Cu-Doped Iron Oxide for the Efficient Electrocatalytic Nitrate Reduction Reaction

Area of Science:

• Electrochemistry
• Catalysis
• Sustainable Chemistry

Background:

• Electrochemical nitrate reduction reaction (NO3RR) offers sustainable ammonia (NH3) production and water remediation.
• Challenges include complex eight-electron transfer and hydrogen evolution reaction competition.
• High-activity and high-Faradaic-efficiency (FE) catalysts are crucial for improving NO3RR performance.

Purpose of the Study:

• To develop efficient catalysts for electrochemical nitrate reduction to ammonia.
• To investigate the effect of copper doping on iron oxide catalysts for NO3RR.
• To understand the mechanism of enhanced NO3RR activity through theoretical calculations.

Main Methods:

• Fabrication of copper-doped Fe3O4 flakes.
• Electrochemical characterization of catalyst performance (FE, NH3 yield).
• Density Functional Theory (DFT) calculations to study reaction mechanisms.

Main Results:

• Cu-doped Fe3O4 flakes exhibited excellent catalytic activity for NO3RR.
• Achieved a maximum FE of ~100% and NH3 yield of 179.55 ± 16.37 mg h-1 mgcat-1 at -0.6 V vs RHE.
• Theoretical calculations confirmed that Cu doping facilitates the reaction thermodynamically.

Conclusions:

• Cu-doped Fe3O4 flakes are highly effective catalysts for electrochemical nitrate to ammonia conversion.
• Heteroatom doping is a feasible strategy to enhance NO3RR activity.
• This work demonstrates a promising approach for sustainable ammonia synthesis.