Fullerene-metalloporphyrin co-crystal as efficient oxygen reduction reaction electrocatalyst precursor for Zn-air batteries

Fullerene-derived carbon materials are promising catalysts for the oxygen reduction reaction (ORR) because of the presence of intrinsic defects in the carbon cage. Moreover, the nitrogen (N) species and metallic catalytic sites can effectively overcome the sluggish kinetics of O₂ activation. In this work, a rod-shaped tetraphenyl-porphyrin cobalt-C₆₀ cocrystal (CoTPP/C₆₀) was self-assembled and then annealed to prepare a series of N, Co-codoped carbon materials. Among the resulting CoTPP/C₆₀-X materials, CoTPP/C₆₀-800, which was obtained at 800 °C, demonstrated a half-wave potential of 0.824 V_RHE, outstanding stability, and remarkable methanol tolerance. The superior ORR performance of CoTPP/C₆₀-800 can be attributed to the presence of abundant defects, appropriate N species (pyridine N and graphitic N), Co–N_x sites, and Co nanoparticles. Moreover, a Zn-air battery assembled using CoTPP/C₆₀-800 as the cathode exhibited a high power density of 111.7 mW∙cm⁻². This study provides a new strategy for designing and synthesizing advanced ORR catalysts for Zn-air batteries.