Design and assembly of ZIF@PPy-derived hierarchical structure CeCo-NxCC electrocatalyst towards oxygen reduction reaction

The research of high-performance catalysts for ORR is always a great challenge in the field of zinc-air batteries (ZABs) applications. Herein, a near-regular dodecahedral ZIF-67-derived nitrogen-doped carbon material (CeCo-NxCC-700) with abundant hollow nanospheres on the surface is successfully constructed by introducing Ce ions to replace part of the Co ions and polymerizing pyrrole on the surface of the polyhedrons. PPy-coating is beneficial to improving the electrochemical stability and increasing the number of Co-Nx active sites, especially the pyrrole N and pyridine N sites. Ce-doping adjusts the charge density around the active sites. Meanwhile, the pyrolysis at 700 °C during the preparation process does not cause the structural collapse of CeCo-NxCC. Based on their decent ORR/OER performance, ZABs have been further assembled with CeCo-NxCC-700, which exhibit a high specific capacity of 815.4 mAh·g (Zn)−1 and cycling stability of more than 80 h, indicating a great application potentiality in ZABs manufacturing.