Iron Phthalocyanine Coated Nitrogen-doped Hollow Carbon Spheres for Efficient Catalysis of Oxygen Reduction Reaction

It is imperative to develop low-cost and high-performance catalysts for oxygen reduction reaction（ORR）. Although iron phthalocyanine（FePc）has been proved as an efficient catalyst for ORR decades ago，it cannot replace commercial Pt/C due to its poor electronic conductivity and unsatisfied stability. Considering the chemical stability，high electronic conductivity，and intrinsic catalytic activity of nitrogen-doped carbons，herein，FePc coated nitrogen-doped hollow carbon（FePc-NHC）has been fabricated by carbonization of polystyrene@polydopamine spherical precursors，followed by the loading of FePc. A series of hollow spherical FePc-NHCS samples was prepared by adjusting the pyrolysis temperature and loading amount of FePc. Benefiting from the hierarchical porous structure，high specific surface area，proper nitrogen doping，and FePc loading，the optimized FePc-NHCS displayed an excellent catalytic activity for ORR in alkaline electrolyte，with a remarkable long-term stability and a high half-wave potential of 0.862 V（vs. RHE），outperforming Pt/C（0.848 V）. This work proved that hybridization is an effective pathway to strength the positive properties of each component. Also，structural and compositional modification is efficient to optimize the ORR performance of a catalyst.