Hydrophobic Nanoporous Silver with ZIF Encapsulation for Nitrogen Reduction Electrocatalysis

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Ammonia production relies heavily on the energy-intensive Haber-Bosch process.
• Electrochemical nitrogen reduction reaction (ENRR) presents a sustainable alternative but faces challenges like low yields and competing hydrogen evolution.
• Existing catalysts often lack sufficient active sites and selectivity.

Purpose of the Study:

• To develop a high-performance catalyst for ENRR.
• To enhance ammonia yield and Faradaic efficiency.
• To suppress the hydrogen evolution reaction during ENRR.

Main Methods:

• Design and synthesis of a hydrophobic oleylamine-modified zeolitic imidazolate framework-coated nanoporous silver composite (NPS@O-ZIF).
• Characterization of the catalyst's structure and properties.
• Electrochemical testing of the catalyst for ENRR performance evaluation.

Main Results:

• The NPS@O-ZIF composite achieved a high ammonia yield of (41.3 ± 0.9) μg·h^-1·cm^-2.
• A Faradaic efficiency of (31.7 ± 1.2)% was obtained, outperforming control catalysts.
• The hydrophobic coating effectively suppressed hydrogen evolution.

Conclusions:

• The developed hydrophobic core-shell composite catalyst significantly improves ENRR performance.
• This strategy offers a practical approach for efficient ammonia synthesis via ENRR.
• The catalyst design is valuable for other water-sensitive electrochemical reactions.