BaSiN2:O Electrene Catalyst Achieves Ammonia Synthesis Under Mild Conditions

Researchers at the Institute of Science Tokyo have developed an innovative surface electrene, BaSiN₂:O, that enables efficient ammonia synthesis under mild conditions. This breakthrough was reported on July 13, 2026, and represents a significant advancement in the field of sustainable chemical production.

Key Features of BaSiN2:O Electrene

The newly synthesized BaSiN₂:O electrene is notable for its air stability, a characteristic that has long hindered the practical use of electrenes in various chemical reactions. By introducing a small amount of oxygen into barium silicon nitride, the research team created a stable layer of freely floating electrons on the electrene's surface. This innovative structure gives the material an ultralow work function of approximately 1.5 eV, facilitating efficient electron donation.

Professor Hideo Hosono, who led the research team, stated, "To the best of our knowledge, BaSiN₂:O represents the first-ever example of an air-stable surface electrene. It opens a new pathway towards highly efficient and robust catalysts for sustainable ammonia production..." This stability allows the electrene to maintain its catalytic performance even after a week of exposure to air.

How the Catalyst Works

The BaSiN₂:O electrene employs a self-protecting mechanism when exposed to nitrogen gas. Its surface electrons spontaneously transfer to N₂ molecules, forming a chemically adsorbed nitrogen layer that coats and protects the surface. This passivation layer enhances the material's resistance to air, enabling it to function effectively in less-than-ideal environments.

When the material is treated with hydrogen, the activated nitrogen is converted back into ammonia, allowing the process to repeat without degrading the catalyst. The researchers found that the addition of ruthenium (Ru) nanoparticles significantly enhances the catalyst's ability to activate hydrogen, further improving ammonia synthesis efficiency.

Performance and Implications for Sustainable Ammonia Production

The Ru/BaSiN₂:O catalyst achieved an impressive ammonia synthesis rate of 43 mmol g^-1 h^-1 at 300 °C and 0.9 MPa. This performance surpasses previously reported electride, hydride, and conventional Ru-based catalysts operating under similar low-temperature conditions.

The stability of the material is also noteworthy, as it retains its crystal structure and catalytic activity even after repeated cycles of air exposure. This finding suggests a promising future for electrenes in practical applications across chemistry, energy, and electronics.

• Ammonia synthesis rate: 43 mmol g^-1 h^-1
• Temperature: 300 °C
• Pressure: 0.9 MPa
• Air exposure stability: 1 week

In conclusion, the research conducted by the team at the Institute of Science Tokyo not only identifies a new type of air-stable electrene but also paves the way for the efficient synthesis of green ammonia at lower temperatures and pressures.