Boron-Functionalized Organic Framework as a High-Performance Metal-Free Catalyst for N₂ Fixation

Area of Science:

• Materials Science
• Computational Chemistry
• Catalysis

Background:

• Covalent organic frameworks (COFs) offer tunable properties for various applications.
• Nitrogen (N₂) fixation into ammonia (NH₃) is crucial for agriculture and industry.
• Developing efficient, metal-free catalysts for ammonia synthesis remains a significant challenge.

Purpose of the Study:

• To investigate the stability and electronic properties of the two-dimensional TQBQCOF.
• To examine the potential of boron-functionalized TQBQCOF (B/TQBQCOF) for electrocatalytic ammonia synthesis.
• To identify the rate-determining steps and overpotentials for N₂ reduction.

Main Methods:

• First-principles calculations were employed to study TQBQCOF and B/TQBQCOF.
• Mechanical, dynamical, and thermal stability analyses were performed.
• Electrocatalytic pathways for N₂ reduction were investigated using DFT.

Main Results:

• TQBQCOF exhibits excellent mechanical, dynamical, and thermal stability up to 1200 K.
• TQBQCOF is a semiconductor with a direct band gap of 2.70 eV.
• B/TQBQCOF demonstrates low overpotentials for N₂ reduction, with the enzymatic pathway requiring only 0.07 V.

Conclusions:

• B/TQBQCOF is a highly stable and promising metal-free electrocatalyst for ammonia synthesis.
• The low overpotential achieved highlights the potential of TQBQCOF-based materials for sustainable ammonia production.
• This work paves the way for designing novel COF catalysts for energy and environmental applications.