Template-free synthesis of hierarchical peanut-like Co and N codoped porous carbon with highly efficient catalytic activity for oxygen reduction reaction

• The peanut-like Co and N codoped porous carbon catalyst had been synthesized.
• The formation process of the peanut-like precursor was investigated in-depth.
• The Co/N-PC possessed a comparable ORR half-wave potential to that of Pt/C.
• The high ORR activity of the Co/N-PC was mainly ascribed to the unique structure.

Studies have shown that the performance of electrode materials greatly depends on their structures and compositions. Herein, unique hierarchical peanut-like Co and N codoped porous carbon (Co/N-PC) had been synthesized by using inexpensive melamine, formaldehyde and cobalt acetate as raw materials via a simple template-free hydrothermal reaction followed by heat treatment. The formation process of the peanut-like precursor was discussed in-depth, indicating that the morphological evolution with time followed a pathway of: solid microspheres → wrinkled and ultrathin shells wrapped microspheres → the peanut-like precursor formation. Furthermore, the unique structure combines the advantageous features of high surface area, sufficient active sites, easy access to medium and rapid mass transport. As a result, the peanut-like Co/N-PC showed high catalytic activity, superior methanol crossover resistance and excellent catalytic stability towards oxygen reduction reaction (ORR) in alkaline medium. Notably, the peanut-like Co/N-PC possessed a comparable ORR half-wave potential to commercial 20 wt% Pt/C catalyst. Therefore, it can be expected that the peanut-like Co/N-PC will be a promising alternative to commercial Pt/C catalyst for fuel cells.