Three-Dimensional Hierarchical Porous Fe, N-Doped Hollow Carbon Nanospheres as Stable Electrocatalyst for Efficient Oxygen Reduction Reaction in Both Acidic and Alkaline Electrolytes

摘要

3D hierarchical porous Fe, N-doped hollow carbon nano-spheres (FeNC HPNCs) as efficient ORR electrocatalyst were obtained using melamine-formaldehyde resin (MF) nano-spheres as thermal sacrificial hard template to optimize the pore structure and provide nitrogen source to the catalyst. The optimized FeNC HPNCs catalyst exhibited excellent catalytic activity with onset (E_(onset)) and half-wave (E_(1/2)) potential (E_(onset) = 1.07 V; E_(1/2) = 0.90 V vs. RHE) superior to commercial Pt/C catalyst in 0.1 M KOH solution, and demonstrated excellent stability. When applied as cathode electro-catalyst in a Zn-air battery, it produced maximum power density (P_(max)) of 127mWcm~(-2), which is higher than that of commercial Pt/C (P_(max)= 119 mWcm~(-2)). It also showed good activity (E_(onset) = 0.89 V; E_(1/2) = 0.78 V) in 0.1 M HClO4 electrolyte with significantly enhanced stability (△E_(1/2) =7 mV) relative to the Pt/C catalyst (△E_(1/2) =27 mV).