Single Mo Atom Supported on Defective Boron Nitride Monolayer as an Efficient Electrocatalyst for Nitrogen Fixation:...

Area of Science:

• Catalysis
• Materials Science
• Electrochemistry

Background:

• Ammonia (NH3) synthesis from dinitrogen (N2) under mild conditions is a significant challenge in chemistry.
• Electrocatalytic nitrogen fixation offers a sustainable alternative to the Haber-Bosch process.
• Defective boron nitride (BN) materials are emerging as promising catalyst supports.

Purpose of the Study:

• To investigate single transition metal atoms supported on defective BN monolayers as electrocatalysts for N2 fixation.
• To identify the most active single-atom catalyst for ammonia synthesis under ambient conditions.
• To elucidate the mechanism and key factors governing the catalytic activity.

Main Methods:

• Density Functional Theory (DFT) computations were employed to systematically screen transition metal catalysts.
• Calculations focused on single transition metal atoms (Sc-Zn, Mo, Ru, Rh, Pd, Ag) supported on a BN monolayer with a boron monovacancy.
• Reaction pathways and overpotentials for N2 reduction were analyzed.

Main Results:

• The single molybdenum (Mo) atom supported on a defective BN nanosheet demonstrated the highest catalytic activity.
• This Mo-based catalyst achieved N2 fixation at room temperature with a low overpotential of 0.19 V.
• The mechanism involves selective stabilization of N2H* and destabilization of NH2* intermediates.

Conclusions:

• Single-atom catalysts, specifically Mo on defective BN, show great promise for efficient ammonia production.
• This approach offers a new pathway for sustainable ammonia synthesis under ambient conditions.
• The findings pave the way for developing novel single-atom electrocatalysts for N2 fixation.