Graphdiyne Enabled Nitrogen Vacancy Formation in Copper Nitride for Efficient Ammonia Synthesis.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrocatalytic reduction of nitrate offers a sustainable route for ammonia synthesis.
• Challenges include slow reaction kinetics and competing side reactions.

Purpose of the Study:

• To develop a novel catalyst for efficient and selective electrocatalytic nitrate reduction to ammonia.
• To investigate the role of graphdiyne support in enhancing catalyst performance.

Main Methods:

• Synthesis of copper nitride nanoparticles anchored on graphdiyne (Cu3N/GDY).
• Electrochemical characterization including nitrate reduction reaction (NO3RR) measurements.
• Spectroscopic analysis using electron paramagnetic resonance (EPR) and in situ X-ray absorption fine structure (XAFS).

Main Results:

• The Cu3N/GDY catalyst achieved a high ammonia yield of 35280 μg h-1 mgcat.-1 and a Faradaic efficiency of 98.1% at -0.9 V vs RHE.
• Graphdiyne support facilitated hydrogen absorption and nitrogen vacancy formation in Cu3N, enhancing NO3RR kinetics.
• Distinct absorption sites on GDY and N-vacancies improved selectivity and stability.

Conclusions:

• The Cu3N/GDY catalyst demonstrates significant promise for sustainable ammonia synthesis via electrocatalytic nitrate reduction.
• Graphdiyne is an effective support material for enhancing catalyst performance in NO3RR.
• The study highlights the importance of catalyst design for efficient and selective electrochemical ammonia production.