02601nas a2200241   4500008004100000022001400041245018300055210006900238260000800307300001100315490000800326520170900334653002002043653002502063653002702088653002102115653001302136100002002149700001602169700001802185700002602203856013002229       2023                        eng d  a1387-181100aInsights into adsorption of various gases on extra-framework cations of zeolite: a dispersion corrected DFT study on zeolite cluster models with Li plus , Na plus and K plus ions0 aInsights into adsorption of various gases on extraframework cati  cNov  a1127390 v3613 a<p>
	Design of an economical and sustainable gas separation material is relevant in several industrial processes. Zeolites with tunable pore sizes are ideal molecular sieves of many gases. The adsorption centers of these molecular sieves are extra-framework Lewis acid centers. In this study, we attempt to delineate the electronic properties of such centers (Li+, Na+ and K+) and their sorption properties towards N2, O2, CO, CO2 and H2. Negative framework of zeolites are modeled using different cluster models that present distinct electronic environment and role of this environment on the Lewis acidity of the cation. The sorption property towards different gases is evaluated using dispersion corrected DFT studies. The results obtained are benchmarked for one of the studied model using CCSD calculations. The results indicate that while the local environment modulates the adsorption properties, the relative adsorption properties between different ions follow the same order irrespective of the type of negative framework modeled. This reveals that intrinsic atomic properties of the charge compensating cations drive the sorption properties of the zeolites. Adsorption energies compounded with the analysis of IR stretching frequencies of the adsorbed gases reveals that Li centers shows molecular adsorption (charge donation to the cationic centers) towards N2 as compared to O2 and towards CO2/CO as compared to H2, demonstrating the applicability of Li-Zeolites as ideal membranes for oxygen concentrators and syngas separation. These adsorption studies are ratified by the BOMD simulations at 300 K, where H2 and O2 desorbs while N2, CO and CO2 remains adsorbed to the cationic site.</p>
10aBOMD simulation10aCO/CO2/H2 separation10aExtra-framework cation10aN2/O2 separation10azeolites1 aDevasia, George1 aKumar, Ravi1 aVaval, Nayana1 aKrishnamurty, Sailaja  uhttps://library.ncl.res.in/content/insights-adsorption-various-gases-extra-framework-cations-zeolite-dispersion-corrected-dft