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Adsorption‐based removal of carbon dioxide (CO2) from gas mixtures has demonstrated great potential for solving energy security and environmental sustainability challenges. However, due to similar physicochemical properties between CO2 and other gases as well as the co‐adsorption behavior, the selectivity of CO2 is severely limited in currently reported CO2‐selective sorbents. To address the challenge, we create a bioinspired design strategy and report a robust, microporous metal–organic framework (MOF) with unprecedented [Mn86] nanocages. Attributed to the existence of unique enzyme‐like confined pockets, strong coordination interactions and dipole‐dipole interactions are generated for CO2 molecules, resulting in only CO2 molecules fitting in the pocket while other gas molecules are prohibited. Thus, this MOF can selectively remove CO2 from various gas mixtures and show record‐high selectivities of CO2/CH4 and CO2/N2 mixtures. Highly efficient CO2/C2H2, CO2/CH4, and CO2/N2 separations are achieved, as verified by experimental breakthrough tests. This work paves a new avenue for the fabrication of adsorbents with high CO2 selectivity and provides important guidance for designing highly effective adsorbents for gas separation. [ABSTRACT FROM AUTHOR]

Regarding the global energy crisis, it is of profound significance to develop spontaneous power generators that harvest natural energy. Fabricating humidity‐responsive actuators that can conduct such energy transduction is of paramount importance. Herein, we incorporate covalent organic frameworks with flexible polyethylene glycol to fabricate rigid‐flexible coupled membrane actuators. This strategy significantly improves the mechanical properties and humidity‐responsive performance of the actuators, meanwhile, the existence of ordered structures enables us to unveil the actuation mechanism. These high‐performance actuators can achieve various actuation applications and exhibit interesting self‐oscillation behavior above a water surface. Finally, after being coupled with a piezoelectric film, the bilayer device can spontaneously output electricity over 2 days. This work paves a new avenue to fabricate rigid‐flexible coupled actuators for self‐sustained energy transduction. [ABSTRACT FROM AUTHOR]

Purifying methane (CH 4 ) from natural gas and coal mine methane (CMM) is of great significance but challenging in the chemical industry. Herein, a robust ultramicroporous metal-organic framework (MOF) is reported, which can be synthesized on a gram scale by stirring under room temperature. Single-component adsorption isotherms of gases (CH 4 , ethane (C 2 H 6 ), propane (C 3 H 8 ), nitrogen (N 2 )) and breakthrough experiments indicate that the MOF can separate CH 4 efficiently from CH 4 /C 2 H 6 /C 3 H 8 ternary mixture, with super high purity-CH 4 production of 154.7 cm 3  g -1 . Additionally, the MOF shows higher CH 4 capacity than N 2 , resulting in excellent separation performance for the CH 4 /N 2 mixture. Notably, the binding sites of gases can be precisely determined by single-crystal X-ray data, further confirmed by molecular simulation. It is found that there are multiple hydrogen bonds and C─H···π interactions between the gases and the framework. This work offers an excellent candidate material for CH 4 purification with both high capacity and separation efficiency., (© 2024 Wiley‐VCH GmbH.)

Removal of carbon dioxide (CO 2 ) from a CO 2 /N 2 mixture by utilizing CO 2 -selective sorbents is important from the perspective of energy security and environmental sustainability. Herein, a microporous metal-organic framework (MOF) composed of manganese(II) and a bifunctional linker 5-(4 H -1,2,4-triazol-4-yl)benzene-1,3-dicarboxylic acid (H 2 L), [Mn(HL) 2 ] ( 1 ) is designed and synthesized using a hydrothermal method. Characterized by single-crystal X-ray diffraction (SCXRD), a microporous channel was found in the structure of compound 1 along the a -axis. Attributed to hydrogen-binding interactions between CO 2 molecules and N- and O-donor ligands in its microporous one-dimensional (1D) channel, compound 1 exhibits favorable adsorption of CO 2 over N 2 . Further, verified by experimental breakthrough tests, the CO 2 /N 2 mixture can be separated efficiently. This work provides potential guidance for designing CO 2 -selective MOFs for CO 2 /N 2 separation.

One-step adsorptive purification of ethylene (C 2 H 4 ) from a ternary mixture of acetylene (C 2 H 2 ), C 2 H 4 , and ethane (C 2 H 6 ) by a single material is of great importance but challenging in the petrochemical industry. Herein, a chemically robust olefin-linked covalent organic framework (COF), NKCOF-62, is designed and synthesized by a melt polymerization method employing tetramethylpyrazine and terephthalaldehyde as cheap monomers. This method avoids most of the disadvantages of classical solvothermal methods, which enable the cost-effective kilogram fabrication of olefin-linked COFs in one pot. Furthermore, NKCOF-62 shows remarkably selective adsorption of C 2 H 2 and C 2 H 6 over C 2 H 4 thanks to its unique pore environments and suitable pore size. Breakthrough experiments demonstrate that polymer-grade C 2 H 4 can be directly obtained from C 2 H 2 /C 2 H 6 /C 2 H 4 (1/1/1) ternary mixtures through a single separation process. Notably, NKCOF-62 is the first demonstration of the potential to use COFs for C 2 H 2 /C 2 H 6 /C 2 H 4 separation, which provides a blueprint for the design and construction of robust COFs for industrial gas separations.

Adsorption-based removal of carbon dioxide (CO 2 ) from gas mixtures has demonstrated great potential for solving energy security and environmental sustainability challenges. However, due to similar physicochemical properties between CO 2 and other gases as well as the co-adsorption behavior, the selectivity of CO 2 is severely limited in currently reported CO 2 -selective sorbents. To address the challenge, we create a bioinspired design strategy and report a robust, microporous metal-organic framework (MOF) with unprecedented [Mn 86 ] nanocages. Attributed to the existence of unique enzyme-like confined pockets, strong coordination interactions and dipole-dipole interactions are generated for CO 2 molecules, resulting in only CO 2 molecules fitting in the pocket while other gas molecules are prohibited. Thus, this MOF can selectively remove CO 2 from various gas mixtures and show record-high selectivities of CO 2 /CH 4 and CO 2 /N 2 mixtures. Highly efficient CO 2 /C 2 H 2 , CO 2 /CH 4 , and CO 2 /N 2 separations are achieved, as verified by experimental breakthrough tests. This work paves a new avenue for the fabrication of adsorbents with high CO 2 selectivity and provides important guidance for designing highly effective adsorbents for gas separation., (© 2023 Wiley-VCH GmbH.)

Two C 2 H 6 -selective metal-organic framework (MOF) adsorbents with ultrahigh stability, high surface areas, and suitable pore size have been designed and synthesized for one-step separation of ethane/ethylene (C 2 H 6 /C 2 H 4 ) under humid conditions to produce polymer-grade pure C 2 H 4 . Experimental results reveal that these two MOFs not only adsorb a high amount of C 2 H 6 but also display good C 2 H 6 /C 2 H 4 selectivity verified by fixed bed column breakthrough experiments. Most importantly, the good water stability and hydrophobic pore environments make these two MOFs capable of efficiently separating C 2 H 6 /C 2 H 4 under humid conditions, exhibiting the benchmark performance among all reported adsorbents for separation of C 2 H 6 /C 2 H 4 under humid conditions. Moreover, the affinity sites and their static adsorption energies were successfully revealed by single crystal data and computation studies. Adsorbents described in this work can be used to address major chemical industrial challenges., (© 2022 Wiley-VCH GmbH.)