A High-Performance Bimetallic Ru₁Mo₆ Active Site for Thermal Ammonia Synthesis under Mild Conditions

Area of Science:

• Catalysis
• Materials Science
• Chemical Engineering

Background:

• Industrial ammonia synthesis relies on the Haber-Bosch process, demanding high temperatures (430-500 °C) and pressures (10-30 MPa) due to a dissociative N₂ mechanism.
• Nature utilizes an associative mechanism at ambient conditions via nitrogenase's FeMoco active site for ammonia production.

Purpose of the Study:

• To develop a novel catalyst for efficient ammonia (NH₃) synthesis under mild conditions.
• To investigate a Ru₁Mo₆ bimetallic single-cluster active site anchored on Mo₂CT_x MXene for N₂-to-NH₃ conversion.

Main Methods:

• Synthesis of a Ru₁Mo₆ bimetallic single-cluster catalyst anchored on Mo₂CT_x MXene.
• Testing the catalyst's performance for N₂-to-NH₃ thermal synthesis under varying mild conditions (e.g., 50 °C, 0.1 MPa).
• Evaluating long-term stability and ammonia production rates.

Main Results:

• Achieved efficient NH₃ synthesis under mild conditions (50 °C, 0.1 MPa).
• Demonstrated an exceptional NH₃ production rate of 3230 mmol g_Ru^-1 h^-1 at 400 °C and 1 MPa.
• Exhibited >1000 h of long-term stability, surpassing existing Ru catalysts.

Conclusions:

• The novel Ru₁Mo₆ single-cluster catalyst enables efficient and stable ammonia synthesis under mild conditions.
• Atomically precise single-cluster active sites offer a promising strategy for designing advanced catalytic systems.
• This breakthrough could lead to more sustainable and cost-effective industrial ammonia production.