Isosteric heat of adsorption is indispensable in probing the energetic behavior of interaction between adsorbate and solid, and it can shed insight into how molecules interact with a solid by studying the dependence of isosteric heat on loading. In this study, we illustrated how this can be used to explain the difference between adsorption of non-polar (and weakly polar) fluids and strong polar fluids on a highly graphitized carbon black, Carbopack F. This carbon black has a very small quantity of functional group, and interestingly we showed that no matter how small it is the analysis of the isosteric heat versus loading can identify its presence and how it affects the way polar molecules adsorb. We used argon and nitrogen as representatives of non-polar fluid and weakly polar fluid, and methanol and water for strong polar fluid. The pattern of the isosteric heat versus loading can be regarded as a fingerprint to determine the mechanism of adsorption for strong polar fluids, which is very distinct from that for non-polar fluids. This also allows us to estimate the interplay between the various interactions: fluid-fluid, fluid-basal plane and fluid-functional group.
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http://dx.doi.org/10.1016/j.jcis.2014.10.024 | DOI Listing |
J Phys Chem B
January 2025
Department of Mathematics and Physics, North China Electric Power University, Baoding 071003, China.
Within the framework of classical density functional theory, the isosteric heat and condensation/evaporation heat of the confined methane are studied. First, the theoretical expression for condensation/evaporation heat is derived on the basis of the first law of thermodynamics. The method for computation is also proposed.
View Article and Find Full Text PDFSci Rep
January 2025
Thermodynamics Research Laboratory, School of Chemical Engineering, Iran University of Science and Technology, Tehran, 16846-13114, Iran.
This study investigates the pyrolysis mechanism of cellulose using reactive molecular dynamics simulations to prepare biochars for CO separation applications. Six biochars with densities ranging from 0.160 to 0.
View Article and Find Full Text PDFChemistry
January 2025
Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, College of Chemistry and Materials Sciences, Zhejiang Normal University, Jinhua, 321004, P. R. China.
The advancement of high-value CH purification technology within the natural gas industry is paramount for industrial processes. Herein, we constructed ZJNU-402, a new porous material characterized by permanent porosity, as an effective adsorbent for separating CH/CH and CH/CH mixtures. The findings reveal an outstanding CH adsorption capacity of 68 cm g and a moderate CH adsorption rate of 42 cm g, with a notably lower CH adsorption rate of 11 cm g.
View Article and Find Full Text PDFChem Asian J
January 2025
Institute of Clinical Pharmacy and Pharmaceutical Sciences, School of Pharmacy, College of Medicine, National Cheng Kung University, Tainan City, 70101, Taiwan.
We report three novel pore-space-partitioned metal-organic frameworks (MOFs) functionalized with fluorine and hydroxyl groups using 2,3,5,6-tetrafluorobenzene-1,4-dicarboxylic acid (F-BDC) and a new ligand 3,6-difluoro-2,5-dihydroxybenzene-1,4-dicarboxylic acid (F(OH)-BDC) as organic building blocks, with 1,3,5-tris(4-pyridyl)-2,4,6-triazine (TPT) as pore partition agent. With the polar fluorine and hydroxyl groups and the open metal sites being blocked by TPT, moderate molecule-framework interactions can be engineered. These three isoreticular microporous frameworks Mn-TPT-BDC-F (NCKU-21), Mn-TPT-BDC-F(OH) (NCKU-22), and Mg-TPT-BDC-F(OH) (NCKU-23) (NCKU=National Cheng Kung University) exhibit distinct single-component gas adsorption behaviors.
View Article and Find Full Text PDFJACS Au
December 2024
Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, Pennsylvania 18015, United States.
Understanding the origin and effect of the confinement of molecules and transition states within the micropores of a zeolite can enable targeted design of such materials for catalysis, gas storage, and membrane-based separations. Linear correlations of the thermodynamic parameters of molecular adsorption in zeolites have been proposed; however, their generalizability across diverse molecular classes and zeolite structures has not been established. Here, using molecular simulations of >3500 combinations of adsorbates and zeolites, we show that linear trends hold in many cases; however, they collapse for highly confined systems.
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