Rational Design of Covalent Organic Frameworks-Based Single Atom Catalysts for Oxygen Evolution Reaction and Oxygen...

Area of Science:

• Materials Science
• Electrochemistry
• Computational Chemistry

Background:

• Developing efficient catalysts for oxygen evolution (OER) and oxygen reduction (ORR) is crucial for renewable energy technologies like fuel cells and metal-air batteries.
• Two-dimensional covalent organic frameworks (2D COFs) offer unique hollow sites ideal for anchoring transition metal atoms, creating promising single-atom catalysts (SACs).

Purpose of the Study:

• To systematically investigate the OER and ORR catalytic performance of SACs supported by TQBQ-COFs.
• To understand the influence of the coordination environment on catalytic activity.
• To identify effective descriptors for designing high-performance SACs.

Main Methods:

• Density functional theory (DFT) calculations were employed to study a series of SACs based on TQBQ-COFs.
• Catalytic performance for OER and ORR was evaluated.
• The role of coordination environment and adsorption energetics was analyzed.

Main Results:

• Rh/TQBQ demonstrated the most effective OER performance with a low overpotential of 0.34 V.
• Au/TQBQ showed superior ORR performance with an overpotential of 0.50 V.
• Boundary oxygen atoms in TQBQ were found to uniquely influence reaction pathways, bypassing conventional scaling relationships.

Conclusions:

• The coordination environment significantly impacts catalyst performance for OER and ORR.
• Adsorption energy of transition metal atoms (Ead) serves as a reliable descriptor for predicting catalytic activity.
• This work provides a new approach for designing novel and efficient COF-based SACs for OER/ORR applications.