IAST

Development of crystalline porous materials for selective CO2 adsorption and storage is in high demand to boost the carbon capture and storage (CCS) technology. In this regard, we have developed a β-keto enamine-based covalent organic framework ( VM-COF ) via the Schiff base polycondensation technique. The as-synthesized VM-COF exhibited excellent thermal and chemical stability along with a very high surface area (1258 m2 g-1 ) and a high CO2 adsorption capacity (3.58 mmol g-1 ) at room temperature (298 K)...

In the present work, three novel halogen-appended cadmium(II) metal-organic frameworks [Cd2 (L1)2 (4,4'-Bipy)2 ] n ·4 n (DMF) ( 1 ), [Cd2 (L2)2 (4,4'-Bipy)2 ] n ·3 n (DMF) ( 2 ), and [Cd(L3)(4,4'-Bipy)] n ·2 n (DMF) ( 3 ) [where L1 = 5-{(4-bromobenzyl)amino}isophthalate; L2 = 5-{(4-chlorobenzyl)amino}isophthalate; L3 = 5-{(4-fluorobenzyl)amino}isophthalate; 4,4'-Bipy = 4,4'-bipyridine; and DMF = N , N '-dimethylformamide] have been synthesized under solvothermal conditions and characterized by various analytical techniques...

Obtaining suitable adsorbents for selective separation of SO2 from flue gas still remains an important issue. A stable Zr(IV)-MOF (Zr-PTBA) can be conveniently synthesized through the self-assembly of a tetracarboxylic acid ligand (H4 L = 4,4',4'',4'''-(1,4-phenylenebis(azanetriyl))tetrabenzoic acid) and ZrCl4 in the presence of trace water. It exhibits a three-dimensional porous structure. The BET surface area is 1112.72 m2 /g and the average pore size distribution focus on 5.9, 8.0 and 9.3 Å...

The separation of acetylene from carbon dioxide is challenging due to their almost identical molecular sizes and volatilities. Metal-organic frameworks (MOFs) in general are strong candidates for the separation of gas mixtures owing to the presence of functional pore surfaces that can selectively capture specific target molecules. Herein, we report a stable and easily synthesized bismuth-based MOF, Bi-BTC, which can achieve the separation of acetylene and carbon dioxide. We performed a detailed analysis of the sorption properties of the Bi-MOF...

CONTEXT: MOFs are promising candidates for the capture of H2 S and CO2 from raw biogas. The presence of H2 S residues in natural gas pipelines can cause corrosive damage and reduce energy efficiency. H2 S capture from biogas presents several challenges due to its high toxicity and its corrosiveness. Microporous MOFs incorporating Lewis basic sites have demonstrated efficient capture of small and polar gas molecules such as CO2 and H2 S from gas binary mixtures. In the quest to design and investigate functional materials to support the energy transition, specifically for the purification of RNG gas, we theoretically investigated the potential of s-heptazine-based IRH-1 for H2 S capture from CH4 mixtures...

One-step efficient separation of high-purity C2H4 from C2H4 / C2H6 mixtures by HOFs faces two problems: lack of strategies for constructing stable pores in HOFs and how to obtain high C2H6 selectivity. Herein, we have developed a microporous Mortise-Tenon-type HOF (MTHOF-1, MT is short for Mortise-Tenon structure) with a new self-assembly mode for C2H4 / C2H6 separation. Unlike previous HOFs which usually possess discrete head-to-head hydrogen bonds, MTHOF-1 is assembled by a unique consecutive side-by-side hydrogen bonds, which result in mortise-and-tenon pores decorated with orderly arranged amide groups and benzene rings...

Developing reliable solid sorbents for efficient capture and removal of trace sulfur dioxide (SO2 ) under ambient conditions is critical for industrial desulfurization operations, but poses a great challenge. Herein, we focus on SNFSIX-Cu-TPA, a highly stable fluorinated MOF that utilizes SnF6 2- as pillars, for effectively capturing SO2 at extremely low pressures. The exceptional affinity of SNFSIX-Cu-TPA towards SO2 over CO2 and N2 was demonstrated through single-component isotherms and corroborated by computational simulations...

Adsorption isotherms of pure vapors and vapor mixtures of water, methanol, and cyclohexane were studied using a synthesized 13X zeolite (FAU topology), by means of a DVS gravimetric vapor analyzer. These results were validated by GCMC calculations. The surface chemistry of the adsorbent was characterized by the thermodesorption of ammonia, and its textural properties were studied using nitrogen physisorption. The 13X zeolite was found to be strongly acidic (BrØnsted acid sites, Si/Al = 1.3) and its specific surface area around 1100 m2 ·g-1 ...

Fluoro- and chlorofluorocabons (FC/CFCs) are important refrigerants, solvents, and fluoropolymers in industry while being toxic and carrying high global warming potential. Detection and reclamation of FC/CFCs based on adsorption technology with highly selective adsorbents is important to labor safety and environmental protection. Herein, the study reports an integrated method to combine capture, separation, enrichment, and analysis of representative FC/CFCs (chlorodifluoromethane(R22) and 1,1,1,2-tetrafluoroethane (R134a)) by using the highly stable and porous Zr-MOF, DUT-67...

Capturing and separating carbon dioxide, particularly using porous carbon adsorption separation technology, has received considerable research attention due to its advantages such as low cost and ease of regeneration. In this study, we successfully developed a one-step carbonization activation method using freeze-thaw pre-mix treatment to prepare high-nitrogen-content microporous nitrogen-doped carbon materials. These materials hold promise for capturing and separating CO2 from complex gas mixtures, such as biogas...

Rational design of organic building blocks provides opportunities to control and tune various physicochemical properties of metal-organic frameworks (MOFs), including gas handling, proton conduction, and structural flexibility, the latter of which is responsible for new adsorption phenomena and often superior properties compared to rigid porous materials. In this work, we report synthesis, crystal structures, gas adsorption, and proton conduction for a flexible two-dimensional cadmium-based MOF ( JUK-13-SO3H-SO2 ) containing a new sulfonated 4,4'-oxybis(benzoate) linker with a blocking SO2 bridge...

Comprehensive understanding of substituent groups located on the pore surface of metal-organic frameworks (which we call substituent engineering herein) can help to promote gas adsorption and catalytic performance through ligand functionalization. In this work, pore-space-partitioned metal-organic frameworks (PSP MOFs) were selected as a platform to evaluate the effect of organic functional groups on CO2 adsorption, separation, and catalytic conversion. Twelve partitioned acs metal-organic frameworks (pacs-MOFs, named SNNU-25-R n here) containing different functional groups were synthesized, which can be classified into electron-donor groups (-OH, -NH2 , -CH3 , and -OCH3 ) and electron-acceptor groups (-NO2 , -F, -Cl, and -Br)...

The excessive release of greenhouse gases, especially carbon dioxide (CO2 ) pollution, has resulted in significant environmental problems all over the world. CO2 capture technologies offer a very effective means of combating global warming, climate change, and promoting sustainable economic growth. In this work, UiO-66-NH2 was synthesized by the novel sonochemical method in only one hour. This material was characterized through PXRD, FT-IR, FE-SEM, EDX, BET, and TGA methods. The CO2 capture potential of the presented material was investigated through the analysis of gas isotherms under varying pressure conditions, encompassing both low and high-pressure regions...

Covalent organic frameworks (COFs) are a promising class of adsorption and separation materials that can meet the needs of ecological sustainability, such as the removal of carbon dioxide and organic dyes. The two synthesized (3,3)-connected triazine-based COFs demonstrate high specific surface area and good thermal and chemical stability. COFZ1 shows good CO2 adsorption selectivities for different CO2 and N2 volume percentage systems at 273 K and 1 bar, with an ideal adsorbed solution theory (IAST) CO2 selectivity (i...

To move toward more energy-efficient adsorption-based processes, there is a need for accurate multicomponent data under realistic conditions. While the Ideal Adsorbed Solution Theory (IAST) has been established as the preferred prediction method due to its simplicity, limitations and inaccuracies for less ideal adsorption systems have been reported. Here, we use amine-functionalized derivatives of the UiO-66 structure to change the extent of homogeneity of the internal surface toward the adsorption of the two probe molecules carbon dioxide and ethylene...

Hybrid hydrogen-bonded (H-bonded) frameworks built from charged components or metallotectons offer diversified guest-framework interactions for target-specific separations. We present here the first study to systematically explore the coordination chemistry of monovalent halide anions, i.e., F-, Cl-, Br-, and I-, for developing hybrid H-bond synthons, enabling the controllable construction of microporous H-bonded frameworks exhibiting fine-tunable surface polarity within the adaptive cavities for realistic xenon/krypton (Xe/Kr) separation...

Mixture adsorption properties of porous materials are critical to determine their potential as adsorbents in separation applications. Toward the discovery of optimal adsorbents, in silico screening studies typically employ the grand canonical Monte Carlo (GCMC) technique to compute adsorption properties of gas mixtures in materials of interest at a given condition (i.e., composition, total pressure, and temperature) or to compute their adsorption properties for each component, followed by utilizing methods to predict mixture adsorption isotherms...

An ethynyl-modified interpenetrated MOF material with lvt topology, [Cu2 (BTEB)(NMF)2 ]·NMF·8H2 O (compound 1, H4 BTEB = 4,4',4'',4'''-(benzene-1,2,4,5-tetrayltetrakis(ethyne-2,1-diyl))tetrabenzoic acid, NMF = N -Methylformamide), was successfully synthesized by using an alkynyl-functionalized H4 BTEB organic ligand under solvothermal conditions. Structural analysis shows that compound 1, consisting of a tetradentate carboxylic acid ligand and classical [Cu2 (CO2 )4 ] paddle-wheel structure building units, has a rare 4-connected lvt topology with dual interpenetrating structure, which can improve the framework stability, as well as the gas adsorption capacity and selectivity due to the restricted pore channel...

Measurements of gas mixture adsorption equilibria at high pressures are important for assessing actual adsorbent selectivities but are often out of reach, given the challenging nature of the required experiments. Here, we report a high-pressure gravimetric binary gas adsorption equilibrium measurement system based on simultaneous gas density and mixture adsorption measurements in a single gas cell coupled to a magnetic-suspension balance. Compared to traditional techniques which rely on analytical measurements of gas composition, this approach does not require any sampling...

Developing metal-organic framework (MOF) adsorbents with excellent performance and robust stability is of critical importance to reduce CO2 emissions yet challenging. Herein, a robust ultra-microporous MOF, Cu(bpfb)(bdc), with mixed ligands of N, N'-(1,4-phenylene)diisonicotinamide (bpfb), and 1,4-dicarboxybenzene (bdc) was delicately constructed. Structurally, this material possesses double-interpenetrated frameworks formed by two staggered, independent frameworks, resulting in two types of narrow ultra-micropores of 3...