Carbon-Bifunctionalized Mo₂N Coupled Atomic Pb Sites for Efficient Nitrogen Reduction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrocatalytic nitrogen reduction reaction (ENRR) is a sustainable method for ammonia synthesis.
• Kinetic limitations and competing hydrogen evolution reaction (HER) hinder ENRR efficiency.

Purpose of the Study:

• To design and synthesize a novel catalyst for efficient ENRR.
• To suppress HER and enhance N2 adsorption and activation.

Main Methods:

• One-step carbonitridation strategy to create carbon-bifunctionalized Mo2N nanoparticles (NPs) embedded in a hierarchical porous carbon matrix with atomic Pb sites (PbNC).
• Utilizing interstitial carbon doping to form molybdenum carbonitride (Mo2CN) phase and create nitrogen vacancies.
• Employing density functional theory (DFT) calculations to understand the catalytic mechanism.

Main Results:

• The optimized PbNC catalyst achieved an NH3 yield of 38.7 µg h-1 mg-1 at -0.1 V with 50 h stability.
• Carbon-bifunctionalization enhanced N2 adsorption/activation and stabilized active sites via nanoconfinement.
• Atomic Pb sites effectively suppressed HER due to weak H* affinity.

Conclusions:

• The developed catalyst demonstrates high efficiency and stability for electrocatalytic ammonia synthesis.
• Nitrogen vacancies and atomic Pb sites are crucial for enhancing ENRR performance and suppressing HER.
• This study presents an integrated approach for advanced ENRR catalyst design.