Single Atoms Anchored on Cobalt-Based Catalysts Derived from Hydrogels Containing Phthalocyanine toward the Oxygen Reduction Reaction

Herein, a novel hydrogel-derived three-dimensional network-like nanostructured CoO_X/Co–N–C­(800) catalyst was synthesized. CoO_X nanoparticles are embedded on N-doped carbon with single Co atoms anchored after pyrolysis. The as-prepared CoO_X/Co–N–C­(800) catalyst possesses excellent electrochemical performance toward the oxygen reduction reaction with a positive onset and half-wave potential of 0.95 and 0.88 V (vs RHE), respectively, including almost a four-electron pathway (3.97) and better durability compared with the 20% commercial Pt/C catalyst in an alkaline electrolyte. Also, the results demonstrate that the high performance is attributed to the synergistic effect of CoO_X nanoparticles and single Co atoms.