Theoretical Study of the CO₂ Adsorption by Zeolitic Imidazolate Frameworks (ZIFs)

Abstract

Density functional theory with Grimme's empirical correction, DFT-D3, has been used to examine the adsorption of a carbon dioxide molecule by different sets of zeolitic imidazolate framework materials (ZIF-1 to -4, -6 to -10, and -zni). We have calculated the interaction energy, the dipole moment variation, and the charge density difference for the different CO 2 @ZIF structures. Our study shows a strong relationship between the CO 2 adsorption energy and the volume of the cavities of the ZIFs: the capture of carbon dioxide depends on the shape and size of the ZIFs pore in which CO 2 has been inserted. The physisorption phenomena that govern the adsorption of CO 2 molecule require both π-stacking interactions and hydrogen-like bonding. We have found that adsorption does not change the geometry of CO 2 , but it induces a significant structural change in some ZIF structures.

Screening Supported Amine Sorbents in the Context of Post‐combustion Carbon Capture by Vacuum Swing Adsorption

“…Therefore, this requires an adsorbent with a high CO 2 selectivity and capacity. Several adsorbents such as zeolites 10–12, activated carbons 13, 14, metal‐organic frameworks (MOFs) 15, 16 and zeolitic imidazolate frameworks (ZIFs) 17, 18 are currently being explored for post‐combustion CO 2 capture. Amongst these adsorbents, Zeolite 13X is the most widely studied adsorbent due to its commercial availability, low cost and high CO 2 capacity 11, 12.…”

Porous Organic Polymers for CO2 Storage and Conversion Reactions

“…Since the SiÀOÀSi bond angle of zeolites nicely match with the bridging angle of MÀIm-M units (M = metal, Im = imidazolate) in ZIFs, a large spectrum of ZIFs has been reported 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 by varying the metal ions. Through theoretical calculations on interaction energy, dipole moment and the charge density difference, Komiha and co-workers have shown that significant changes occurred at the ZIF surfaces in contact with CO 2 molecules [106] and the shape and size of the ZIFs pores largely facilitate the capture of carbon dioxide. On the other hand polyethyleneimine (PEI) functionalized nanostructured organosilica materials, particularly those bearing low and high molecular weight PEI moieties showed high CO 2 uptakes [107] due to their large surface and available N-sites, which can interact with CO 2 molecules very efficiently.…”

Theoretical studies on carbon dioxide adsorption in cation-exchanged molecular sieves

“…12,13 The adsorption of CO 2 in alkali ion-exchanged zeolites has been extensively investigated experimentally and by computational methods. [6][7][8][9][10][11][12][13][14][15][16][17][18] It was found that the cation-CO 2 geometry is related to the nature of alkali cations on the Y zeolite, where the adsorption enthalpies show a decrease from Li + to Cs 7+ . Yang et al found that the samples of Cs@RWY, Rb@RWY, and K@RWY exhibited excellent CO 2 adsorption properties.…”

“…17 A strong relationship between the CO 2 adsorption energy and the volume of the cavities of the zeolitic imidazolate framework materials was also found. 18 However, there is a scarcity of systematic study on interactions between molecular sieves and CO 2 , such as the effect of the zeolite topology and alkali-metal cation type on CO 2 adsorption. In this work, the adsorption structure and energies of carbon dioxide on different metal cation-exchanged zeolites were well investigated, aiming to provide a theoretical understanding of the CO 2 adsorption, and help the optimal design of suitable molecular sieves in the experiment.…”