Abstract: The catalytic layers of proton exchange membrane fuel cells prepared by spraying or transfer printing methods have problems of uneven activity or easy failure of active sites. In this study, a flexible carbon nanofiber film with high conductivity was prepared by electrospinning, and then Cu with high hydrogen evolution potential was uniformly deposited on the fiber film by pulse electrodeposition to prepare Cu nanocrystal@PtCu/carbon nanofiber film. Finally, a Cu@PtCu/carbon nanofiber (Cu@PtCu/CNF) catalytic film was synthesized by situ exchange reduction. The Cu@PtCu/CNF catalytic film solves the problem of uneven activity of the catalytic layer. It can be directly used as the catalytic layer. Its morphology and structure were characterized by SEM, XRD, XPS. The electrochemical test results show that Cu@PtCu/CNF catalytic films obtained at pH=4 and chloroplatinic acid concentration of 0.25 m·mL^-1 have an area specific activity of 49 m²·g^-1. After 5 000 cycles of stability testing, the electrochemically active specific surface area remains 74%, and the half-wave potential decreases by 9 mV, both better than commercial Pt/C catalysts.

Key words: catalyst film, carbon nanofiber film, electrospinning, electrodeposition, oxygen reduction reaction, Cu@PtCu