Ab initio carbon capture in open-site metal-organic frameworks

Area of Science:

• Materials Science
• Computational Chemistry
• Chemical Engineering

Background:

• Metal-organic frameworks (MOFs) can contain open metal sites after solvent removal, which strongly adsorb CO2.
• Existing force fields inaccurately predict CO2 adsorption in Mg-MOF-74, underestimating it by orders of magnitude.
• Understanding CO2 interactions with these open sites is crucial for effective carbon capture technologies.

Purpose of the Study:

• To develop accurate force fields for simulating CO2 adsorption in Mg-MOF-74.
• To elucidate the interactions between CO2 and open metal sites in Mg-MOF-74.
• To improve the reliability of molecular simulations for MOF-based carbon capture.

Main Methods:

• Generating force fields using high-level quantum chemical calculations.
• Performing Monte Carlo simulations with an ab initio force field for CO2 in Mg-MOF-74.
• Validating the force field against thermodynamic data from flue gas.

Main Results:

• The developed force field accurately describes the chemistry of open metal sites in Mg-MOF-74.
• Simulations provide insights into the interpretation of thermodynamic data for CO2 capture.
• The force field demonstrates transferability to other MOF structures.

Conclusions:

• Accurate force fields are essential for reliable molecular simulations of CO2 capture in MOFs.
• This approach enhances the understanding of fluid-solid interactions in porous materials.
• The methodology can be applied broadly to molecular simulations and materials design for gas adsorption.