Capturing Copper Single Atom in Proton Donor Stimulated O-End Nitrate Reduction.

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Ammonia (NH3) is crucial for global production and energy cycles.
• Electrocatalytic nitrate reduction (e-NO3RR) is a promising but challenging method for NH3 synthesis.
• Existing methods face issues with competing reactions and low catalyst activity.

Purpose of the Study:

• To develop a novel catalyst and mechanism for efficient electrocatalytic nitrate reduction (e-NO3RR) to ammonia (NH3).
• To address limitations of competing reactions and low catalyst activity in NH3 synthesis.
• To explore the role of proton donors in mediating the O-end e-NO3RR pathway.

Main Methods:

• Developed a novel catalyst (p-CNCu^sLa^n-m) by embedding Cu single atoms on La-based nanoparticles using UV reduction, confined synthesis, and microwave treatment.
• Utilized Density Functional Theory (DFT) analysis to investigate the role of La-based clusters as proton donors.
• Employed in situ characterization to reveal the O-end adsorption reduction mechanism.

Main Results:

• Achieved a high Faraday efficiency (FE_NH3) of 97.7% for NH3 production.
• Demonstrated a high NH3 production rate of 10.6 mol g_metal^-1 h^-1.
• Exhibited excellent stability in a flow cell, with only a 9% current density decrease after 111 hours and a NH3 production rate of 1.57 mg_NH3/h/cm^-2.

Conclusions:

• The synergistic proton donor mechanism significantly enhances e-NO3RR for efficient NH3 synthesis.
• The novel catalyst and O-end mechanism offer a pathway for advanced electrocatalyst design.
• This work opens new avenues for molecular-oriented coupling reactions and electrochemical synthesis applications.