Ligand engineering towards electrocatalytic urea synthesis on a molecular catalyst

Area of Science:

• Electrochemistry
• Materials Science
• Sustainable Chemistry

Background:

• Conventional urea synthesis is energy-intensive.
• Electrocatalytic C-N coupling offers a sustainable alternative for waste upgrading.
• Developing efficient and stable electrocatalysts is crucial for urea synthesis.

Purpose of the Study:

• To investigate amino-substituted copper phthalocyanine (CuPc-Amino) as a novel electrocatalyst for urea synthesis.
• To enhance catalyst activity and stability through electronic structure optimization.
• To elucidate the reaction mechanism of electrocatalytic C-N coupling.

Main Methods:

• Experimental synthesis and characterization of CuPc-Amino.
• Computational studies to understand electronic structure and bonding.
• Electrochemical performance testing (yield rate, durability).
• Isotope-labeling operando electrochemical spectroscopy for mechanism studies.

Main Results:

• CuPc-Amino exhibits significantly higher urea yield rate (103.1 ± 5.3 mmol h⁻¹ g⁻¹) compared to CuPc (39.9 ± 1.9 mmol h⁻¹ g⁻¹).
• Amino substitution strengthens Cu-N coordination and suppresses demetallation, enhancing stability.
• Electrochemical measurements validated the C-N coupling process and reaction mechanism.

Conclusions:

• Amino substitution is an effective strategy for designing high-performance molecular electrocatalysts for urea synthesis.
• CuPc-Amino demonstrates superior activity and durability, offering a promising pathway for sustainable urea production.
• This work provides a rational design scheme for advanced electrocatalysts.