Porous framework materials for energy&environment relevant applications:A systematic review

Carbon peaking and carbon neutralization trigger a technical revolution in energy&environment related fields.Development of new technologies for green energy production and storage,industrial energy saving and efficiency reinforcement,carbon capture,and pollutant gas treatment is in highly imperious demand.The emerging porous framework materials such as metal–organic frameworks(MOFs),covalent organic frameworks(COFs)and hydrogen-bonded organic frameworks(HOFs),owing to the permanent porosity,tremendous specific surface area,designable structure and customizable functionality,have shown great potential in major energy-consuming industrial processes,including sustainable energy gas catalytic conversion,energy-efficient industrial gas separation and storage.Herein,this manuscript presents a systematic review of porous framework materials for global and comprehensive energy&environment related applications,from a macroscopic and application perspective.

A Charge Equalizer in Accordion-MXene-Modified Layer Leading to Spherical Lithium Deposition

Lithium-ion batteries with polymer electrolytes(PEs)are promising candidates for high safety performance batteries.However,conventional PEs suffer from poor compatibility and high impedance of electrolyte-electrode interfaces.Herein,we present a method of the interfacial modification for PEs to inhibit lithium dendrites based on the solution to the interfacial compatibility.Our strategy is to improve the interfacial properties and inhibit the dendrite generation by coating a modified layer on PEs of the anode side with acetylene black(AB)and MXene.The mixed conductive layer(MCL)can promote the generation of Li3N and LiF with a uniform arrangement of electrons to form a dense solid electrolyte interphase layer and the even lithium-ion deposition for improving the performance and stability of the battery during cycling.After adding the MCL,the discharge capacity of solid lithium-ion batteries(SLIBs)with lithium bis(trifluoromethanesulfonyl)imide(LiTFSI)/organic modified montmorillonite(OMMT)/soybean isolate protein(SPI)/poly(vinylidene fluoride)(PVDF)(LOSP)PE from 74.2 mAh g^(-1)up to 111.1 mAh g^(-1)(AB-LiTFSI/OMMT/SPI/PVDF(AB-LOSP))and 111.6 mAh g^(-1)(AB/MXene-LiTFSI/OMMT/SPI/PVDF(AB/MXene-LOSP)).The polarization voltage dropped by 0.06 and 0.12 V,respectively.This work represents a milestone in the dendrite-free SLIBs with good performances.

Measurements and thermodynamic modeling of liquid–liquid equilibria in ternary system 2-methoxy-2-methylpropane+p-cresol+water

Liquid–liquid equilibrium(LLE)data for the ternary system 2-methoxy-2-methylpropane(methyl tert-butyl ether)+ p-cresol + water was measured at atmospheric pressure and temperatures of 298.15 K and 313.15 K.From the distribution coefficients and selectivity,it was found that 2-methoxy-2-methylpropane is an efficient solvent to extract p-cresol from wastewater.The consistency of the experimental tie-line data was verified with the Hand and Bachman equations.These data were also correlated with the non-random two liquid(NRTL)and universal quasi-chemical correlation activity coefficient(UNIQUAC)models to yield binary interaction parameters for p-cresol extraction process evaluation.Both models agreed with experiments very well,yet the NRTL model showed even smaller average deviation than the UNIQUAC model.

Measurement and correlation of phase equilibrium data of the mixtures consisting of water, resorcinol, mesityl oxide at different temperatures

Liquid–liquid equilibrium(LLE) data were measured for the ternary system of water + resorcinol + mesityl oxide under atmospheric pressure at temperatures of(298.2, 323.2, 333.2, 343.2 and 353.2) K. The reliability of the experimental data was verified by the Hand and Bachman equations. The distribution coefficient and selectivity were calculated from the experimental LLE data, which showed high efficiency of mesityl oxide extracting resorcinol from the aqueous solution. The NRTL and UNIQUAC models were employed to fit the measured experimental LLE data and yield corresponding binary interaction parameters.

Nitrogen rejection from low quality natural gas by pressure swing adsorption experiments and simulation using dynamic adsorption isotherms

In order to remove N_(2) from low quality natural gas,a mathematical model has been established by Aspen adsorption,using the CH_(4)-selective sorbent silicalite-1 pellets.The dynamic adsorption isotherm was first simulated by breakthrough simulation of a CH_(4)/N_(2) mixture at different adsorption pressures and feed flow rates based on breakthrough experiments.The resulting simulated CH_(4) dynamic adsorption amounts were very close to the experimental data at three different adsorption pressures(100,200,and 300 kPa).Moreover,a single-bed,three-step pressure swing adsorption(PSA)experiment was performed,and the results were in good agreement with the simulated data,further corroborating the accuracy of the gas dynamic adsorption isotherm obtained by the simulation method.Finally,based on the simulated dynamic adsorption isotherm of CH_(4) and N_(2),a four-bed,eight-step PSA process has been designed,which enriched 75%(vol)CH_(4) and 80%(vol)CH_(4) to 95%(vol)and 99%(vol),and provided 99%(vol)recovery.

PHOTODYNAMIC THERAPY—AN UPDATE ON CLINICAL APPLICATIONS

Photodynamic therapy(PDT)has received increased attention since the regulatory approvals of several photosensitizers and light applicators in numerous countries and regions around the world.In recent years,much progress has been seen in basic research as well as clinical application.PDT clinical application has now extended from treating malignant diseases to nonmalignant diseases.This review article will present recent clinical data published in English journals.The data will be organized according to their clinical specialties.The new development and future direction in clinical applications of PDT for the management of both malignant and nonmalignant diseases will be discussed.

Salt effect on the liquid–liquid equilibrium of the ternary (water + phenol + methyl isobutyl ketone) system: Experimental data and correlation

The effects of NaCl, KCl and Na_2SO_4 on the liquid–liquid equilibrium(LLE) data for the ternary system, water+ phenol + methyl isobutyl ketone, were determined at 0.101 MPa and 333.15 K and 343.15 K.The nonrandom two-liquid(NRTL) model was used to correlate the experimental data and to yield corresponding binary interaction parameters for these salt containing systems.The Hand and Othmer–Tobias equations were used to confirm the dependability of the determined LLE data in this work.Distribution coefficient and selectivity were used to evaluate the extraction performance of methyl isobutyl ketone with the existence of salt.The magnitude of salt effect on the water + phenol + methyl isobutyl ketone(MIBK) system is in the following order: Na_2SO_4>NaCl>KCl.

Notes in accordions-organized MXene equipped with CeO_(2) for synergistically adsorbing and catalyzing polysulfides for high-performance lithium-sulfur batteries

Limited by the shuttle effect, the application of lithium-sulfur batteries is not impressive. As an organ layered two-dimensional(2D) material, MXene has a great electrical conductivity and high specific surface area. Meanwhile, the introduction of metal oxides can restrain the shuttle effect. Hence, this paper prepared CeO_(2)/MXene as a cathode material of Li-S batteries. Ce and Ti can chemically adsorb S, and the interlayer structure of MXene can limit S while the interlayer space can alleviate volume expansion.The discharge capacity at 0.5 C is as high as 1051.1 m Ah g^(-1), and 921.9 m Ah g^(-1) after 200 cycles. The average coulombic efficiency is 97.75%. The organized MXene with CeO_(2) like notes in accordions are new efficient materials for lithium-sulfur batteries.

Ultrafine tuning of the pore size in zeolite A for efficient propyne removal from propylene

The removal of trace propyne(C_(3)H_(4))from propyne/propylene(C_(3)H_(4)/C_(3)H_(6))mixtures is a technical and challenging task during the production of polymer-grade propylene in view of their very similar size and physical properties.While some progress has been made,it is still very challenging to use some highly stable and commercially available porous materials via an energy-efficient adsorptive separation process.Herein,we report the ultrafine tuning of the pore apertures in type-A zeolites for the highly efficient removal of trace amounts of C_(3)H_(4)from C_(3)H_(4)/C_(3)H_(6)mixtures.The resulting ion-exchanged zeolite 5 A exhibits a large C_(3)H_(4)adsorption capacity(2.3 mmol g^(-1)under 10^(-4)MPa)and high C_(3)H_(4)/C_(3)H_(6)selectivity at room temperature,which were mainly attributed to the ultrafine-tuned pore size that selectively blocks C_(3)H_(6)molecules,while maintaining the stro ng adsorption of C_(3)H_(4)at low pressure region.High purity of C_(3)H_(6)(>99.9999%)can be directly obtained on this material under ambient conditions,as demonstrated by the experimental breakthrough curves obtained for both 1/99 and 0.1/99.9(V V)C_(3)H_(4)/C_(3)H_(6) mixtures.

Selective adsorption of propene over propane on Li-decorated poly(triazine imide)

Solid adsorbents that simultaneously have high selectivity and uptake capacity are highly promising as alternatives to conventional cryogenic distillation of propene/propane(C_(3)H_(6)/C_(3)H_(8)) separation.Coordinatively unsaturated metal sites(CUS) plays a vital role in selective adsorption of olefins over paraffins.Ultrathin poly(triazine imide)(PTI) nanosheets can reach rapid gas adsorption equilibrium,due to its large surface-tovolume ratio.In this work,combining the advantages of the CUS and the PTI nanosheets,Li CUSs were introduced into the PTI nanosheets for C_(3)H_(6)/C_(3)H_(8) separation.Density functional theory(DFT) calculations demonstrated the thermodynamic feasibility of incorporating Li CUSs into the PTI nanosheets.These highly exposed Li CUSs were predicted to have a higher adsorption affinity toward C_(3)H_(6) than C_(3)H_(8).Using the DFTderived force field parameters,we further performed grand canonical Monte Carlo(GCMC) simulations to investigate C_(3)H_(6)/C_(3)H_(8) adsorption on the Li–PTI complexes slit pore model with different pore widths(H).We found that the Li–PTI complexes display considerable C_(3)H_(6)/C_(3)H_(8) selectivity(4.2–7.9) under relevant conditions.Moreover,the Li–PTI complexes slit pore have large C_(3)H_(6) working capacities(1.5–4.0 mmol g-1),superior to those calculated for the most of adsorbent materials that have been reported.The Li–PTI complexes with slit pore architecture show potential as C_(3)H_(6)/C_(3)H_(8) separation materials.

Methyl functionalization of trimesic acid in copper-based metal-organic framework for ammonia colorimetric sensing at high relative humidity

Exhaled ammonia(NH_(3))can be used as a crucial biomarker of kidney and liver diseases.However,the high humidity in the detection conditions remains a challenge for accurate detection by gas sensors.Herein,a copper-based metal-organic framework(CH_(3)-Cu-BTC)with methyl(CH_(3)^(-))functionalization of trimesic acid was synthesized for NH_(3) colorimetric sensing.The CH_(3)-Cu-BTC exhibited a strong response for 5 ppm NH_(3) with high selectivity under high relative humidity(75%RH).Density functional theory(DFT)simulations indicated that the NH_(3) molecules interacted more strongly with CH_(3)-Cu-BTC than H_(2)O molecules did,and the corresponding color switching was attributed to the lone-pair electron in NH_(3) changing the coordination environment of Cu^(2+)ions,leading to an obviously visible color switching response from ruby green to blue.Based on the tailor-made pore chemistry,the precise detection of trace amounts of NH_(3) in exhaled air was realized through functionalized MOF materials.The strategy used in this study not only offers a new pathway for the rapid detection of low concentration NH_(3) under humid conditions,but also shows a method for early respiration diagnosis of kidney and liver diseases.

Reversed ethane/ethylene adsorption in a metal–organic framework via introduction of oxygen

Separation of ethane from ethylene is a very important but challenging process in the petrochemical industry.Finding an alternative method would reduce the energy needed to make 170 million tons of ethylene manufactured worldwide each year.Adsorptive separation using C2H6-selective porous materials to directly produce high-purity C2H4 is more energy-efficient.We herein report the"reversed C2H6/C2H4 adsorption"in a metal–organic framework Cr-BTC via the introduction of oxygen on its open metal sites.The oxidized Cr-BTC(O2)can bind C2H6 over C2H4 through the active Cr-superoxo sites,which was elucidated by the gas sorption isotherms and density functional theory calculations.This material thus exhibits a good performance for the separation of 50/50 C2H6/C2H4 mixtures to produce 99.99%pure C2H4 in a single separation operation.

Separation of CO_2/CH_4 and CH_4/N_2 mixtures using MOF-5 and Cu_3(BTC)_2

In this paper we used MOF-5 and Cu3（BTC）2 to separate CO2/CH4 and CI-I4/N2 mixtures under dynamic conditions. Both materials were synthesized and pelletized, thus allowing for a meaningful characterization in view of process scale-up. The materials were characterized by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. By performing breakthrough experiments, we found that Cu3（BTC）2 separated CO2/CH4 slightly better than MOF-5. Because the crystal structure of Cu3 （BTC）2 includes unsaturated accessible metal sites formed via dehydration, it predominantly interacted with CO2 molecules and more easily captured them. Conversely, MOF-5 with a suitable pore size separated CH4/N2 more efficiently in our breakthrough test.

CO_2/CH_4 and CH_4/N_2 separation on isomeric metal organic frameworks

Two isomeric metal-organic frameworks(MOFs) with 2-dimensional(2D) and 3-dimensional(3D) topologies both comprised of Cu(Ⅱ) and OTf(OTf = trifluoromethanesulfonate) ions were synthesized and characterized.The CO_2,CH_4 and N_2 adsorption properties of the two isomeric MOFs were investigated from 263 K to 298 K at0.1 MPa.The results showed that the 2D MOF exhibited a higher selectivity for CO_2 from CO_2/CH_4 and CH_4from CH_4/N_2 compared to the 3D MOF,even though it possessed a lower surface area and pore volume.The higher adsorption heats of gases on the 2D MOF inferred the strong adsorption potential energy in the layered MOFs.Dynamic separation experiments using CO_2/CH_4 and CH_4/N_2 mixtures on the two MOFs proved that the2 D MOF had a longer elution time than the 3D MOF as well as better separation abilities.

Recent advances in the synthesis of nanoscale hierarchically porous metal–organic frameworks

Nanoscale hierarchically porous metal–organic frameworks(NHP-MOFs)have received unprecedented attention in many fields owing to their integration of the strengths of nanoscale size(<1μm)and hierarchical porous structure(micro-,meso-and/or macro-pores)of MOFs.This review focuses on recent advances in the main synthetic strategies for NHP-MOFs based on different metal ions(e.g.,Cu,Fe,Co,Zn,Al,Zr,and Cr),including the template method,composite technology,post-synthetic modification,in situ growth and the grind method.In addition,the mechanisms of synthesis,regulation techniques and the advantages and disadvantages of various methods are discussed.Finally,the challenges and prospects of the commercialisation of promising NHP-MOFs are also presented.The purpose of this review is to provide a road map for future design and development of NHP-MOFs for practical application.

Shaping of metal-organic frameworks through a calcium alginate method towards ethylene/ethane separation

The separation of ethylene and ethane is a crucial,challenging and cost-intensive process in chemical engineering.Metal-organic frameworks(MOFs)are a class of novel porous adsorbents used for the separation of ethylene/ethane mixtures.However,MOFs are normally crystalline powders that cause multiple problems,such as dust,abrasion and heat/mass loss,as well as significant pressure drops on the adsorption bed resulting in a sudden stop in production.To solve these issues,we have prepared four different sphere-shaped adsorbents,including Mg-gallate,Co-gallate,MUV-10(Mn)and MIL-53(Al)using a calcium alginate method to achieve excellent ethylene/ethane separation performance.The performance of the sphere-shaped adsorbents has been validated using mechanical strength measurements,powder X-ray diffraction,scanning electron microscopy,thermogravimetric analysis,gas adsorption isotherms and dynamic breakthrough experiments.The excellent mechanical strength of these sphere-shaped adsorbents meets the criteria for industrial application in gas separation.Thus,the energy consumption and operating cost will be further reduced in the ethylene production process.We believe that this shaping method will open a prosperous route to the development of MOFs toward higher technology levels and their commercial application.

Stable titanium metal-organic framework with strong binding affinity for ethaneremoval

Direct separation of high purity ethylene(C_(2)H_(4))from an ethane(C_(2)H_(6))/ethylene mixture is a critical and challenging task owing to the very similar molecular size and physical properties of the two components.While some studies have attempted this separation,there is a lack of excellent porous materials with strong binding affinity for C_(2)H_(6)-selective adsorption via an energy-efficient adsorptive separation process.Herein,we report a titanium metal-organic framework with strong binding affinity and excellent stability for the highly efficient removal of C_(2)H_(6) from C_(2)H_(6)/C_(2)H_(4) mixtures.Single component adsorption isotherms demonstrated a larger amount of adsorbed ethane(1.16 mmol·g^(-1) under 1 kPa)and high C_(2)H_(6)/C_(2)H_(4) selectivity(2.7)for equimolar C_(2)H_(6)/C_(2)H_(4) mixtures,especially in the low-pressure range,which is further confirmed by the results of grand canonical Monte Carlo simulations for C_(2)H_(6) adsorption in this framework.The experimental breakthrough curves showed that C_(2)H_(4) with a high purity was collected directly from both 1:9 and 1:15 C_(2)H_(6)/C_(2)H_(4)(volume ratio)mixtures at 298 K and 100 kPa.Moreover,the unchanged adsorption and separation performance after cycling experiments confirmed the promising applicability of this material in future.

Round-the-clock water harvesting from dry air using a metal-organic framework

Harvesting water from the atmosphere is an important process to solve the extreme lack of water resources in arid regions. Adsorption-based atmospheric water harvesting(AWH) takes advantage of solar thermal energy to harvest water from air. This technique is particularly suitable for arid regions characterized by low humidity and an abundance of sunshine. Nonetheless, under low humidity conditions, AWH is highly dependent on water-adsorbing materials exhibiting excellent performance. In this work, a metal–organic framework(MOF), namely [Zn_(2)(bpy)(btec)(H_(2)O)_(2)]·2H_(2)O, also denoted as MWH-1, was investigated for application in water harvesting under low humidity conditions(<20%). Notably,MWH-1 displayed outstanding water and thermal stability. At temperatures of 293–333 K and low pressure, activated MWH-1a exhibited competitive water uptake(relative humidity(RH) = 5%,uptake>200 cm^(3)·cm^(-3);RH = 10%, uptake >250 cm^(3)·cm^(-3)). This ensured effective water harvesting at high temperatures during the day. In situ powder X-ray diffraction and Fourier-transform infrared analyses confirmed the sensitive water adsorption process of MWH-1a. The X-ray single-crystal study further demonstrated that single-crystal structures could be completely restored following water harvesting.MWH-1 showed good structural stability and enabled water harvesting under low humidity and high temperature conditions. Thus, it has the potential for application in round-the-clock water harvesting in extremely arid regions.

Enhanced ethane/ethylene separation based on metal regulation in zeolitic imidazolate frameworks

The acquisition of polymer-grade(≥99.95%)C_(2)H_(4) poses a challenge due to the presence of ethane(C_(2)H_(6))having similar physical and chemical properties.Consequently,the one-step purification of C_(2)H_(4) becomes a crucial and demanding process.In this study,we synthesized ZIF-78 with a GME configuration using different metal sources(Zn,Co).Both substances have been identified as ethane-selective adsorbents with excellent thermal stability.The Brunauer Emmett Teller(BET)surface area of ZIF-78-Co(748 m^(2)/g)surpasses that of ZIF-78-Zn(585 m^(2)/g),and the former exhibits a higher Q_(st) value for C_(2)H_(6),resulting in enhanced adsorption capacity for C_(2)H_(6)(50.61 cm^(3)/g)and selectivity for C_(2)H_(6)/C_(2)H_(4)(1.71)compared to ZIF-78-Zn(48.97 cm^(3)/g,1.46)at 298 K and 1 bar.Grand Canonical Monte Carlo(GCMC)calculations indicate that C_(2)H_(6) has a stronger interaction with the ZIF-78-Co framework.Breakthrough experiments for the C_(2)H_(6)/C_(2)H_(4)(50:50,V/V)mixture at 298 K and 1 bar demonstrate that ZIF-78-Co achieves separation in approximately 5 min/g,outperforming ZIF-78-Zn.And the separation time for ZIF-78-Co in the C_(2)H_(6)/C_(2)H_(4)(10:90,V/V)mixture is 9 min/g.Furthermore,ZIF-78-Co exhibits excellent structural stability,thermal stability,water stability,and acid-base stability.Therefore,it holds promising prospects for practical industrial separation.Additionally,we hope that our findings inspire further experimentation on alternative metal ethane adsorbents.

Real-time identification of multiple nanoclusters with a protein nanopore in single-cluster level

It is important and challenging to analyze nanocluster structure with atomic precision.Herein,α-hemolysin nanopore was used to identify nanoclusters at the single molecule level by providing two-dimensional(2D)dwell time–current blockage spectra and translocation event frequency which sensitively depended on their structures.Nanoclusters such as Anderson,Keggin,Dawson,and a few lacunary Dawson polyoxometalates with very similar structures,even with only a two-atom difference,could be discriminated.This nanopore device could simultaneously measure multiple nanoclusters in a mixture qualitatively and quantitatively.Furthermore,molecular dynamics(MD)simulations provided microscopic understandings of the nanocluster translocation dynamics and yielded 2D dwell time–current blockage spectra in close agreement with experiments.The nanopore platform provides a novel powerful tool for nanocluster characterization.