What question did this study set out to answer?

This research aims to develop an efficient catalyst for nitrogen reduction to improve ammonia synthesis.

January 14, 2026Small0 citations

Carbon‐Bifunctionalized Mo 2 N Coupled Atomic Pb Sites for Efficient Nitrogen Reduction

QYQingqing YeZhengzhou University JMJun ManFuel Cells and Hydrogen YHYixuan HuangBeijing University of Chemical Technology

Key Points

This research aims to develop an efficient catalyst for nitrogen reduction to improve ammonia synthesis.
Designed a carbon-bifunctionalized Mo 2 N catalyst within a porous carbon matrix with atomic lead sites.
Conducted density functional theory calculations to analyze the reaction mechanisms.
Assessed the catalyst's performance in terms of ammonia yield and operational stability.
The optimized catalyst produced 38.7 µg h −1 mg −1 of ammonia at -0.1 V with 50 hours of stability.
Atomic dispersion of lead effectively suppressed hydrogen evolution due to weak H * affinity.
Carbon-induced nitrogen vacancies improved the catalyst's activation and electron donation capabilities.

Abstract

Abstract The electrocatalytic nitrogen reduction reaction (ENRR) offers a sustainable pathway for ambient ammonia (NH 3 ) synthesis but suffers from kinetic limitations and competing hydrogen evolution (HER). Herein, a new type of ENRR catalyst is designed consisting of carbon‐bifunctionalized Mo 2 N nanoparticles (NPs) embedded in a hierarchical porous carbon matrix with atomic Pb sites (PbNC) through a one‐step carbonitridation strategy. The carbon‐bifunctionalization effect not only creates nitrogen vacancies through interstitial carbon doping to form molybdenum carbonitride (Mo 2 CN) phase that enhances N 2 adsorption and activation, but also stabilizes active sites via nanoconfinement of the in situ formed carbon layer on Mo 2 CN NPs. Concurrently, the atomically dispersed Pb within the PbNC matrix suppresses HER due to its weak H * affinity. The optimized catalyst demonstrates 38.7 µg h −1 mg −1 NH 3 yield at a low potential of −0.1 V with 50 h operational stability. Density functional theory calculations reveal that carbon‐induced nitrogen vacancies modulate the Mo d‐band center, which facilitates electron back‐donation to N 2 and thus shifts the potential‐determining step from initial protonation to the NH 3 desorption step via the Mars‐van Krevelen mechanism with a lower energy barrier for ENRR. This study proposes an integrated approach involving vacancy engineering, atomic‐level HER suppression, and nanoconfinement toward efficient ENRR catalysis.

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