Interfacial Curvature-Induced Electronic Modulation in Carbon-Encapsulated Fe₃C for the Oxygen Reduction Reaction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Precise control of interfacial electronic structure is key for high-performance metal carbide catalysts.
• Carbon encapsulation is a promising strategy for catalyst design.

Purpose of the Study:

• To investigate the effect of interfacial curvature on the electronic properties of N-doped carbon-encapsulated Fe3C (Fe3C@NC) catalysts.
• To evaluate the electrocatalytic performance of Fe3C@NC for oxygen reduction reactions and its application in Zn-air batteries.

Main Methods:

• Synthesis of N-doped carbon-encapsulated Fe3C (Fe3C@NC) catalyst.
• Structural characterization using advanced techniques.
• Density functional theory (DFT) calculations to understand electronic structure and reaction mechanisms.
• Electrochemical testing in alkaline media and Zn-air battery performance evaluation.

Main Results:

• The intrinsic curvature of the carbon shell induces significant interfacial electronic modulation in Fe3C@NC.
• Curvature-driven electron redistribution optimizes Fe 3d states, enhancing oxygen adsorption and conversion to *OOH.
• Fe3C@NC exhibits a high onset potential (1.03 V vs RHE) and half-wave potential (0.90 V vs RHE) for oxygen reduction with excellent durability.
• The catalyst achieved a high peak power density of 187.5 mA cm⁻² in a Zn-air battery.

Conclusions:

• Interfacial curvature is a critical parameter for tuning the electronic properties of metal carbide catalysts.
• Fe3C@NC demonstrates superior electrocatalytic activity and durability for oxygen reduction, driven by electronic structure optimization.
• This work provides insights into the rational design of advanced inorganic electrocatalysts for energy applications.