Iron Carbide Nanoparticles Supported by Nitrogen-Doped Carbon Nanosheets for Oxygen Reduction

Abstract

Collocation of a suitable catalyst and support is a classic way to tune the activity and stability of catalysts. Herein, we designed a self-sacrificial reagent-directed route to synthesize iron carbide nanoparticles inlaid in a N-doped carbon nanosheet (Fe3C–N–C). With the introduction of the sacrificial reagent, the chemical Fe–N bonds in Fe3C–N–C increases and the size of Fe3C becomes smaller, further leading to uniform dispersion. With the increase of chemical Fe–N bonds, Fe3C–N–C ensures structural stability and prevents surface poisoning and agglomeration. Notably, the Fe3C–N–C catalyst exhibits much higher oxygen reduction reaction activity (E0 = 0.94 V, E1/2 = 0.82 V), longer stability (ΔE = −15 mV), and better methanol tolerance than 20% Pt/C (E0 = 0. 98 V, E1/2 = 0.85 V, ΔE = −27 mV). Fe3C–N–C materials can also be assembled into Li–O2 batteries taking advantage of their large discharge capacity and excellent cycling stability. Our findings guide in designing advanced carbon-supported metal catalysts.