Mo₂C-MoO₂ Heterostructure Quantum Dots for Enhanced Electrocatalytic Nitrogen Reduction to Ammonia

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrocatalytic nitrogen reduction reaction (NRR) offers a sustainable route for ammonia synthesis.
• Challenges include poor N2 adsorption/activation and competing hydrogen evolution reaction (HER).
• Efficient electrocatalysts are crucial for advancing ambient ammonia production.

Purpose of the Study:

• To develop novel electrocatalysts for efficient electrocatalytic nitrogen reduction reaction (NRR).
• To investigate the synergistic effects of Mo2C-MoO2 heterostructures for enhanced NRR performance.
• To understand the mechanism of N2 activation and HER suppression.

Main Methods:

• Synthesis of Mo2C-MoO2 heterostructure quantum dots embedded in reduced graphene oxide (RGO).
• Electrochemical characterization of the catalyst for NRR and HER.
• Density functional theory (DFT) calculations to elucidate reaction mechanisms and energetics.

Main Results:

• The Mo2C-MoO2/RGO catalyst achieved a high NH3 yield rate of 13.94 μg h⁻¹ mg⁻¹ at -0.15 V vs RHE.
• A Faradaic efficiency of 12.72% for NRR was obtained at -0.1 V vs RHE.
• DFT calculations confirmed enhanced N2 adsorption on Mo2C and suppressed HER on MoO2.

Conclusions:

• Mo2C-MoO2 heterostructure quantum dots are effective electrocatalysts for ammonia synthesis.
• Synergistic effects promote N2 activation and suppress HER, leading to improved NRR performance.
• This work provides insights into catalyst design for Mo-based electrocatalysts in NRR.