Prediction of CO₂ Adsorption Properties in Zeolites Using Force Fields Derived from Periodic Dispersion-Corrected DFT Calculations

Abstract

We demonstrate a new approach to develop transferable force fields describing molecular adsorption in zeolites by combining dispersion-corrected density functional theory (DFT) calculations and classical atomistic simulations. This approach is illustrated with the adsorption of CO 2 in zeolites. Multiple dispersion-corrected DFT methods were tested for describing CO 2 adsorption in sodium-exchanged ferrierite. The DFT-D2 approach was found to give the best agreement with high level quantum chemistry results and experimental data. A classical force field for CO 2 adsorption in siliceous zeolites was then developed on the basis of hundreds of DFT-D2 calculations that probed the full range of accessible volume in purely siliceous chabazite (Si-CHA) via random sampling. We independently performed experiments with Si-CHA measuring CO 2 isotherms and heats of adsorption by microcalorimetry. Excellent agreement was obtained between adsorption isotherms predicted with our first-principles-derived force field and our experiments. The transferability of this force field was examined using available adsorption isotherms for CO 2 in siliceous MFI and DDR zeolites, again with reasonably good agreement between calculated and experimental results. The methods demonstrated by these calculations will be broadly applicable in using molecular simulations to predict properties of adsorbed molecules in zeolites and other nanoporous materials.

New materials for methane capture from dilute and medium-concentration sources

“…The results immediately reveal an IZA structure, SBN, that stands out in its performance-roughly 2.75 (mol kg À 1 ) adsorbed CH 4 and 45% adsorbed CH 4 concentration. We also utilized the recently published force field D2FF, which is developed based on dispersion-corrected density functional theory (DFT), from Sholl and co-workers 23 to compute the SBN CO 2 adsorption isotherms. Adsorption isotherms calculated via D2FF have been shown to accurately reproduce the experimental isotherms for CHA, MFI and DDR silicate zeolite structures 23 .…”

“…We also utilized the recently published force field D2FF, which is developed based on dispersion-corrected density functional theory (DFT), from Sholl and co-workers 23 to compute the SBN CO 2 adsorption isotherms. Adsorption isotherms calculated via D2FF have been shown to accurately reproduce the experimental isotherms for CHA, MFI and DDR silicate zeolite structures 23 . In our work, the SBN CO 2 isotherms obtained from D2FF predict even better overall performance (see Fig.…”

Transferable force-field for modelling of CO2, N2, O2and Ar in all silica and Na+exchanged zeolites

“…The adsorption isotherms are in this case measured in a wider range of temperatures from 273 up to a 343 K. In this example our force field tends to underestimate adsorption loading at higher temperatures. Note however some differences between experimental data of works [61] and [41] for the same CHA structure at 301 and 303K.…”

Force-Field Development from Electronic Structure Calculations with Periodic Boundary Conditions: Applications to Gaseous Adsorption and Transport in Metal–Organic Frameworks

“…Fang et al proposed a methodology to obtain force fields from dispersion-corrected density functional theory (DFT) calculations, and the method accurately predicts the CO 2 adsorption isotherms inside zeolites. 14 In their approach, two global scaling factors were added to the classical 12−6 Lennard-Jones potential, and these parameters were optimized using about one thousand singlepoint DFT calculations. Zang et al used this method to study H 2 O inside CuBTC, which also possesses open-metal sites.…”