Copper-promoted nitrogen-doped carbon derived from zeolitic imidazole frameworks for oxygen reduction reaction

摘要

Rational design of oxygen reduction reaction (ORR) electrocatalysts based on earth-abundant elements is critical important towards sustainable energy applications. Among various reported ORR electrocatalysts, transition metal-nitrogen doped carbon (TM-N/C) materials such as Fe-N-x/C and Co-N-x/C exhibit excellent catalytic activity. Nevertheless, comprehensive understanding of these TM-N/C electrocatalytic systems is still lacking, which demands extension of investigation to other TM-N/C systems (Cu, and Mn, etc.). Herein, we developed a Cu promoted nitrogen-doped carbon (Cu-N/C) via high temperature pyrolysis of Cu-adsorbed zeolite imidazole frameworks (Cu@ZIF-8). The Cu-N/C electrocatalyst exhibited satisfactory ORR activity with half-wave potential of 0.813 V in 0.1 M KOH electrolyte. Moreover, it also showed excellent methanol tolerance and long-term stability. The enhanced ORR electrocatalytic performance is attributed to the strong synergetic effect between Cu(II)-N ligands and Cu-0 NPs, sufficient active sites, and fast mass transfer.