·H effectively enhance electrocatalytic nitrogen fixation.

Area of Science:

• Electrocatalysis
• Green Chemistry
• Materials Science

Background:

• Electrocatalytic nitrogen reduction reactions (NRR) for ammonia production often suffer from low yields and poor Faradaic efficiency.
• Existing electrocatalysts struggle to overcome the high activation energy of NRR and suppress competing hydrogen evolution reactions (HER).

Purpose of the Study:

• To introduce a novel approach using hydroxyl radicals (·OH) to enhance electrocatalytic nitrogen reduction reactions (NRR).
• To investigate the mechanism by which ·OH radicals improve ammonia synthesis and inhibit HER.
• To achieve high ammonia yields, stability, and Faradaic efficiency in electrocatalytic NRR.

Main Methods:

• Generation of ·OH radicals from sulfite (SO3^2-) and water under UV irradiation.
• Electrochemical measurements including ammonia yield, Faradaic efficiency (FE), and stability tests at -0.3 V vs. RHE.
• In situ spectroscopic techniques (FTIR, ESR) and computational methods (DFT, 1H NMR) to elucidate the reaction mechanism.

Main Results:

• Achieved high ammonia yields of 100.7 μg h⁻¹ mg⁻¹cat.
• Demonstrated excellent stability for 64 hours.
• Obtained a maximum Faradaic efficiency of 27.1% under UV irradiation.
• ·OH radicals were confirmed to lower the NRR energy barrier and suppress HER.

Conclusions:

• Hydroxyl radicals (·OH) represent a promising strategy for advancing electrocatalytic nitrogen reduction reactions.
• This method offers a new pathway for efficient and selective ammonia synthesis.
• The findings provide valuable insights for designing future electrocatalysts and reaction systems.