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Flexible metal–organic materials (FMOMs) with stepped isotherms can offer enhanced working capacity in storage applications such as adsorbed natural gas (ANG) storage. Unfortunately, whereas >1000 FMOMs are known, only a handful exhibit methane uptake of >150 cm3/cm3at 65 atm and 298 K, conditions relevant to ANG. Here, we report a double-walled 2-fold interpenetrated diamondoid (dia) network, X-dia-6-Ni,[Ni2L4(μ-H2O)]n, comprising a new azo linker ligand, L–(L–= (E)-3-(pyridin-4-yldiazenyl)benzoate) and 8-connected dinuclear molecular building blocks. X-dia-6-Niexhibited gas (CO2, N2, CH4) and liquid (C8 hydrocarbons)-induced reversible transformations between its activated narrow-pore βphase and γ, a large-pore phase with ca. 33% increase in unit cell volume. Single-crystal X-ray diffraction (SCXRD) studies of the as-synthesized phase α, β, and γrevealed that structural transformations were enabled by twisting of the azo moiety and/or deformation of the MBB. Further insight into these transformations was gained from variable temperature powder XRD and in situvariable pressure powder XRD. Low-temperature N2and CO2sorption revealed stepped Type F–II isotherms with saturation uptakes of 422 and 401 cm3/g, respectively. X-dia-6-Niexhibited uptake of 200 cm3/cm3(65 atm, 298 K) and a high CH4working capacity of 166 cm3/cm3(5–65 bar, 298 K, 33 cycles), the third highest value yet reported for an FMOM and the highest value for an FMOM with a Type F–II isotherm.

Soft porous crystals (SPCs) are novel porous materials that exhibit significant global crystal structure deformations under external stimuli. The crystal structure deformation brings strong switch effects and hysteresis effects, which can be used to achieve highly selective separations for similar gas molecules. Among SPCs, soft porous organic cages (POCs) are particularly interesting due to their unique advantages in stability and processability. The soft nonbonding interactions in POCs lead to more delicate structural deformations and complicated sorption isotherms. Therefore, compared to rigid porous materials, it is more difficult to understand, predict, and rationally control the gas uptakes of POCs. In this work, we advance this field by employing a hybrid Grand Canonical Monte Carlo/Molecular Dynamics strategy to investigate the unique sorption behavior of a POC, named NKPOC-1, upon exposure to CO2. The experimental multistep sorption isotherms with large hysteresis at different temperatures are well reproduced. We further elucidate the distinct sorption and crystal structure deformation mechanisms at different temperatures, demonstrating the unusual complexity of POC gas adsorption. To the best of our knowledge, this is the first thorough theoretical study of understanding the sorption mechanism of soft POCs. Also, the methodology used in this work provides a generally effective way to simulate the adsorption behaviors in highly flexible materials.

Removal of carbon dioxide (CO2) from a CO2/N2mixture by utilizing CO2-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-(4H-1,2,4-triazol-4-yl)benzene-1,3-dicarboxylic acid (H2L), [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 1along the a-axis. Attributed to hydrogen-binding interactions between CO2molecules and N- and O-donor ligands in its microporous one-dimensional (1D) channel, compound 1exhibits favorable adsorption of CO2over N2. Further, verified by experimental breakthrough tests, the CO2/N2mixture can be separated efficiently. This work provides potential guidance for designing CO2-selective MOFs for CO2/N2separation.

The synthesis of single-crystal, one-dimensional (1D) polymers is of great importance but a formidable challenge. Herein, we report the synthesis of single-crystal 1D ladder polymers in solution by dynamic covalent chemistry. The three-dimensional electron diffraction technique was used to rigorously solve the structure of the crystalline polymers, unveiling that each polymer chain is connected by double covalent bridges and all polymer chains are packed in a staggered and interlaced manner by π–π stacking and hydrogen bonding interactions, making the crystalline polymers highly robust in both thermal and chemical stability. The synthesized single-crystal polymers possess permanent micropores and can efficiently remove CO2from the C2H2/CO2mixture to obtain high-purity C2H2, validated by dynamic breakthrough experiments. This work demonstrates the first example of constructing single-crystal 1D porous ladder polymers with double covalent bridges in solution for efficient C2H2/CO2separation.

Covalent organic frameworks (COFs) are crystalline porous polymers constructed from organic building blocks into ordered two- or three-dimensional networks through dynamic covalent bonds. Attributed to their high porosity, well-defined structure, tailored functionality and excellent chemical stability, COFs have been considered ideal sorbents for various separation applications. The synthesis of COFs mainly employs the solvothermal method, which usually requires organic solvents in sealed Pyrex tubes, resulting in unscalable powdery products and environmental pollution that seriously limits their practical applications. Herein, our protocol focuses on an emerging synthesis method for COFs based on organic flux synthesis without adding solvents. The generality of this synthesis protocol has been applied in preparing various types of COFs, including olefin-linked, imide-linked, Schiff-based COFs on both gram and kilogram scales. Furthermore, organic flux synthesis avoids the disadvantages of solvothermal synthesis and enhances the crystallization and porosity of COFs. Typically, COF synthesis takes 3–5 d to complete, and subsequent washing procedures leading to pure COFs need 1 d. The procedure for kilogram-scale production of COFs with commercially available monomers is also provided. The resulting COFs are suitable for separation applications, particularly as adsorbent materials for industrial gas separation and water treatment applications. The protocol is suited for users with prior expertise in the synthesis of inorganic materials and porous organic materials.

In this paper, we examine the problem of indexing over non-metric distance functions. In particular, we focus on a general class of distance functions, namely Bregman Divergence[6], to support nearest neighbor and range queries. Distance functions such as KL-divergence and Itakura-Saito distance, are special cases of Bregman divergence, with wide applications in statistics, speech recognition and time series analysis among others. Unlike in metric spaces, key properties such as triangle inequality and distance symmetry do not hold for such distance functions. A direct adaptation of existing indexing infrastructure developed for metric spaces is thus not possible. We devise a novel solution to handle this class of distance measures by expanding and mapping points in the original space to a new extendedspace. Subsequently, we show how state-of-the-art tree-based indexing methods, for low to moderate dimensional datasets, and vector approximation file (VA-file) methods, for high dimensional datasets, can be adapted on this extended spaceto answer such queries efficiently. Improved distance bounding techniques and distribution-based index optimization are also introduced to improve the performance of query answering and index construction respectively, which can be applied on both the R-trees and VA files. Extensive experiments are conducted to validate our approach on a variety of datasets and a range of Bregman divergence functions.

Moving object indexing and query processing is a well studied research topic, with applications in areas such as intelligent transport systems and location-based services. While much existing work explicitly or implicitly assumes a deterministic object movement model, real-world objects often move in more complex and stochastic ways. This paper investigates the possibility of a marriage between moving-object indexing and probabilistic object modeling. Given the distributions of the current locations and velocities of moving objects, we devise an efficient inference method for the prediction of future locations. We demonstrate that such prediction can be seamlessly integrated into existing index structures designed for moving objects, thus improving the meaningfulness of range and nearest neighbor query results in highly dynamic and uncertain environments. The paper reports on extensive experiments on the Bx-tree that offer insights into the properties of the paper's proposal.

Recent studies have pointed out that the widespread iron deposits in southwestern Fujian metallogenic belt (SFMB) (China) are skarn-type deposits associated with the Yanshanian granites. There is still excellent potential for mineral exploration because large areas in this belt are covered by forest. A new predictive model for mapping skarn-type Fe deposit prospectivity in this belt was developed and focused on in this study, using five criteria as evidence: (1) the contact zones of Yanshanian granites (GRANITE); (2) the contact zones within the late Paleozoic marine sedimentary rocks and the carbonate formations (FORMATION); (3) the NE-NNE-trending faults (FAULT); (4) the zones of skarn alterations (SKARN); and (5) the aeromagnetic anomaly (AEROMAGNETIC). The fuzzy weights of evidence (FWofE) method, developed from the classical weights of evidence (WofE) and based on fuzzy sets and fuzzy probabilities, could provide smaller variances and more accurate posterior probabilities and could effectively minimize the uncertainty caused by omitted or wrongly assigned data and be more flexible than the WofE. It is an efficient and widely used method for mineral potential mapping. Random forests (RF) is a new and useful method for data-driven predictive mapping of mineral prospectivity method, and needs further scrutiny. Both prospectivity results respectively using the FWofE and RF methods reveal that the prediction model for the skarn-type Fe deposits in the SFMB is successful and efficient. Both methods suggested that the GRANITE and FORMATION are the most valuable evidence maps, followed by SKARN, AEROMAGNETIC, and FAULT. This is coincident with the skarn-type Fe deposit mineral model in the SFMB. The unstable performance experienced when FORMATION was omitted might indicate that the highest uncertainty and risk in follow-up exploration is related to the sequences. In addition, the performance of the RF method for the skarn-type Fe deposits prospectivity in the SFMB is better than the FWofE; therefore, it could be used to guide further exploration of skarn-type Fe prospects in the SFMB.

This paper is concerned with the observer-based fuzzy adaptive fault-tolerant control problem for nonlinear steering control (NSC) system of unmanned surface vehicle (USV) with unmeasurable states, sideslip angle, and steering machine fault. To facilitate the controller design, the Takagi-Sugeno (T-S) model is used to deal with the fuzzy control problem of NSC system, and the modeling error analysis (MEA) is conducted for the T-S model using the real course tracking data. By introducing a pre-filter, the large heading change rate can be avoided and the robustness of controller is improved. Then, a fuzzy adaptive observer (FAO) is developed, based on which an adaptive mechanism is given to estimate the unmeasurable states, sideslip angle, and fault signals simultaneously. Furthermore, utilizing the online estimation information provided by FAO, a FAO-based adaptive fault-tolerant controller is designed to mitigate the effects of sideslip angle and fault. Finally, simulation examples and comparison experiment for “Qingshan” USV demonstrate the apparent performance of the developed method.

Fabricating insoluble and infusible porous materials into gels for advanced applications is of great importance but has formidable challenges. Here, we present a general, facile, and scalable protocol to fabricate covalent organic framework (COF) gels using a group-protection synthesis strategy. To prove the generality of this strategy, we successfully prepared 10 types of COF organohydrogels with high crystallinity, porosity, good mechanical properties, and excellent solvent and freezing resistance. Notably, these COF organohydrogels can easily transform into hydrogels, organogels, and aerogels, breaking the gaps between different types of COF gels. An in-depth mechanism investigation unveils that the group-protection strategy effectively slows down the formation rate and regulates the morphology of COFs, benefiting the formation of cross-linked nanofibers/nanosheets to produce COF gels. We also find that the hydrogen bond network formed by the organic/water binary solvent and functional groups in the COF skeletons plays a vital role in creating organohydrogels and maintaining frost resistance and solvent resistance. As an application demonstration, COF gels installed with photoresponsive azobenzene groups show excellent solar energy absorption, photothermal conversion, and water transmission performances, demonstrating great potential in solar desalination. This work enriches the synthesis toolboxes for COF gels and expands the application scope of COFs.

This article investigates the problem of fault estimation and ${H}_{\infty }$ fuzzy active fault-tolerant control design for ship steering autopilot (SSA) system with simultaneous partial states that are not easily measured, actuator (steering machine), and sensor (compass) faults. First, the Takagi–Sugeno (T–S) fuzzy model is employed to describe the nonlinear dynamics of SSA system, and the feasibility of the designed model is analyzed with the collected navigation data. Then, an auxiliary ${H}_{\infty }$ fuzzy observer (AHFO) is introduced for asymptotic estimation of unknown states and faults. Using the observation information provided by the AHFO, an AHFO-based active fault-tolerant controller (AHFO-based AFTC) is designed for stabilizing the SSA system with steering and compass faults to achieve satisfactory control requirements, including stability and tracking performance. Finally, an example of ship course fault-tolerant control is conducted to verify the effectiveness of this method.

Covalent organic frameworks (COFs) are a class of crystalline porous materials with ordered nanochannels, designable functionality, and excellent chemical/thermal stability. Taking advantage of these exceptional properties, COFs have emerged as ideal platforms for designing proton conductors. Since the first successful realization of COFs as proton conductors in 2014, considerable efforts have been devoted to this field. This Review summarizes the evolution of COFs as proton conductors from powder-pressed pellets to self-standing membranes, as well as the properties of these proton-conducting COFs. Finally, current challenges and prospects for COFs in the field of proton conductors are discussed.

Abstract: The bending and buckling of the microcomponents show size dependency. The strain gradient elasticity theory is proposed to explain the size dependency. In this paper, we derive the theoretical relations among the modified strain gradient elasticity theory, the modified couple stress theory and the general strain gradient elasticity theory, and clarify the degradation relation. The general theory includes all strain gradients while the modified strain gradient elasticity theory and the modified couple stress theory only contain part of strain gradients. By ignoring the deviatoric part of the strain gradients \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\eta _{ijk}^{'(2)}$$\end{document}or the symmetric part of the strain gradients \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\eta _{ijk}^{s}$$\end{document}, the general theory is simplified as the modified couple stress theory or the modified strain gradient elasticity theory, respectively. The ability of the general theory and the reduced theories in describing the bending and buckling response of the partially covered laminated microplate is subsequently compared. Results reveal that the general theory predicts smaller bending deflection and axial displacement while larger buckling load than that of the reduced theories. The general theory is more effective in reflecting the size effects. In addition, it is found that the increase of the thickness or radius of the upper elastic layer makes the buckling load increase while the deflection increase firstly and then decrease. There exists the specific radius ratio and thickness ratio to make the clamped-clamped microplate achieve the maximum deflection. Graphical abstract:

Phase transition, energy storage, and other activities depend critically on the size variations of nanomaterials for their heat capacity. The size variation of the nanomaterial is also equally important to the thermodynamic properties for chemical reaction processes. Based on this, it will be fascinating to examine how the surface heat capacity of nanomaterials changes with size. Herein, we used an in situ microcalorimeter to report a general approach to obtaining the regular patterns of numerical changes in the surface heat capacity at different sizes and temperatures when the chemical reactions of cuprous oxide (Cu2O) take place in the liquid phase. We synthesized four Cu2O nanocubes with uniform size distributions, which range from 40 to 120 nm, by using the liquid-phase reduction method. Combined with the principle of thermodynamic cycle and transition state theory, the effects of size and temperature changes on the standard molar formation thermodynamic properties, surface thermodynamic properties, and specific surface thermodynamic properties of Cu2O nanocubes were calculated and analyzed. The calculated results are in agreement with the established thermodynamic model. It is inspiring that we find that Cu2O nanocubes also have a critical size in the range of 55–67 nm, and their molar surface heat capacity and specific surface heat capacity are 59.35 and 59.31 nm, respectively. This property allows them to exhibit differences in thermal resistance from bulk materials within an acceptable range of error. This work has important scientific significance and values for enriching and developing the surface physical chemistry and understanding the energy storage and other processes of nanomaterials.

Enzymes are natural catalysts with high catalytic activity, substrate specificity and selectivity. Their widespread utilization in industrial applications is limited by their sensitivity to harsh reaction conditions and difficulties relating to their removal and re-use after the reaction is complete. These limitations can be addressed by immobilizing the enzymes in solid porous supports. Covalent organic frameworks (COFs) are ideal candidate carriers because of their good biocompatibility, long-term water stability and large surface area. In post-synthetic immobilization, the enzyme is added to an existing COF; this has had limited success because of enzyme leaching and pore blockage by enzymes that are too large. Direct-immobilization methods—building the COF around the enzyme—allow tailored incorporation of proteins of any size and result in materials with lower levels of leaching and better mass transport of reactants and products. This protocol describes direct-immobilization methods that can be used to fabricate enzyme@COF (@ = engulfing) biocomposites with rationally programmed structures and functions. If COF construction requires harsh reaction conditions, the enzyme can be protected by using a removable metal-organic framework. Alternatively, a direct in situ approach, in which the enzyme and the COF monomers assemble under very mild conditions, can be used. Examples of both approaches are described: enzyme@COF-42-B/43-B capsules (enzymes including catalase, glucose oxidase, etc.) with ZIF-90 or ZPF-2 as protectors, and lipase@NKCOF-98/99 via in situ direct-immobilization methods (synthesis timing: 30–100 min). Example assays for physical and functional characterization of the COF and enzyme@COF materials are also described.

Query-aware synthetic data generation is an essential and highly challenging task, important for database management system (DBMS) testing, database application testing and application-driven benchmarking. Prior studies on query-aware data generation suffer common problems of limited parallelization, poor scalability, and excessive memory consumption, making these systems unsatisfactory to terabyte scale data generation. In order to fill the gap between the existing data generation techniques and the emerging demands of enormous query-aware test databases, we design and implement a new data generator, called Touchstone. Touchstone adopts the random sampling algorithm instantiating query parameters and the new data generation schema generating the test database, to achieve fully parallel data generation, linear scalability and austere memory consumption. It has full support of outer joins as well as non-equi-joins for application-oriented data generation. Our experimental results show that Touchstone consistently outperforms the state-of-the-art solution on TPC-H workload by a 1000× speedup without sacrificing simulation fidelity.

Developing a 100% atom economic direct amination reaction of bulky cycloolefins with NH3is important but challenging for CN bond formation. This work describes a novel strategy of employing H-mZSM-5 zeolites with meso–microporous architecture as a solid acid catalyst for highly selective preparation of cyclohexylamine by vapor-phase acid-catalyzed amination of cyclohexene with NH3. The mesoporous H-mZSM-5 compared to the referenced microporous H-ZSM-5 delivers outstanding catalytic activity, providing a cyclohexylamine selectivity of 95.6% and 4.9% conversion at 9 MPa and 300 °C. The relationship of zeolite structure and catalytic activity is established by using multiple techniques, such as N2adsorption–desorption, XRD, SEM, TEM, Py-FTIR and NH3-TPD. The pore structure and Brønsted-acid sites of the zeolites played crucial roles in the cyclohexene amination reaction. Based on in situFT-IR spectroscopy and DFT simulations, the reactant adsorption and product desorption, and molecular diffusion on the mesoporous HZSM-5 suggested that the accessible Brønsted-acid sites in the 10-MR micropores are the key factors controlling the catalytic process.

In order to move towards sustainable development, the discovery of energy-efficient and environmentally friendly materials has become increasingly imperative. Covalent organic frameworks (COFs) as emerging designable crystalline porous materials have captured increasing attention for a wide array of clean-energy and environmental applications, attributed to their attractive advantages of low density, high surface area, adjustable and periodic pores, and functional skeletons. This review attempts to highlight the key advancements made in the green synthesis of COFs, processing of COFs, energy and environment-related applications, including gas storage, water treatment, the separation of gas mixture and organic molecules, catalysis, supercapacitors, fuel cell, and rechargeable batteries. Finally, a perspective regarding the remaining challenges and future directions on the synthesis and promising application for green chemical engineering of COFs has also been presented based on current achievements.

Is an inferior model completely useless in complex systems modeling? This study proposes a novel multi-model output fusion approach that makes the best of the outputs from multi-models, i.e., using the limited superior results from inferior models to compensate for certain inferior results from even superior models. For fusing the outputs from multi-models, the weight assigned to each output is calculated based on two factors, namely the accuracy of each model and the similarity between the testing input and the focus data used for constructing the respective model. Specifically for similarity calculation, the focus data list is identified based on set operations. There are three theoretical contributions of this study, namely accuracy-and-similarity-based weight calculation, the set-operation-based similarity calculation which is an addition to traditional distance-based calculation, and the high compatibility of the proposed approach which is independent from any baseline approach. A practical case of overall reconnaissance capability evaluation of the Unmanned Aerial Vehicle (UAV) swarm is studied for validation. Primary results indicate that the proposed approach can outperform two single models: the backpropagation neural network (BPNN) and the Radial Basis Function (RBF) neural network. Further validations demonstrate that the proposed approach also outperforms multi-model output fusion with equal weights, without model accuracy, with varied focus data percentages ranging from 0.1 to 0.9. More importantly, the proposed approach remains effective in four different conditions of multi-model outputs fusion with improvements from 9.58 % to 38.03 %. • A novel multi-model output fusion approach is proposed that fuses results of multi-models and proposes a unified output. • Superior results from inferior models are used for compensating inferior results of superior models. • New accuracy-and-similarity-based weight calculation and the set-operation-based similarity calculations are proposed. • The proposed approach is highly compatible as it is independent from any baseline approach. • Further comparisons are conducted with equal weights, without model accuracy, with varied focus data percentages. [ABSTRACT FROM AUTHOR]

Na3V2(PO4)3is a promising cathode for Na-ion batteries (NIBs) owing to the high electrochemical reversibility. The Na3V2(PO4)3has two typical polymorphs including rhombohedral and monoclinic phases; the former has been extensively studied, whereas the latter is rarely reported. Here, we successfully designed monoclinic Na3V2(PO4)-based cathode via Ga and Fe substitutions owing to the lowered lattice energy. In addition, we revealed that Ga substitution improves average voltage owing to the activation of the V4+/V5+redox couple and the Fe substitution enhances rate capability due to the decreased band gap and Na-ion diffusion activation energy. As a result, the designed monoclinic Na3V1.6Ga0.2Fe0.2(PO4)3cathode exhibits high voltage plateaus (3.4 V and 4 V) and high-rate capability (from 116.8 mA h/g at 0.2 C to 103 mA h/g at 20 C) as well as superior cycling stability (99.9% capacity retention over 4,500 cycles at 5 C). Moreover, the assembled Na3V1.6Ga0.2Fe0.2(PO4)3//hard carbon full cell delivers a high-energy density of 313.8 Wh/kg with 86.4% capacity retention after 100 cycles at 1 C. This work demonstrates the design of monoclinic Na3V2(PO4)3-based cathode via bimetallic substitution, providing a new route for development of high-energy and long-lifespan NIBs.

The practical applications of crystalline porous materials toward industrial separations require shaping them into robust monoliths (e.g., foams). The current methods are often complicated, environmentally unfriendly, and unscalable, significantly hampering their practical application. Herein, we report a scalable, facile “one-step thermomolding” method to fabricate a class of hierarchically olefin-linked covalent organic framework (COF) foams viamelt polymerization. The obtained pure COF foams possess higher crystallinity and porosity than literature, good moldability, and processability, greatly benefiting their practical applications (e.g., efficient oil-water separation with 99% removal efficiency and >100 cycle reusability). Moreover, a COF exhibiting the smallest (0.58 nm) eclipsed stacking pore among all 2-dimensional COFs with neutral skeletons is first fabricated viathis protocol, demonstrating good C2H2purification performance and recyclability, surpassing the current benchmark materials. We believe that this facile fabrication strategy can promote access to a broad diversity of new COF foams and enlighten further avenues for green routes to large-scale synthesis and usage of COFs.

Exploring new materials to manufacture proton-conducting membranes(PEMs) for fuel cells is highly significant. In this work, we fabricated two robust and highly crystalline porous covalent organic frameworks(COFs) viaa stepwise synthesis strategy. The synthesized COF structures are integrated into high-density azo and amino groups, which allow to anchor acids for accelerating proton conduction. Moreover, the COFs exhibit good chemical stability and high hydrophilicity. These features make them potential platforms for proton conduction applications. Upon loaded with H3PO4, the COFs(H3PO4@COFs) deliver a high proton conductivity of 3.15×10−2S/cm at 353 K under 95% relative humidity(RH). Furthermore, membrane electrode assemblies are fabricated using H3PO4@COF-26as the solid electrolyte for a single fuel cell outputting a maximum power density of 18 mW/cm2.

Developing cost-/energy-efficient separation techniques for purifying ethylene from an ethylene/ethane mixture is highly important but very challenging in the industrial process. Herein, using a bottom-up [8 + 2] construction approach, we rationally designed and synthesized three three-dimensional covalent organic frameworks (COFs) with 8-connected bcunetworks, which can selectively remove ethane from an ethylene/ethane mixture with high efficiency. These COF materials, which are fabricated by the condensation reaction of a customer-designed octatopic aldehyde monomer with linear diamino linkers, possess high crystallinity, good structural robustness, and high porosity. Attributed to the well-organized micro-sized pores with a nonpolar/inert pore environment, these COFs display high ethane adsorption capacity and good selectivity over ethylene, making them among the best ethane-selective adsorbents for ethylene purification. Their excellent ethylene/ethane separation performance is validated by dynamic breakthrough experiments with high-purity ethylene (>99.99%) produced through a single adsorption process. The separation performance surpasses all reported C2H6-selective COFs and even some benchmark metal–organic frameworks. This work provides important guidance for the design of new adsorbents for value-added gas purification.