Dynamic molecular pockets on diffusion channel for efficient production of polymer-grade propylene

Dynamic molecular pockets on diffusion channel for efficient production of polymer-grade propylene | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Physical Sciences - Article Dynamic molecular pockets on diffusion channel for efficient production of polymer-grade propylene Dan Li, Heng Zeng, Ting Wang, Mo Xie, Rong-Jia Wei, Xiao-Jing Xie, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-222860/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted You are reading this latest preprint version Abstract Size-based molecular sieving works well for rigid molecules with complete exclusion of larger ones, yet interaction-induced molecular sieving may offer unusual separation capability for molecules with matching physicochemical properties. Here we report a MOF material (XXU-3) featuring one-dimension channels with embedded molecular pockets opening to C3H6 and C3H8 at substantially different pressures. The dynamic nature of the pockets is revealed by single-crystal-to-single-crystal transformation upon exposure of the activated XXU-3 to C3H6 or C3H8 atmosphere. Breakthrough experiments demonstrate that XXU-3 is not only capable of separating C3H6 from C3H8 with record-high C3H6 productivity, but also the first MOF material realizing polymer-grade C3H6 production in a single adsorption-desorption cycle from an equimolar C3H6/C3H8 mixture. The underlying separation mechanism, namely orthogonal-array dynamic molecular sieving, is an exemplary strategy for both large separation capacity and fast adsorption-desorption kinetics. This work presents an ideal design for next-generation sieving materials and it holds great potential for applications in adsorptive separation. Materials Chemistry Organic Chemistry polymer-grade propylene sieving materials Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Full Text Additional Declarations There is NO Competing Interest. Supplementary Files SupplementaryInformationDB.pdf Dynamic molecular pockets on diffusion channel for efficient production of polymer-grade propylene Cite Share Download PDF Status: Under Review Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-222860","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Physical Sciences - Article","associatedPublications":[],"authors":[{"id":11862960,"identity":"02e389e7-402d-4e92-bf3f-c4c8eb1ab77e","order_by":0,"name":"Dan Li","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAvklEQVRIiWNgGAWjYBACewYGxgMJFWxgjgRRWgwbGBgOJJwhRYvBAaAWxjYGUrQcP3vgwMN5fHkGB5gP3uZhsMsjrOVMXsKBxG1sxQYH2JKteRiSi4lwWI4BSEvihgM8ZtI8DAcSGwhqOf8GqGUOSAv/NyK13ADZ0gC2hY04LYYzgLYkHGNLnHmYzdhyjkEyYS32/DmGD3/UHEvsO9788MabCjvCWqDgGAMDM9idRKoHghrilY6CUTAKRsHIAwDDrkDNk/QdjQAAAABJRU5ErkJggg==","orcid":"https://orcid.org/0000-0002-4936-4599","institution":"Jinan University","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Dan","middleName":"","lastName":"Li","suffix":""},{"id":11862961,"identity":"e1a20174-9e59-4c88-ac6f-53778912440e","order_by":1,"name":"Heng Zeng","email":"","orcid":"","institution":"Jinan University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Heng","middleName":"","lastName":"Zeng","suffix":""},{"id":11862962,"identity":"78d8af50-ed4a-4572-b286-aabebfaad954","order_by":2,"name":"Ting Wang","email":"","orcid":"","institution":"Jinan University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Ting","middleName":"","lastName":"Wang","suffix":""},{"id":11862963,"identity":"9d3bc461-0d57-42d0-9d79-7add81c66e90","order_by":3,"name":"Mo Xie","email":"","orcid":"","institution":"Jinan University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Mo","middleName":"","lastName":"Xie","suffix":""},{"id":11862964,"identity":"560b55a7-c65e-4ca4-99a6-b33771b1a361","order_by":4,"name":"Rong-Jia Wei","email":"","orcid":"","institution":"Jinan University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Rong-Jia","middleName":"","lastName":"Wei","suffix":""},{"id":11862965,"identity":"e8128603-17a2-4313-95b3-2f464f19d75e","order_by":5,"name":"Xiao-Jing Xie","email":"","orcid":"","institution":"Jinan University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Xiao-Jing","middleName":"","lastName":"Xie","suffix":""},{"id":11862966,"identity":"abc116e4-dfa9-47bb-9f3a-d3040c135b88","order_by":6,"name":"Yifang Zhao","email":"","orcid":"","institution":"Jinan University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Yifang","middleName":"","lastName":"Zhao","suffix":""},{"id":11862967,"identity":"3d4a44ad-7f75-410e-a705-54e463d3fc80","order_by":7,"name":"Weigang Lu","email":"","orcid":"https://orcid.org/0000-0001-9751-8241","institution":"Jinan University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Weigang","middleName":"","lastName":"Lu","suffix":""}],"badges":[],"createdAt":"2021-02-08 12:51:02","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-222860/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-222860/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":5993028,"identity":"8d83d775-385d-4267-bc03-29429ffb7a20","added_by":"auto","created_at":"2021-02-15 23:43:03","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":135720,"visible":true,"origin":"","legend":"Crystal structure of XXU-3. (a) Pore structure viewed along the b axis showing molecular pockets (turquoise) and one-dimension channel (yellow). (b) Cross-sectional view of Connolly surface of the void in (a), where a probe radius of 0.8 Å was used to visualize the molecular pockets opening to the one-dimension channel. (c) Close-up view of the “gourd-shaped” aperture connecting the pocket to the channel. Color code: light blue, Co; red, O; blue, N; white, H; grey, C atoms. H atom is omitted in (a) for clarity.","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-222860/v1/0ded04f4f4f52a91d5baecb4.jpg"},{"id":5992811,"identity":"4130af6e-8866-489a-8e56-2cbb0374d6af","added_by":"auto","created_at":"2021-02-15 23:39:58","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":226919,"visible":true,"origin":"","legend":"Gas sorption properties and DSC profiles. (a) Low-pressure Ar adsorption/desorption isotherms of XXU-3a at 87 K. (inset) calculated pore-size distribution of XXU-3a based on the adsorption branch. (b) C3H6 adsorption isotherms of XXU-3a at different temperatures. (c) C3H8 adsorption isotherms of XXU-3a at different temperatures. (d) Pure C3H8 (green), pure C3H6 (red), and an equimolar mixture of C3H6/C3H8 (orange) adsorption/desorption isotherms of XXU-3a at 303 K. For the equimolar mixture, the x-axis is partial pressure of C3H6. (e) Differential scanning calorimetry of C3H6 and 50/50 C3H6/He adsorption and desorption on XXU-3a at 303 K and 1 bar. (f) Differential scanning calorimetry of C3H8 and 50/50 C3H8/He adsorption and desorption on XXU-3a at 303 K and 1 bar. In (e) and (f), the adsorption was carried out under C3H6, C3H8, or 50/50 mixed-component (C3H6/He and C3H8/He) at a flow rate of 5.0 mL min-1. The desorption was carried out under helium at a flow rate of 5.0 mL min-1 starting at 15-min time point.","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-222860/v1/c324b2a9f33fe15ec2e0dfd8.jpg"},{"id":5993030,"identity":"da69796e-5b77-4338-b031-6dc4121acdaf","added_by":"auto","created_at":"2021-02-15 23:43:03","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":274164,"visible":true,"origin":"","legend":"Binding sites and dynamic gate-opening. (a) Crystal structure of C3H6@XXU-3a viewed along the b axis highlighting the pocket-occupying C3H6 molecules. (b) Connolly surface representation of C3H6@XXU-3a along the b axis with the adsorbed C3H6 molecules. (c) Close-up view of C3H6 in the single crystal of C3H6@XXU-3a, showing multiple interactions with surrounding linkers on the pocket. C3H6 molecules are shown in a space-filling model depicted in violet, and distances are in Å. (d) Crystal structure of C3H8@XXU-3a viewed along the b axis highlighting the pocket-occupying C3H8 molecules. (e) Connolly surface representation of C3H8@XXU-3a along the b axis with the adsorbed C3H8 molecules. (f) Close-up view of C3H8 in the single crystal of C3H8@XXU-3a, showing multiple interactions with surrounding organic linkers on the pocket, C3H8 molecules are shown in a space-filling model depicted in orange, and distances are in Å. (g) Connolly surface comparison to illustrate the opening up of the “gourd-shaped” aperture along with the adsorption of C3H6 or C3H8. C3H8 and C3H6 were omitted for clarity. Color code: light blue, red, blue, white, and grey nodes represent Co, O, N, H, and C atoms, respectively. H atom is omitted in (a) and (d) for clarity.","description":"","filename":"3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-222860/v1/e5d6037d0aefa6539e184cd5.jpg"},{"id":5993026,"identity":"13e3d535-3337-4de3-acec-1878c2bd5127","added_by":"auto","created_at":"2021-02-15 23:43:02","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":147422,"visible":true,"origin":"","legend":"DFT calculations. (a) Geometry optimization by density functional theory (DFT) for (i) XXU-3a@2C3H6, full relax the geometry and cell parameters; and (ii) XXU-3a@2C3H6’, fix the geometry and cell parameters. (b) The rotation of the dihedral angle of the pyridine plane and triazole plane. Color code: light blue, red, blue, white, and grey represent Co, O, N, H, and C atoms, respectively. H atom is omitted in (a) for clarity.","description":"","filename":"4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-222860/v1/ae6655e0417144ee3931d522.jpg"},{"id":5993029,"identity":"5a3598dd-b6e7-42af-9eda-8d86d9071851","added_by":"auto","created_at":"2021-02-15 23:43:03","extension":"jpg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":189741,"visible":true,"origin":"","legend":"Breakthrough experiments. Breakthrough curves of an equimolar mixture of C3H6/C3H8 (1.0 mL min-1) on XXU-3a, KAUST-7, and Y-abtc, followed by desorption curves under helium gas (10.0 mL min-1) sweeping at 303 K. C3H8 (open diamonds), C3H6 (solid diamonds). For comparison, the x-axis is normalized to “time per gram adsorbents”. C and C0 are the concentrations of each gas at the outlet and inlet, respectively. Dashed blue lines highlight the gas composition at 99.5 % and 90 %, respectively. Grey area: mixed gas input. Yellow area: C3H6 gas output.","description":"","filename":"5.jpg","url":"https://assets-eu.researchsquare.com/files/rs-222860/v1/db9ef918644af850a9889671.jpg"},{"id":5993045,"identity":"1314c57c-c464-4a53-a193-f56ad2e7bec0","added_by":"auto","created_at":"2021-02-15 23:43:24","extension":"jpg","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":89288,"visible":true,"origin":"","legend":"C3H6 productivity and purity. Comparison of C3H6 productivity and purity estimated from the experimental breakthrough data of an equimolar C3H6/C3H8 mixture on XXU-3a, KAUST-7, and Y-abtc at different flowrates.","description":"","filename":"6.jpg","url":"https://assets-eu.researchsquare.com/files/rs-222860/v1/c476abfcc4ca649800d15fd3.jpg"},{"id":5993027,"identity":"2eb576b0-a63b-4591-ac5d-9b02c4109f12","added_by":"auto","created_at":"2021-02-15 23:43:02","extension":"jpg","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":125263,"visible":true,"origin":"","legend":"Recyclability and breakthrough experiment under humid conditions. (a) C3H6 adsorption on XXU-3a over 50 consecutive adsorption-desorption cycles in a single-component breakthrough experiment at 303 K; desorption was carried out by helium gas sweeping (10 mL min-1) for 15 min. (b) Eight breakthrough curves of XXU-3a for an equimolar C3H6/C3H8 mixture at 303 K and 1 bar. (c) Breakthrough curves for an equimolar mixture of C3H6/C3H8 at a flow rate of 6.0 mL min-1 on XXU-3a under dry and humid conditions (50 % RH), followed by desorption curves under helium gas sweeping (10.0 mL min-1) at 303 K. (d) comparison of C3H6 productivity 99.5 %) in volume per unit mass of adsorbents under 0% RH and 50 % RH conditions.","description":"","filename":"7.jpg","url":"https://assets-eu.researchsquare.com/files/rs-222860/v1/2c42a626ef2d1e21b0e9cf10.jpg"},{"id":13588665,"identity":"d3391655-4162-4d4d-9c76-d06b97a42952","added_by":"auto","created_at":"2021-09-17 04:56:41","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1712430,"visible":true,"origin":"","legend":"Article File","description":"","filename":"ManuscriptDB.pdf","url":"https://assets-eu.researchsquare.com/files/rs-222860/v1_covered.pdf"},{"id":5993025,"identity":"6e9e543c-342e-42f7-acb2-7cc038ffb49f","added_by":"auto","created_at":"2021-02-15 23:43:02","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1556989,"visible":true,"origin":"","legend":"Article File","description":"","filename":"ManuscriptDB.pdf","url":"https://assets-eu.researchsquare.com/files/rs-222860/v1_stamped.pdf"},{"id":5993031,"identity":"7a3d282b-782f-4fae-a3af-119de4cb2659","added_by":"auto","created_at":"2021-02-15 23:43:03","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":7556305,"visible":true,"origin":"","legend":"Dynamic molecular pockets on diffusion channel for efficient production of polymer-grade propylene","description":"","filename":"SupplementaryInformationDB.pdf","url":"https://assets-eu.researchsquare.com/files/rs-222860/v1/56f90c9bb2b836a06c1275b4.pdf"}],"financialInterests":"There is \u003cb\u003eNO\u003c/b\u003e Competing Interest.","formattedTitle":"Dynamic molecular pockets on diffusion channel for efficient production of polymer-grade propylene","fulltext":[{"header":"Full Text","content":"\u003cp\u003eThis preprint is available for \u003ca href='/article/rs-222860/latest.pdf' target='_blank'\u003edownload as a PDF\u003c/a\u003e.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"nature-portfolio","isNatureJournal":true,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"","title":"Nature Portfolio","twitterHandle":"","acdcEnabled":false,"dfaEnabled":false,"editorialSystem":"ejp","reportingPortfolio":"","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"polymer-grade propylene, sieving materials","lastPublishedDoi":"10.21203/rs.3.rs-222860/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-222860/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"Size-based molecular sieving works well for rigid molecules with complete exclusion of larger ones, yet interaction-induced molecular sieving may offer unusual separation capability for molecules with matching physicochemical properties. Here we report a MOF material (XXU-3) featuring one-dimension channels with embedded molecular pockets opening to C3H6 and C3H8 at substantially different pressures. The dynamic nature of the pockets is revealed by single-crystal-to-single-crystal transformation upon exposure of the activated XXU-3 to C3H6 or C3H8 atmosphere. Breakthrough experiments demonstrate that XXU-3 is not only capable of separating C3H6 from C3H8 with record-high C3H6 productivity, but also the first MOF material realizing polymer-grade C3H6 production in a single adsorption-desorption cycle from an equimolar C3H6/C3H8 mixture. The underlying separation mechanism, namely orthogonal-array dynamic molecular sieving, is an exemplary strategy for both large separation capacity and fast adsorption-desorption kinetics. This work presents an ideal design for next-generation sieving materials and it holds great potential for applications in adsorptive separation.","manuscriptTitle":"Dynamic molecular pockets on diffusion channel for efficient production of polymer-grade propylene","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2021-02-15 23:39:57","doi":"10.21203/rs.3.rs-222860/v1","editorialEvents":[],"status":"published","journal":{"display":false,"email":"[email protected]","identity":"nature","isNatureJournal":true,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"nature","sideBox":"Learn more about [Nature](http://www.nature.com/nature/)","snPcode":"","submissionUrl":"","title":"Nature","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"ejp","reportingPortfolio":"Nature","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"511f40f7-a426-43f5-acc5-53d060d775e8","owner":[],"postedDate":"February 15th, 2021","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[{"id":2431905,"name":"Materials Chemistry"},{"id":2431906,"name":"Organic Chemistry"}],"tags":[],"updatedAt":"2021-03-16T12:23:31+00:00","versionOfRecord":[],"versionCreatedAt":"2021-02-15 23:39:57","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-222860","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-222860","identity":"rs-222860","version":["v1"]},"buildId":"WrCJVZZCHTDjtuVLN7oU0","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}