First principles derived, transferable force fields for CO2 adsorption in Na-exchanged cationic zeolites.

Area of Science:

• Materials Science
• Computational Chemistry
• Chemical Engineering

Background:

• Accurate force fields are essential for predicting gas adsorption in porous materials like zeolites.
• Previous work established a transferable force field for CO2 adsorption in siliceous zeolites.

Purpose of the Study:

• To extend first-principles-based force field development for carbon dioxide (CO2) adsorption to complex cationic zeolites.
• To investigate the influence of computational methods on force field accuracy for CO2-zeolite interactions.

Main Methods:

• Development of transferable force fields using first-principles calculations.
• Application to CO2 adsorption in Na-exchanged zeolites (LTA-4A, NaX, NaY).
• Validation of simulation results against experimental adsorption isotherms and microcalorimetric heats.

Main Results:

• The PBE-D2 derived force field overestimated CO2 adsorption in cationic zeolites due to issues with multi-cation sites.
• A force field derived from the DFT/CC method demonstrated good performance for CO2 adsorption in Na-exchanged zeolites.
• The DFT/CC derived force field showed agreement with experimental data for LTA-4A, NaX, and NaY zeolites.

Conclusions:

• The choice of first-principles method significantly impacts force field accuracy for CO2 adsorption in cationic zeolites.
• The DFT/CC method provides a reliable approach for developing accurate force fields for CO2 adsorption in complex zeolite structures.
• This work enables more precise prediction of CO2 adsorption in industrially relevant cationic zeolites.