Graphdiyne coordinated transition metals as single-atom catalysts for nitrogen fixation

Area of Science:

• Catalysis
• Materials Science
• Computational Chemistry

Background:

• Nitrogen reduction to ammonia (NH3) is crucial but challenging.
• Electrocatalytic nitrogen reduction reaction (NRR) offers a sustainable NH3 synthesis pathway.
• Developing efficient single-atom catalysts (SACs) is key for NRR.

Purpose of the Study:

• To design and investigate a new class of single-atom catalysts (SACs) based on graphdiyne coordinated transition metal atoms (TM@GDY).
• To systematically evaluate the NRR catalytic performance of TM@GDY monolayers.
• To identify potential descriptors for NRR activity and guide future catalyst development.

Main Methods:

• First-principles calculations were employed to design and study TM@GDY catalysts.
• The NRR catalytic character of various TM@GDY configurations was systematically investigated.
• The relationship between limiting potential and N adsorption energy was analyzed.

Main Results:

• Several TM@GDY monolayers (e.g., Ti, V, Fe, Co, Zr, Rh, Hf) demonstrated superior NRR activity compared to Ru(0001).
• A linear correlation was found between limiting potential and atomic N adsorption energy, identifying it as a potential descriptor.
• The V@GDY monolayer exhibited the best NRR performance with a limiting potential of -0.67 V, with the N2→NNH step being rate-limiting.

Conclusions:

• A new family of efficient and stable TM@GDY catalysts for NRR was identified.
• Atomic N adsorption energy serves as a reliable descriptor for NRR catalytic performance.
• These findings provide valuable guidelines for the development and application of SACs in electrocatalytic ammonia synthesis.