02600nas a2200241   4500008004100000022001400041245018300055210006900238260000800307300001100315490000800326520170900334653002002043653002502063653002702088653002102115653001302136100002002149700001602169700001802185700002602203856012902229       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  uhttp://library.ncl.res.in/content/insights-adsorption-various-gases-extra-framework-cations-zeolite-dispersion-corrected-dft00912nas a2200241   4500008004100000022001400041245014900055210006900204260001100273300001600284490000700300100001800307700002300325700002000348700002600368700001700394700001600411700002900427700002500456700002800481700003000509856013100539       2024                        eng d  a2041-652000aScalable approach using a gC3N4 -covalent organic framework hybrid catalyst towards sustainable hydrogen production from seawater and wastewater0 aScalable approach using a gC3N4 covalent organic framework hybri  cAUG 22  a13381-133880 v151 aAsokan, Kiran1 aBhagyasree, T., M.1 aDevasia, George1 aKrishnamurty, Sailaja1 aSolim, Sabah1 aRueda, Lina1 aAl-Mohannadi, Dhabia, M.1 aAl-Hashimi, Mohammed1 aKakosimos, Konstantinos1 aBabu, Sukumaran, Santhosh  uhttp://library.ncl.res.in/content/scalable-approach-using-gc3n4-covalent-organic-framework-hybrid-catalyst-towards-sustainable02267nas a2200169   4500008004100000022001400041245015900055210006900214260000900283300001400292490000700306520158300313100002001896700002601916700002601942856012901968       2025                        eng d  a1463-907600aEvaluating the preferential adsorption of N2 from a binary mixture of N2/O2 on extra-framework cations of zeolites: a computational and experimental study0 aEvaluating the preferential adsorption of N2 from a binary mixtu  cAPR   a7846-78570 v273 a<p>
	Separation of N2 from a N2/O2 gas mixture is critical for various industrial/medical applications. Temperature/pressure swing adsorption is the top-notch industrial technology used for this separation, where zeolites are the materials used for adsorption. Zeolite X/Y with Li+ as an extra-framework cation is the best-known sorbent for N2 gas molecules. However, the present net zero emission scenario has made lithium a critical element, making it imperative to implement its alternative in various other technologies. In this context, the present work is a computational evaluation to identify a cation that can replace Li+ for preferential adsorption of N2 over O2. The DFT study, based on parameters such as selective adsorption energies of N2 over O2 and IR stretching frequencies of the adsorbed N2 and O2 molecules, identifies Mg2+, Ca2+, Sr2+, Co2+ and Zn2+ as potential cations. These cations have preferential adsorption for N2 over O2 by 10 kJ mol-1 or more. However, BOMD simulations reveal that only Mg2+, Ca2+, Co2+ and Zn2+ keep the N2 molecule bound at 300 K and the O2 molecule gets desorbed from these frameworks. The desorption temperature of N2 on Ca2+ and Zn2+ is 350 K and on Mg2+ is 400 K. These observations are corroborated by electronic charges on cations and molecular orbitals. Significantly, Ca2+ is identified to adsorb up to 2 N2 molecules, making it an ideal candidate for N2/O2 separation in place of Li+. To validate this, we have carried out an experimental study that showed a good N2 adsorption capacity of 2.1 mmol g-1 for Ca2+.</p>
1 aDevasia, George1 aNandanwar, Sachin, U.1 aKrishnamurty, Sailaja  uhttp://library.ncl.res.in/content/evaluating-preferential-adsorption-n2-binary-mixture-n2o2-extra-framework-cations-zeolites