Efficient nitrogen-doped porous carbon/carbon nanotube-supported CO3O4/Co catalysts for oxygen reduction reactions in alkaline media

In this study, Co3O4/Co nanoparticles are synthesized within nitrogen-doped porous carbon/carbon nanotube matrix (Co3O4/Co@NC/CNT) by using ZIF-67 metal-organic frameworks. In comparison with commercial Pt/C catalysts, the composite exhibits better electrocatalytic characteristics for oxygen reduction reactions in alkaline media, such as onset potential, half-wave potential, current density, cycle stability, and methanol tolerance. For instance, onset potential and half-wave potential are positively shifted by 67 mV and 25 mV, respectively. Structural and composition analysis demonstrate that enhanced properties result from the formation of pyridinic nitrogen and Co-N-C active sites within carbon matrix. The findings above indicate that the Co3O4/Co/Co@NC/CNT catalyst can replace expensive Pt/C catalyst for potential applications in fuel cells and metal-air batteries.