Electrocatalytic oxygen reduction over Co@Co3O4/N-doped porous carbon synthesized by pyrolysis of ZIF-8/67 on cellulose nanofibers

초록

Oxygen reduction reaction (ORR) is important for fuel cells. Despite Pt-based catalysts being considered as the most effective for ORR, their high cost and CO deactivation with low stability limit their practical applications in fuel cell devices. Recently, there has been rapidly growing interest shown in utilizing metal?organic frameworks (MOFs) as a potential candidate for non-Pt based electrocatalysts for ORR. Typically, MOFs can be directly converted into ORR-active materials after carbonization under an inert atmosphere with potentially abundant active sites simply from the choice of metal ions and organic linkers. However, ORR performances of the reported MOF-derived catalysts have been often inferior to the commercially available Pt-based catalysts because of the agglomeration of metal nanoparticles (NPs) occurred during pyrolysis, which reduce the number of active sites and therefore lower the catalytic activity. In this work, we report a facile synthesis of a well-dispersed Co@Co3O4,N co-doped porous carbon without agglomeration of Co NPs (C-Co,N/TOCNF) derived from bimetallic ZIFs (Zn-ZIF-8 and Co-ZIF-67) grown on the surface of cellulose and subsequent pyrolysis treatment. The physicochemical properties of the material were examed using diverse instruments, and it was applied as an ORR electrocatalyst.