Efficient Electrochemical N₂ Fixation over Donor-Acceptor FeEu─N₄ Active Site

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrocatalytic nitrogen reduction reaction (NRR) is crucial for sustainable ammonia production.
• Current NRR methods suffer from low Faradaic efficiency (FE) and ammonia yield rates.
• Developing efficient and selective electrocatalysts remains a significant challenge.

Purpose of the Study:

• To develop an innovative catalyst for enhanced electrocatalytic nitrogen reduction reaction (NRR).
• To investigate the mechanism of improved NRR performance using a FeEu─NC catalyst.
• To provide insights into designing efficient electrochemical nitrogen fixation systems.

Main Methods:

• Synthesis of a novel FeEu─NC catalyst.
• Electrocatalytic performance testing for NRR, including ammonia yield and Faradaic efficiency.
• Experimental characterization to elucidate the catalytic mechanism, including electron transfer and N2 activation.

Main Results:

• The FeEu─NC catalyst achieved an ammonia yield of 221.6 µg h⁻¹ mg⁻¹ and FE of 61.1%.
• Electron transfer from Eu to Fe atoms was shown to weaken the N≡N bond and enhance N2 activation.
• The catalyst demonstrated preferential NRR over hydrogen evolution reaction (HER), indicated by differing limiting potentials.

Conclusions:

• The FeEu─NC catalyst significantly enhances electrocatalytic NRR performance.
• Intermetallic electron transfer is a key strategy for designing highly active and selective NRR electrocatalysts.
• This work offers a blueprint for efficient electrochemical nitrogen fixation systems.