High energy density mixed polymeric phase from carbon monoxide and nitrogen

Area of Science:

• Materials Science
• High-Pressure Physics
• Computational Chemistry

Background:

• Carbon monoxide (CO) and nitrogen (N2) are high-energy density material candidates.
• These molecules exhibit distinct behaviors under high pressure despite physical similarities.

Purpose of the Study:

• Investigate the formation of novel mixed crystalline phases between CO and N2.
• Explore their properties under high pressures up to 100 GPa.

Main Methods:

• Density functional theory (DFT) calculations.
• Ab initio structural prediction methods.

Main Results:

• CO catalyzes N2 molecular dissociation, favoring mixed structures below 18 GPa.
• A stable 3D framework (Pbam symmetry) identified as the most stable phase above 52 GPa.
• This phase is dynamically stable at ambient pressure with an energy density of ~2.2 kJ/g.

Conclusions:

• Mixed CO-N2 phases can be formed under relatively mild high-pressure conditions.
• The identified 3D framework is a promising candidate for high-energy density materials.
• Achievable experimental conditions make this material attractive for further research.