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

Why It Matters

The catalyst tackles the twin hurdles of low ENRR activity and HER competition, paving the way for sustainable, ambient‑temperature ammonia production crucial for fertilizer and green‑energy applications.

Key Takeaways

• Carbon doping creates nitrogen vacancies on Mo2N
• Atomic Pb sites suppress hydrogen evolution reaction
• Catalyst achieves 38.7 µg h⁻¹ mg⁻¹ NH3 at –0.1 V
• Stability maintained over 50 hours continuous operation
• DFT links vacancy engineering to lower ENRR energy barrier

Pulse Analysis

Electrochemical nitrogen reduction (ENRR) has emerged as a promising route to synthesize ammonia under ambient conditions, yet its commercial viability is hampered by sluggish kinetics and the pervasive hydrogen evolution reaction (HER). Traditional metal catalysts often favor HER, draining electrons that could otherwise reduce N₂. Consequently, researchers are exploring multifunctional designs that simultaneously activate nitrogen molecules and deter proton reduction, a balance that could unlock scalable, low‑energy ammonia production.

The newly reported catalyst integrates carbon‑bifunctionalized Mo₂N nanoparticles within a hierarchical porous carbon matrix that also hosts atomically dispersed lead (Pb) sites. Interstitial carbon atoms introduce nitrogen vacancies, creating high‑energy sites that enhance N₂ adsorption and facilitate electron back‑donation from Mo d‑orbitals. Simultaneously, the isolated Pb atoms exhibit weak H* binding, effectively suppressing HER without compromising conductivity. This synergistic architecture yields a remarkable ammonia output of 38.7 µg h⁻¹ mg⁻¹ at a modest –0.1 V, and retains activity over 50 hours, demonstrating both efficiency and durability.

Beyond the laboratory, such vacancy‑engineered, HER‑inhibited catalysts could reshape the ammonia market by reducing reliance on the energy‑intensive Haber‑Bosch process. The approach offers a template for other transition‑metal nitrides, encouraging broader adoption of atomic‑scale engineering to tailor electronic structures. Future work will likely focus on scaling the one‑step carbonitridation synthesis, integrating the catalyst into flow‑cell reactors, and evaluating long‑term performance under real‑world conditions, positioning this technology as a cornerstone of the emerging green‑chemistry landscape.