely to be industrialized because of their incomparable high activity. However, most of the Pt-based catalysts have not reached the maximum activity and stability. Herein, porous carbon nanofibers (p-CNF) with self-nitrogen-doped as catalyst supports were successfully prepared by the method of electrospinning. After functionalization, the functionalized porous carbon nanofibers (f-p-CNF) were loaded with PtPd alloy nanoparticles to obtain the catalyst (Pt0.66Pd0.33/f-p-CNF), which has excellent electrochemical performance. Its specific activities (SA) and Pt mass activities (Pt MA) are 1.73 and 1.86 times of the commercial JM 20% Pt/C (JM20), respectively. The results can be attributed to the porous structure of nanofibers, which not only facilitate the transmission of gas-liquid and electron but also increase the exposure of active sites. And the doped nitrogen of fibers may regulate the electronic structure of the metal active substance to increase the activity. This work provides catalyst with novel structure which could enable PEMFCs to be more efficient in operation.