Alginate derived Co/N doped hierarchical porous carbon microspheres for efficient oxygen reduction reaction

Exploring biomass-derived non-precious metal carbon-based electrocatalysts have attracted intensive interest in the field of energy conversion due to their low-cost, ecofriendly and sustainable. Herein, we report a novel strategy for preparation of Co/N doped hierarchical porous carbon microspheres (Co/NHPCMS), via pyrolysis ZIF-67@SA/NaHCO 3 microspheres prepared by in-situ growth of ZIF-67 on electrospray Co-SA/NaHCO 3 microspheres. ZIF-67 nanocrystals were well distributed on the ions cross-linked alginate/NaHCO 3 microspheres. The pyrolysis of ZIF-67@SA/NaHCO 3 microspheres could provide abundant active sites and rich porous structure. More importantly, NaHCO 3 plays an essential role in obtaining large mesopores and high pore volume , which is benefit to facilitate the diffusion of reactants. With these merits, Co/NHPCMS-600 exhibits an outstanding ORR electrocatalytic performance with a half-wave potential of 0.827 V. Besides, Co/NHPCMS-600 catalyst exhibits superior catalytic stability and tolerance to methanol in the ORR. This work provides a promising route based on sustainable biomass toward high performance electrocatalyst in the field of energy conversion.