Two-Dimensional Single-Atom Catalyst TM₃(HAB)₂ Monolayers for Electrocatalytic Dinitrogen Reduction Using...

Area of Science:

• Materials Science
• Catalysis
• Electrochemistry
• Computational Chemistry

Background:

• The electrocatalytic nitrogen reduction reaction (eNRR) is a sustainable strategy for ammonia production.
• Current eNRR catalysts face challenges of low conversion rates and high overpotentials.
• Efficient catalysts are crucial for advancing sustainable ammonia synthesis.

Purpose of the Study:

• To screen and identify efficient two-dimensional metal-organic layer (MOL) catalysts for eNRR.
• To evaluate transition metal-embedded MOLs (TM3(HAB)2) using high-throughput screening and DFT.
• To discover novel catalysts for sustainable ammonia synthesis.

Main Methods:

• A three-step high-throughput screening approach was employed.
• Spin-polarized density functional theory (DFT) calculations were utilized.
• Catalyst performance, including onset potential, free energy, conductivity, stability, and selectivity, was computed.

Main Results:

• Nb3(HAB)2, Mo3(HAB)2, and Tc3(HAB)2 were identified as eligible NRR candidates.
• Tc3(HAB)2 demonstrated superior performance with a -0.63 V onset potential and 0.22 eV NH3 desorption energy.
• Tc3(HAB)2 and Nb3(HAB)2 exhibit good conductivity, stability, and selectivity for NRR, while Mo3(HAB)2 is limited by HER.

Conclusions:

• Tc3(HAB)2 and Nb3(HAB)2 monolayers are promising catalysts for efficient and selective nitrogen fixation.
• The study provides insights into the electronic structure and orbital hybridization responsible for high catalytic activity.
• This work expands the scope of single-atom catalysts on MOLs for nitrogen reduction.