Hydrogen Radical-Induced Electrocatalytic N₂ Reduction at a Low Potential

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Efficient electrocatalytic nitrogen reduction reaction (NRR) is critical for ammonia synthesis.
• The initial hydrogenation step in NRR requires a high equilibrium potential, hindering efficiency.
• Existing NRR mechanisms lack experimental validation and efficient strategies.

Purpose of the Study:

• To investigate a novel hydrogen radical-transferring mechanism for electrocatalytic NRR.
• To develop an efficient electrocatalyst for NRR with high activity and selectivity at low potentials.
• To provide experimental evidence for the proposed catalytic pathway.

Main Methods:

• Synthesis of ruthenium single atoms anchored on graphdiyne/graphene sandwich structures.
• Electrochemical characterization to evaluate catalytic performance.
• Mechanistic studies involving hydrogen radicals (H•) and NNH radicals (•NNH).

Main Results:

• The developed electrocatalyst demonstrated a hydrogen radical-transferring mechanism.
• Graphdiyne (GDY) generated H•, activating N2 to •NNH, while Ru sites promoted further hydrogenation.
• High activity and selectivity for ammonia synthesis were achieved at -0.1 V vs. RHE.

Conclusions:

• A novel hydrogen transfer mechanism significantly reduces the potential required for NRR.
• The dual-active site design effectively suppresses hydrogen evolution, enhancing selectivity.
• This study offers a new design strategy for highly efficient electrocatalysts for NRR.