Gas Separation Hot Paper

Wiggling Mesopores Kinetically Amplify the Adsorptive Separation ofPropylene/PropaneYa-Fei Yuan+, Yong-Sheng Wang+, Xue-Liang Zhang, Wen-Cui Li, Guang-Ping Hao,* Lu Han,*and An-Hui Lu*

Abstract: Adsorptive separation is an appealing technologyfor propylene and propane separation; however, the challengelies in the design of efficient adsorbents which can distinguishthe two molecules having very similar properties. Here wereport a kinetically amplified separation by creating wigglingmesopores in structurally robust carbon monoliths. Thewiggling mesopores with alternating wide and narrow segmentsafford a surface area of 413 m2 g�1 and a tri-modal pore sizedistribution centered at 1.5, 4.2 and 6.6 nm, respectively. Thesynergistically kinetic and equilibrium effects were observedand quantitatively assessed, which together ensured a remark-able propylene/propane selectivity up to 39. This selectivityoutperformed not only the available carbon adsorbents butalso highly competitive among the dominated crystallineporous adsorbents. In addition, the wiggling mesoporouscarbon adsorbent showed excellent dynamical separationstability, which ensured its great potential in practical molec-ular separations.

The separation of propylene/propane (C3H6/C3H8) is one ofthe most important but challenging processes in the petro-chemical industry because of their intrinsically similar molec-ular sizes (C3H6: 6.5 � 4.0 � 3.8 �3; C3H8: 6.8 � 4.2 � 3.8 �3)and boiling points (C3H6: 225.4 K; C3H8: 231.1 K). Thecurrent separation technique mainly relies on energy-inten-sive cryogenic distillations. Adsorption separation is a prom-ising alternative due to its significantly reduced energyconsumption for the adsorbed phase recovery. While theprerequisite is to develop adsorbent materials that can

distinguish the subtle difference in adsorption affinity and/or diffusion rate between C3H6 and C3H8.

[1]

In principle, precise regulation of micropore sizes andgeometries are the key to maximize the separation factor andcapacity. In thermodynamic equilibrium separation, theadsorbent materials often contain strong binding sites suchas open metal centers to selectively trap C3H6 via p-complex-ation interactions,[2] thus enabling a competitive adsorptioncapacity and equilibrium selectivity. However, the relativelystrong interactions require large energy consumption torecover C3H6 from the adsorbent. Besides, the undesirableolefin polymerization would occur during high-temperaturerecovery.[3] Additionally, due to the limited number of bindingsites, the adsorption capacity for C3H6 is not high, usuallylower than 1.5 mmolg�1.[4] Alternatively, the kinetic separa-tion relies on different diffusion rates of adsorbates travelingthrough the adsorbents� internal pores and allows an energy-efficient recovery.[5]

Following these principles, a number of crystalline poroussolids such as zeolites (DDR, 4A, etc.) and MOFs haveproven to be appealing adsorbents.[6] However, the practicaldrawbacks of these materials are their moisture instabilityand powdery form. In contrast, a handful of microporouscarbon materials, e.g., carbon molecular sieve (CMS) with theinert surface can separate C3H6 from C3H8 and require lessactivation and regeneration energy.[7] However, the gasdiffusion in the highly tortuous ultramicropores is suppressed,thus the adsorption capacity and kinetics need to beenhanced. Enlarging pore sizes to mesopores i.e., 2 nm andabove could greatly increase the adsorption capacity anddiffusion kinetics for both C3H6 and C3H8, but unfortunatelytheir selectivity is almost lost. To date, a plethora ofmesoporous carbon materials can be prepared,[8] howeverbarely any C3H6/C3H8 separation performance can bereached. Experimental and computational findings demon-strated that molecular transport kinetics in the porousmedium is directly relevant to pore geometries in terms ofpore shapes, tortuosity as well as connectivity.[9] This moti-vated us to explore the possibility of kinetically enhancedseparation by the pore geometry engineering at mesoscale.

Herein, we report on a new type of stable carbon monolithwith unique wiggling mesopores (MC-wiggle), which aresynthesized by perturbing the well-organized micelle tem-plate with the binary molecular regulator of boric acid andammonia. The wiggling transport magnified the C3H6/C3H8

kinetic selectivity, and the 0.5 nm centered ultramicroporesenhanced the equilibrium selectivity, which together ensureda remarkable selectivity up to 39, outperforming both thenon-wiggling counterpart (MC, 2.0, 298 K) and common

[*] Y.-F. Yuan,[+] Y.-S. Wang,[+] Prof. W.-C. Li, Prof. G.-P. Hao, Prof. A.-H. LuState Key Laboratory of Fine Chemicals, Liaoning Key Laboratory forCatalytic Conversion of Carbon Resources, and School of ChemicalEngineering, Dalian University of TechnologyDalian 116024 (P. R. China)E-mail: guangpinghao@dlut.edu.cn

anhuilu@dlut.edu.cn

X.-L. ZhangSchool of Chemistry and Chemical Engineering, State Key Laboratoryof Composite Materials, Shanghai Key Laboratory for MolecularEngineering of Chiral Drugs, Shanghai Jiao Tong University800 Dongchuan Road, Shanghai (P. R. China)

X.-L. Zhang, Prof. L. HanSchool of Chemical Science and Engineering, Tongji University1239 Siping Road, Shanghai, 200092 (P. R. China)E-mail: luhan@tongji.edu.cn

[+] These authors contributed equally to this work.

Supporting information and the ORCID identification number(s) forthe author(s) of this article can be found under:https://doi.org/10.1002/anie.202106523.

AngewandteChemieCommunications

How to cite: Angew. Chem. Int. Ed. 2021, 60, 19063–19067International Edition: doi.org/10.1002/anie.202106523German Edition: doi.org/10.1002/ange.202106523

19063Angew. Chem. Int. Ed. 2021, 60, 19063 –19067 � 2021 Wiley-VCH GmbH

mesoporous carbons, e.g., CMK-3 (1.8, 298 K), even is highlycompetitive among the top-performing porous crystallineadsorbents such as zeolites of SiCHA (32, 353 K) and MOFsof Mg-MOF-74 (18.3, 298 K), ZnAtzPO4 (8, 298 K).[10]

The synthesis of MC-wiggle is based on one-step solutionsynthesis (Figure 1a), in which the commercial triblockcopolymer F127 was served as the soft template (Experimen-tal details in Supplementary Information). The amphiphilicF127 above a certain concentration, here is 6 mM, wouldspontaneously form a single disperse phase of thermodynami-cally stable self-associated interfaces at equilibrium. Suchwell-organized micelles were employed to create orderedmesopores with relatively straight pore channels.[11] Here weintentionally broke the continuously soft template intoa discontinuous phase by perturbing the micelle environmentsusing binary molecular regulators of boric acid and ammoniawith a molar ratio of 18. The successive polymerization ofresorcinol and formaldehyde took place around the discon-tinuous micelle templates. Upon pyrolysis, the template wasremoved, leaving the carbon products with wiggling meso-pores (Figure 1a, top). Notably, the F127 micelles sensitivelyresponse to the variations of the perturbing agents, such as themolar ratio and concentration of boric acid and ammonia (seedetails in SI). Consequently, the mesopore geometries can betuned in a wide range (Figure S1).

Interestingly, the perturbing boron-containing species, inthe polymer precursors can be leached out by hot deionized

water at 90 8C, which led to the formation of the controlsample but with non-wiggling features (Figure 1a, below).Morphologically, both the MC-wiggle and MC did not showvisible difference; both were found being composed ofhomogeneously fused sphere-shaped units (Figure S2).

We first assessed the two types of mesopore by the small-angle X-ray scattering (SAXS). A main (100) Bragg reflectionappeared in the SAXS curve, which indicates a regularmesostructure along the (100) direction (Figure 1b). The q forMC-wiggle was down-shifted to 0.56 nm�1 as compared tothat of MC with q of 0.65 nm�1, indicating the presence oflarger lattice spacing for MC-wiggle. The d-spacing calculatedfrom the main (100) reflection is 9.6 and 11.1 nm for MC andMC-wiggle, respectively.

The mesoporous structures were elaborated thoroughlyby gas physisorption based on a series of gas probes withdifferent kinetic sizes including Ar (3.54 �, 87 K, Figure 1c),N2 (3.64 �, 77 K, Figure S3a), H2O (2.64 �, 298 K, Figure 1 e)and toluene (5.85 �, 298 K, Figure S3b). The specific surfacearea was determined to be 413 and 663 m2 g�1 for MC-wiggleand MC, respectively (Table S1). Remarkably, for MC-wiggle,a two-step desorption process was observed for all the gasprobes in terms of Ar, N2, H2O and toluene (Figure 1c,e,Figure S3). The first desorption step is attributed to thecapillary evaporation from open wider mesopores. Thesecond desorption step is relevant to the contracted meso-pores. Based on the state-of-the-art Quenched Solid DensityFunctional Theory (QSDFT) by using Ar desorption branchdata (Figure 1c), a tri-modal pore size distribution (PSD)centered at 1.5, 4.2 and 6.6 nm was obtained for MC-wiggle;while for MC, a main PSD was determined centering at4.4 nm (Figure 1d). These results verified the unique wigglingmesopore feature of MC-wiggle. Notably, this is the firstreport on wiggling mesopores formed in monolithic carbonmaterials.

The detailed porous structure was determined by trans-mission electron microscopy (TEM) investigations. As shownin Figure 1 f, the white contrast indicates the mesopores withlow electron-scattering density. The mesopores are arrangedin a parallel direction with the d-spacing of � 11 nm, which isconsistent with the d-spacing reflection in SAXS analysis. Thenon-uniform TEM contrast of the mesopore channels can beobserved, which indicated the existence of either the discon-tinued mesochannels or the misalignment of the hexagonalmesopores. However, it is difficult to solve the three-dimen-sional (3D) porous structure since the TEM images onlyreveal the two-dimensional (2D) projection of the 3D object.Therefore, the electron tomography was applied to recon-struct the 3D space. As shown in Figure 2a,b and Figure S4,the reconstruction result reveals the outline of the hexagonalpacking of mesochannels. Of note, the discontinued meso-channels with alternating wide and narrow segments can beidentified from the sliced frames, suggesting the wigglingmesopores in the internal structure of MC-wiggle (Figure 2c–e, Video S1). On the other hand, the MC exhibited homoge-neous wormlike mesoporous channels (Video S2), which isconsistent with the single main PSD as shown in gasadsorption results (Figure 1c,d). Based on the above exper-imental evidences, we proposed the two-dimensional geom-

Figure 1. Structural characterizations. (a) Synthesis schematic,(b) SAXS patterns, (c) Ar adsorption isotherms and (d) correspondingpore size distributions, (e) Water adsorption isotherms, (f) TEM imagefor MC-wiggle. The isotherm of MC in (e) offset vertically by10 mmolg�1.

AngewandteChemieCommunications

19064 www.angewandte.org � 2021 Wiley-VCH GmbH Angew. Chem. Int. Ed. 2021, 60, 19063 –19067

etry with alternating mesopores of different sizes, as shown inFigure 2 f. Accordingly, we speculate that the evident surfacefluctuations on the mesopore walls might result in wigglingtransport behavior as guest molecules passing through, whichis different from the free transport in the mesopores withmonomodal PSD (Figure 2 f).

Next, we analyzed the PSD of micropores by CO2

adsorption at 273 K. Both the MC and MC-wiggle displayedessentially the same ultramicroporous pore size that centeredat 0.5 nm (Figure 3a), indicating that the mesoscale perturb-ance barely affected the microporous structure. To unveil theorigin of the wiggling mesopores, we recorded the X-raydiffraction (XRD) patterns to check whether the discontin-ued pore geometry was stemmed from blockage of boron-doped nanoparticles derived from thermal treatment of theB-containing species. Both two samples revealed two diffrac-tion peaks at 2q of 238 and 438 (Figure 3b), which belong to(002) and (101) planes of carbon materials. No diffractionpeaks for boron oxide crystallites were detected in MC-wiggle, indicating that the boron species were either highlydispersed in the carbon-dominated skeletons or completelydecomposed during carbonization. The 11B magic-anglespinning nuclear magnetic resonance (NMR) spectrum andX-ray photoelectron spectroscopy (XPS) spectra of MC-wiggle evidenced the existence of B-species (Table S1), andthe B-doping environment is mainly in the form of B-O-B and

B-O-C (Figure S5, S6). This confirmed the highly dispersed B-doping feature for MC-wiggle.

To assess its potential for C3H6 and C3H8 separation, wefirst investigated the MC-wiggle�s kinetic adsorption charac-teristics by measuring time-resolved gas adsorption perfor-mance and compared them with the non-wiggling counterpartof MC (Figure 3 c). The kinetic study showed that thediffusion rate on MC-wiggle for C3H8 and C3H6 was reducedcompared with MC due to the wiggling transport behavior.While, the diffusion difference between C3H6 and C3H8 wasclearly enlarged, indicating the strong dependence of themolecular transport on the pore geometries. To quantify thekinetic selectivity of MC-wiggle, the diffusional time con-stants for C3H6 and C3H8 were calculated to be 4.2 � 10�3 and2.1 � 10�4, respectively (Figure 3d). The calculated kineticselectivity reached 20 for MC-wiggle, which is 6.1 timeshigher than that of MC. Moreover, the MC-wiggle exhibitedhigh selectivity at equilibrium conditions, together witha C3H6 uptake of 2.6 mmol g�1 at 1 bar (Figure 3e). TheHenry�s selectivity was calculated to be 8.8 for MC-wiggle,but only 1.1 for MC (Figure S7), indicating the preferentialadsorption of C3H6 over MC-wiggle. To understand whetherthe adsorption affinity stems from the interactions of B-species with the C3H6. We explored the mesoporous carbonsof CMK-3 and non-wiggling MC and their B-doped counter-parts for C3H6 and C3H8 adsorption, and no visible enhance-ment was observed for the B-doped carbons (Figure S8).

Figure 2. (a,b) Projection of reconstructed 3D volume by electrontomography and (c–e) the cross-sectional snapshots from video ofMC-wiggle. Scale bar: 100 nm, (f) The proposed two-dimensionalgeometry with alternating mesopores of different sizes and monomo-dal mesopores, as well as possible gas transport behaviors in straightand wiggling mesopores.

Figure 3. (a) CO2 adsorption isotherms and pore size distributions(inset), (b) XRD patterns, (c) Time-resolved adsorption profiles forC3H6/C3H8 at 298 K and (d) corresponding fitting of diffusional timeconstants, (e) C3H6/C3H8 adsorption isotherms of MC-wiggle and MCat 298 K, (f) Illustration of the proposed selective adsorption of C3H6/C3H8 in wiggling mesopores.

AngewandteChemieCommunications

19065Angew. Chem. Int. Ed. 2021, 60, 19063 –19067 � 2021 Wiley-VCH GmbH www.angewandte.org

We further compared the performance parameters includ-ing adsorption capacity, selectivity etc. with the available best-performing adsorbents (Table S2, S3). As shown, our MC-wiggle is highly competitive among the carbonaceous adsorb-ents. Furthermore, the absorption ratio of C3H6/C3H8 reached1.63 at 1 bar and 298 K on MC-wiggle, exceeding the availableC3H6/C3H8 adsorbent benchmarks such as SIFSIX-2-Cu-i (1.59, 298 K), MAF-23-O (1.35, 298 K), Cu(0.6)@MIL-100(Fe) (1.34, 303 K), Co2(m-dobdc) (1.25, 318 K).[12]

Although the selectivity of the MC-wiggle is still lower thanthe state-of-the-art crystalline MOFs and ZIFs,[13] MC-wigglerepresents a new adsorbent model based on mesoporegeometry engineering for C3H6/C3H8 kinetic separation. Asshown in Figure 3 f, we propose that C3H8 molecules withhigher molecular mass and larger dimensions were readily tocollide with the geometrical bulges, and bounce back,resulting in a significant reduction of the diffusion rate inMC-wiggle. While, the smaller propylene molecules were lessaffected, thus magnifying the kinetic selectivity. Bocquet et al.found that the geometrical bulges in nanopores can inducea slowing down via entropic trapping, which is also a usefulclue to explain this kinetic effect.[14a] Similar constraineddiffusion behaviors of guest heparin molecules were observedon mesoporous silica with similar plugged mesoporouschannels.[14b,c] The combined equilibrium-kinetic C3H8/C3H6

selectivity of MC-wiggle is calculated to be � 39 (Figure 4a),

which is far superior to the well-known mesoporous carbonCMK-3 (1.8, 298 K), commercial microporous carbon YP-50(2.1, 298 K), carbon molecular sieve of CMS 4A (5.6, 343 K,Takeda) and CMS-18 (19.5, 303 K), even is in the leadingposition as compared to the top-performing porous crystallineadsorbents, such as zeolites of SiCHA (32, 353 K) and MOFsof Mg-MOF-74 (18.3, 298 K), ZnAtzPO4 (8, 298 K) undersimilar test conditions (Figure S9, S10).[7b,d,10] Meanwhile, theC3H6 uptake reaches 2.6 mmolg�1, which is highly compet-itive among the well-performing adsorbents.

To evaluate the interaction between the adsorbed C3H6

and the pore walls of the adsorbents, we calculated theisosteric heat of adsorption (Qst), based on the Clausius-Clapeyron equation, and compared to a series of availableadsorbents. The MC-wiggle manifests a low Qst of only17 kJ mol�1 at zero C3H6 loading, which is significantly lowerthan many crystalline adsorbents including Fe-MOF-74(44 kJ mol�1), Y-abtc (50 kJmol�1), KAUST-7 (57 kJmol�1)and Mg-MOF-74 (61 kJ mol�1) (Figure 4b, Figure S11).[10b,13]

Such low Qst is attributed to the synergistically kinetic andequilibrium effects, which ensured an energy-efficient regen-eration. The temperature-programmed desorption profiles(Figure 4c), in situ FT-IR spectra (Figure 4d, Figure S12) aswell as the time-resolved desorption experiments (Fig-ure S13) confirmed that the regeneration of MC-wiggle canbe achieved at room temperature by inert gas purging or bydegassing to a vacuum of 2 mbar, evidencing its easy recovery.

Furthermore, the breakthrough experiments with the feedof mixtures of C3H6/C3H8 (50/50 v/v) were conducted underdynamic conditions (Figure S14). The breakthrough curvesare shown in Figure 4 e. For MC-wiggle, the breakthroughpoints of C3H8 (0.52 mmolg�1) are much earlier than that ofC3H6 (1.58 mmolg�1). While, on MC, both the C3H6 and C3H8

penetrate the adsorbent bed almost at the same time.Additionally, the wiggling mesoporous carbon displays anobvious “roll-up” effect, indicating the competitive adsorp-tion of C3H6 over C3H8 in the ultramicropores. Besides,breakthrough cycling tests reveal that MC-wiggle can retainmore than 98 % of its separation capability, with the break-through time being almost unchanged in successive multi-cycles (Figure 4 f, Figure S15).

In summary, creating wiggling mesopores in monolithiccarbon adsorbents has been demonstrated as an appealingstrategy for effective C3H6/C3H8 separation, which representsa fresh idea in designing new porous adsorbents. Theinvestigation of the generality of the synthesis for mesoporousmaterials with surface fluctuations is on the way; we are alsocollaborating with molecular dynamics simulation professio-nals aiming to unveil the detailed separation mechanism,which could potentially deepen theoretical understanding onthe kinetic separation. The targeted modification of thetransport channels at nanoscale enabled the local and globalcontrol of diffusion behaviors of adsorbed molecules, whichwould lead to a high-performance in the fields of gasadsorption separation, confined catalytic reactions, drugdelivery and release, etc.

Figure 4. (a) Plot of combined equilibrium-kinetic C3H6/C3H8 selectivityagainst C3H6 adsorption capacity of MC-wiggle and MC and thecomparison with the reported[7b,d, 10] and experimentally synthesizedbenchmarks, (b) Heat of adsorption, Qst at zero C3H6 loading on MC-wiggle and other adsorption benchmarks,[10b,c,12a,13] (c) TPD profiles ofC3H6 for MC-wiggle, (d) In situ FT-IR spectra of MC-wiggle duringpulsed adsorption of C3H6. (e) Breakthrough curves and (f) break-through cycling test for gas feed of equimolar binary mixture of C3H6/C3H8 with a flow rate of 2 mLmin�1 under ambient conditions.

AngewandteChemieCommunications

19066 www.angewandte.org � 2021 Wiley-VCH GmbH Angew. Chem. Int. Ed. 2021, 60, 19063 –19067

Acknowledgements

The research was financially supported by the NationalNatural Science Foundation for Distinguished Young Schol-ars (No. 21225312), the National Natural Science Foundationof China (21975037; 21922304), the Cheung Kong ScholarsProgram of China (T2015036), and the FundamentalResearch Funds for the Central Universities (DUT20GJ215,DUT18RC(3)075), Liao Ning Revitalization Talents Program(XLYC1807205).

Conflict of Interest

The authors declare no conflict of interest.

Keywords: adsorption separation · C3H6/C3H8 separation ·carbon monoliths · self-assembly ·wiggling mesoporous carbons

[1] a) D. S. Sholl, R. P. Lively, Nature 2016, 532, 435 – 437; b) J. Y. S.Lin, Science 2016, 353, 121 – 122; c) Y. Wang, S. B. Peh, D. Zhao,Small 2019, 15, 1900058.

[2] a) Y. S. Bae, C. Y. Lee, K. C. Kim, O. K. Farha, P. Nickias, J. T.Hupp, S. T. Nguyen, R. Q. Snurr, Angew. Chem. Int. Ed. 2012, 51,1857 – 1860; Angew. Chem. 2012, 124, 1893 – 1896; b) D. Saha, B.Toof, R. Krishna, G. Orkoulas, P. Gismondi, R. Thorpe, M. L.Comroe, Microporous Mesoporous Mater. 2020, 299, 110099;c) J. W. Yoon, A. R. Kim, M. J. Kim, T. U. Yoon, J. H. Kim, Y. S.Bae, Microporous Mesoporous Mater. 2019, 279, 271 – 277;d) D. J. Safarik, R. B. Eldridge, Ind. Eng. Chem. Res. 1998, 37,2571 – 2581.

[3] a) L. Li, R. B. Lin, X. Wang, W. Zhou, L. Jia, J. Li, B. Chen,Chem. Eng. J. 2018, 354, 977 – 982; b) P. Ji, J. B. Solomon, Z. Lin,A. M. Wilders, R. F. Jordan, W. Lin, J. Am. Chem. Soc. 2017, 139,11325 – 11328.

[4] a) Y. Chai, X. Han, W. Li, S. Liu, S. Yao, C. Wang, W. Shi, I. da-Silva, P. Manuel, Y. Cheng, L. D. Daemen, A. J. Ramirez-Cuesta,C. C. Tang, L. Jiang, S. Yang, N. Guan, L. Li, Science 2020, 368,1002 – 1006; b) F. Iucolano, P. Aprea, D. Caputo, C. Colella, M.Eic, Q. Huang, Adsorption 2008, 14, 241 – 246.

[5] a) J. Peng, H. Wang, D. H. Olson, Z. Li, J. Li, Chem. Commun.2017, 53, 9332 – 9335; b) K. Li, D. H. Olson, J. Seidel, T. J. Emge,H. Gong, H. Zeng, J. Li, J. Am. Chem. Soc. 2009, 131, 10368 –10369.

[6] a) H. Wang, Y. Liu, J. Li, Adv. Mater. 2020, 32, 2002603; b) W. G.Cui, T. L. Hu, X. H. Bu, Adv. Mater. 2020, 32, 1806445; c) Y.Chen, Z. Qiao, D. Lv, C. Duan, X. Sun, H. Wu, R. Shi, Q. Xia, Z.Li, Chem. Eng. J. 2017, 328, 360 – 367.

[7] a) J. Liu, J. Goss, T. Calverley, Y. Liu, C. Broomall, J. Kang, R.Golombeski, D. Anaya, B. Moe, K. Mabe, G. Watson, A. Wetzel,Microporous Mesoporous Mater. 2020, 305, 110341; b) J. Liu,E. M. Calverley, M. H. McAdon, J. M. Goss, Y. Liu, K. C.Andrews, T. D. Wolford, D. E. Beyer, C. S. Han, D. A. Anaya,R. P. Golombeski, C. F. Broomall, S. Sprague, H. Clements, K. F.Mabe, Carbon 2017, 123, 273 – 282; c) J. Liu, Y. Liu, D. K. Talay,E. Calverley, M. Brayden, M. Martinez, Carbon 2015, 85, 201 –211; d) C. A. Grande, V. M. Silva, C. Gigola, A. E. Rodrigues,Carbon 2003, 41, 2533 – 2545; e) S. Du, X. Wang, J. Huang, K.Kent, B. Huang, I. Karam, Z. Li, J. Xiao, AIChE J. 2021, e17285.

[8] a) M. Mofarahi, M. Sadrameli, J. Towfighi, J. Chem. Eng. Data2003, 48, 1256 – 1261; b) C. Selzer, A. Werner, S. Kaskel, Ind.Eng. Chem. Res. 2018, 57, 6609 – 6617; c) M. Perovica, S. S.

Alonib, Y. Mastaib, M. Oschatz, Carbon 2020, 170, 550 – 557;d) M. Perovic, Q. Qin, M. Oschatz, Adv. Funct. Mater. 2020, 30,1908371.

[9] a) P. J. Bereciartua, �. Cant�n, A. Corma, J. L. Jord�, M.Palomino, F. Rey, S. Valencia, E. W. Corcoran, Jr., P. Kortunov,P. I. Ravikovitch, A. Burton, C. Yoon, Y. Wang, C. Paur, J.Guzman, A. R. Bishop, G. L. Casty, Science 2017, 358, 1068 –1071; b) A. Z�rner, J. Kirstein, M. Dçblinger, C. Bruchle, T.Bein, Nature 2007, 450, 705 – 708; c) S. Mukherjee, D. Sen-sharma, K. J. Chen, M. J. Zaworotko, Chem. Commun. 2020, 56,10419 – 10441; d) Q. Ding, Z. Zhang, C. Yu, P. Zhang, J. Wang, X.Cui, C. H. He, S. Deng, H. Xing, Sci. Adv. 2020, 6, eaaz4322;e) Y. Zhang, L. Yang, L. Wang, S. Duttwyler, H. Xing, Angew.Chem. Int. Ed. 2019, 58, 8145 – 8150; Angew. Chem. 2019, 131,8229 – 8234.

[10] a) M. Khalighi, Y. F. Chen, S. Farooq, I. A. Karimi, J. W. Jiang,Ind. Eng. Chem. Res. 2013, 52, 3877 – 3892; b) Z. Bao, S.Alnemrat, L. Yu, I. Vasiliev, Q. Ren, X. Lu, S. Deng, Langmuir2011, 27, 13554 – 13562; c) Q. Ding, Z. Zhang, C. Yu, P. Zhang, J.Wang, L. Kong, X. Cui, C. H. He, S. Deng, H. Xing, AIChE J.2020, e17094.

[11] a) S. Xu, W.-C. Li, C.-T. Wang, L. Tang, G.-P. Hao, A. H. Lu,Angew. Chem. Int. Ed. 2021, 60, 6339 – 6343; Angew. Chem.2021, 133, 6409 – 6413; b) L. Peng, H. Peng, C.-T. Hung, D. Guo,L. Duan, B. Ma, L. Liu, W. Li, D. Zhao, Chem 2021, 7, 1020 –1032; c) J. Wang, Y. Xu, B. Ding, Z. Chang, X. Zhang, Y.Yamauchi, K. C. W. Wu, Angew. Chem. Int. Ed. 2018, 57, 2894 –2898; Angew. Chem. 2018, 130, 2944 – 2948; d) H. Xiong, H.Zhou, G. Sun, Z. Liu, L. Zhang, L. Zhang, F. Du, Z.-A. Qiao, S.Dai, Angew. Chem. Int. Ed. 2020, 59, 11053 – 11060; Angew.Chem. 2020, 132, 11146 – 11153; e) T. Wang, F. Okejiri, Z.-A.Qiao, S. Dai, Adv. Mater. 2020, 32, 2002475; f) T. Zhao, A.Elzatahry, X. Li, D. Zhao, Nat. Rev. Mater. 2019, 4, 775 – 791.

[12] a) X. Wang, P. Zhang, Z. Zhang, L. Yang, Q. Ding, L. Cui, J.Wang, H. Xing, Ind. Eng. Chem. Res. 2020, 59, 3531 – 3537; b) Y.Wang, N. Y. Huang, X. W. Zhang, H. He, R. K. Huang, Z. M. Ye,Y. Li, D. D. Zhou, P. Q. Liao, X. M. Chen, J. P. Zhang, Angew.Chem. Int. Ed. 2019, 58, 7692 – 7696; Angew. Chem. 2019, 131,7774 – 7778; c) A. R. Kim, T.-U. Yoon, E.-J. Kim, J. W. Yoon, S.-Y. Kim, J. W. Yoon, Y. K. Hwang, J.-S. Chang, Y.-S. Bae, Chem.Eng. J. 2018, 331, 777 – 784; d) J. E. Bachman, M. T. Kapelewski,D. A. Reed, M. I. Gonzalez, J. R. Long, J. Am. Chem. Soc. 2017,139, 15363 – 15370.

[13] a) S. Schmittmann, C. Pasel, M. Luckas, D. Bathen, J. Chem.Eng. Data 2020, 65, 706 – 716; b) C. A. Grande, J. D. P. Araujo, S.Cavenati, N. Firpo, E. Basaldella, A. E. Rodrigues, Langmuir2004, 20, 5291 – 5297; c) A. Cadiau, K. Adil, P. M. Bhatt, Y.Belmabkhout, M. Eddaoudi, Science 2016, 353, 137 – 140; d) B.Liang, X. Zhang, Y. Xie, R. B. Lin, R. Krishna, H. Cui, Z. Li, Y.Shi, H. Wu, W. Zhou, B. Chen, J. Am. Chem. Soc. 2020, 142,17795 – 17801; e) C. A. Grande, A. E. Rodrigues, Ind. Eng.Chem. Res. 2004, 43, 8057 – 8065; f) J. W. Yoon, I. T. Jang, K. Y.Lee, Y. K. Hwang, J. S. Chang, Bull. Korean Chem. Soc. 2010, 31,220 – 223; g) H. Wang, X. Dong, V. Colombo, Q. Wang, Y. Liu,W. Liu, X. L. Wang, X. Y. Huang, D. M. Proserpio, A. Sironi, Y.Han, J. Li, Adv. Mater. 2018, 30, 1805088.

[14] a) S. Marbach, D. S. Dean, L. Bocquet, Nat. Phys. 2018, 14,1108 – 1113; b) M. M. Wan, W. J. Qian, W. G. Lin, Y. Zhou, J. H.Zhu, J. Mater. Chem. B 2013, 1, 3897 – 3905; c) V. Cauda, L.M�hlstein, B. Onida, T. Bein, Microporous Mesoporous Mater.2009, 118, 435 – 442.

Manuscript received: May 15, 2021Revised manuscript received: June 13, 2021Accepted manuscript online: June 18, 2021Version of record online: July 19, 2021

AngewandteChemieCommunications

19067Angew. Chem. Int. Ed. 2021, 60, 19063 –19067 � 2021 Wiley-VCH GmbH www.angewandte.org