Practical considerations in the design and use of porous liquids

Mahdavi, Hamid; Smith, Stefan J. D.; Mulet, Xavier; Hill, Matthew

doi:10.1039/d1mh01616d

Cited by 34 publications

(32 citation statements)

References 126 publications

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“…There are no significant changes in thermal stability, binding energies, and chemical structure of both samples using TGA, XPS, and 1 H NMR, respectively. However, a proportion of 4-tert-butylcalix [6]arene and sulfur groups was reduced relative to the terephthalic proton but remained in the same binding energy in XPS and chemical shifts in 1 H NMR. The UiO-66-Calix EX-TPB also showed greatly increased maximum adsorption capacity for N 2 and a slight decrease in surface area.…”

Section: ■ Results and Discussionmentioning

confidence: 96%

“…Porous liquids (PLs) are a new class of material possessing the fluidity and mass transfer properties of fluids combined with the permanent porosity and molecular sieving properties of the porous solid . PLs attract interest from both academia and industry in various applications such as homogeneous catalysis, novel reaction media, and gas adsorption due to their exceptional physicochemical properties. − PLs can be classified into three categories based on the composition and nature of the porous host, namely: Type I PLs, which are neat liquids consisting of a single molecule with permanent pores; Type II PLs, which contain dissolved porous host in excluded solvent from the pores; and the Type III PLs, which are porous host dispersed in a solvent where the solvent is sterically hindered from occupying the pores. − The Type II and III PLs hold the most promise among all types of PLs for industrial applications…”

Section: Introductionmentioning

confidence: 99%

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Underlying Polar and Nonpolar Modification MOF-Based Factors that Influence Permanent Porosity in Porous Liquids

Mahdavi

Eden

Doherty

et al. 2022

ACS Appl. Mater. Interfaces

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It is increasingly apparent that porous liquids (PLs) have unique use cases due to the combination of ready liquid handling and their inherently high adsorption capacity. Among the PL types, those with permanent porosity are the most promising. Although Type II and III PLs have economic synthetic methods and can be made from a huge variety of metal−organic frameworks (MOFs) and solvents, these nanocomposites still need to be stable to be useful. This work aims to systematically explore the possibilities of creating PLs using different MOF modification methods. This delivered underpinning insights into the molecular-level influence between solvent and MOF on the overall nanocomposite stability. Zirconium-based metal−organic frameworks were combined with two different solvents of varying chemistry to deliver CO 2 sorption capacities as high as 2.9 mmol g −1 at 10 bar. The results of the study could have far-reaching ramifications for future investigations in the PL field.

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Section: ■ Results and Discussionmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

Underlying Polar and Nonpolar Modification MOF-Based Factors that Influence Permanent Porosity in Porous Liquids

Mahdavi

Eden

Doherty

et al. 2022

ACS Appl. Mater. Interfaces

Self Cite

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show abstract

“…Such porous liquids could be a potential platform for storing industrial exhaust CO 2 and releasing it to provide a large regional concentration of CO 2 near the catalytic site for the cyclic carbonates production. Nonetheless, only a few porous liquid instances, such as SiO 2 , zeolites, organic cages, metal organic polyhedras (MOPs), and porous MOFs and COFs, have been studied so far. − …”

Section: Thermocatalytic Co2 Conversion To Cyclic Carbonatesmentioning

confidence: 99%

Thermo-, Electro-, and Photocatalytic CO₂ Conversion to Value-Added Products over Porous Metal/Covalent Organic Frameworks

et al. 2022

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Metrics & MoreArticle Recommendations * sı Supporting Information CONSPECTUS:The continuing increase of the concentration of atmospheric CO 2 has caused many environmental issues including climate change. Catalytic conversion of CO 2 using thermochemical, electrochemical, and photochemical methods is a potential technique to decrease the CO 2 concentration and simultaneously obtain value-added chemicals. Due to the high energy barrier of CO 2 however, this method is still far from large-scale applications which requires high activity, selectivity, and stability. Therefore, development of efficient catalysts to convert CO 2 to different products is urgent. With their well-engineered pores and chemical compositions, high surface area, elevated CO 2 adsorption capability, and adjustable active sites, porous crystalline frameworks including metal−organic frameworks (MOFs) and covalent organic frameworks (COFs) are potential materials for catalytic CO 2 conversion.Here, we summarize our recent work on MOFs and COFs for thermocatalytic, electrocatalytic, and photocatalytic CO 2 conversion and describe the structure−activity relationships that could guide the design of effective catalysts.The first section of this paper describes imidazolium-functionalized porous MOFs, including porous liquid and cationic MOFs with nucleophilic halogen ions, which can promote thermocatalytically CO 2 cycloaddition reaction with epoxides toward cyclic carbonates at one bar pressure. A porous liquid MOF takes on the role of a CO 2 reservoir to tackle the low local CO 2 concentrations in gas−liquid−solid heterogeneous reactions. Imidazolium-functionalized MOFs with halogen ions for CO 2 cycloaddition could avoid the use of cocatalysts, and this leads to milder and more facile experimental conditions and separation processes.In a section dealing with the electrocatalytic CO 2 reduction reaction (CO 2 RR), we developed a series of conductive porous framework materials with fast electron transmission capabilities, which afford high current densities and outperform the traditional MOF and COF catalysts that have been reported. The intrinsically conductive two-dimensional 2D MOFs and COFs nanosheets based on the fully π-conjugated phthalocyanine motif with excellent electron transport capability were prepared, and strong electron transporters were also integrated into metalloporphyrin-based COFs for CO 2 RR. Cu 2 O quantum dots and Cu nanoparticles (NPs) can be uniformly dispersed on porous conductive MOFs/COFs to afford synergistic and/or tandem electrocatalysts, which can achieve highly selective production of CH 4 or C 2 H 4 in CO 2 RR. A third section describes our efforts to facilitate electron−hole separation in CO 2 photocatalysis. Our focus is on regulation of coordination spheres in MOFs, fabrication of the architecture of MOF heterojunctions, and engineering MOF films to facilitate photocatalytic CO 2 reduction. Finally, we discuss several problems associated with the studies of MOFs and COFs for CO 2 conversion and consider some pros...

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“…14,15 Since their conceptualisation, there have now been reports of all four types of porous liquids. 9,14,[16][17][18] While porous solids are applicable in a wide range of applications, including molecular separations and catalysis, [19][20][21] liquids have potential differentiable advantages because they can flow and might also promote more rapid heat transfer and dissipation. 22 By contrast, the porosity per unit volume for porous liquids is thus far much lower than for porous solids.…”

Section: Introductionmentioning

confidence: 99%

Shining a Light on Photoresponsive Type III Porous Liquids

Brand

Rankin

Cooper

et al. 2022

Preprint

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Porous materials are the subject of extensive research because of potential applications in areas such as gas adsorption and molecular separations. Until recently, most porous materials were solids, but there is now an emerging class of materials known as porous liquids. The incorporation of intrinsic porosity or cavities in a liquid can result in free-flowing materials that are capable of gas uptakes that are significantly higher than conventional non-porous liquids. A handful of porous liquids have also been investigated for gas separations. Until now, the release of gas from porous liquids has relied on molecular displacement (e.g., by adding small solvent molecules), pressure or temperature swings, or sonication. Here, we explore a new method of gas release that involves photoisomerisable porous liquids comprising a photoresponsive MOF dispersed in an ionic liquid. This results in the selective uptake of CO2 over CH4, and allows gas release to be controlled by using UV light.

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Practical considerations in the design and use of porous liquids

Abstract: The possibility of creating well-controlled empty space within liquids is conceptually intriguing, and from an application perspective, full of potential. Since the concept of porous liquids (PLs) arose several years...

Cited by 34 publications

References 126 publications

Underlying Polar and Nonpolar Modification MOF-Based Factors that Influence Permanent Porosity in Porous Liquids

Underlying Polar and Nonpolar Modification MOF-Based Factors that Influence Permanent Porosity in Porous Liquids

Thermo-, Electro-, and Photocatalytic CO₂ Conversion to Value-Added Products over Porous Metal/Covalent Organic Frameworks

Shining a Light on Photoresponsive Type III Porous Liquids

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Practical considerations in the design and use of porous liquids

Abstract: The possibility of creating well-controlled empty space within liquids is conceptually intriguing, and from an application perspective, full of potential. Since the concept of porous liquids (PLs) arose several years...

Cited by 34 publications

References 126 publications

Underlying Polar and Nonpolar Modification MOF-Based Factors that Influence Permanent Porosity in Porous Liquids

Underlying Polar and Nonpolar Modification MOF-Based Factors that Influence Permanent Porosity in Porous Liquids

Thermo-, Electro-, and Photocatalytic CO2 Conversion to Value-Added Products over Porous Metal/Covalent Organic Frameworks

Shining a Light on Photoresponsive Type III Porous Liquids

Contact Info

Product

Resources

About

Thermo-, Electro-, and Photocatalytic CO₂ Conversion to Value-Added Products over Porous Metal/Covalent Organic Frameworks