Atomically Dispersed Fe₁Mo₁ Dual Sites for Enhanced Electrocatalytic Nitrogen Reduction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrocatalytic nitrogen reduction reaction (eNRR) offers a sustainable route for ammonia (NH3) production.
• Challenges in eNRR include poor N2 adsorption and high hydrogenation energy barriers.
• Atomically dispersed dual-site catalysts show promise for complex hydrogenation reactions like eNRR.

Purpose of the Study:

• To design and synthesize an atomically dispersed Fe1Mo1 dual-site catalyst anchored in nitrogen-doped carbon (FeMo-NC).
• To investigate the catalyst's performance for the electrocatalytic nitrogen reduction reaction.
• To elucidate the mechanism of enhanced catalytic activity using DFT calculations.

Main Methods:

• Synthesis of atomically dispersed Fe1Mo1 dual sites on nitrogen-doped carbon.
• Electrochemical measurements to evaluate NH3 yield rate and Faradaic efficiency.
• Density Functional Theory (DFT) calculations to study N2 adsorption and reaction pathways.

Main Results:

• The FeMo-NC catalyst achieved a maximum NH3 yield rate of 1.07 mg h-1 mgmetal-1 and a Faradaic efficiency of 21.7% at -0.25 V vs RHE.
• The catalyst outperformed many reported non-noble metal electrocatalysts for eNRR.
• DFT calculations confirmed strong N2 activation via side-on adsorption and optimized intermediate binding energies.

Conclusions:

• The Fe1Mo1 dual site effectively activates N2 and lowers the hydrogenation barrier for eNRR.
• The developed catalyst presents a promising strategy for efficient and green ammonia synthesis.
• Atomically dispersed dual-site catalysts are highly effective for challenging hydrogenation reactions.