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Creating hierarchical pores in metal–organic frameworks via postsynthetic reactions

Nature Protocols volume 18, pages 604–625 (2023)Cite this article

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Abstract

Metal–organic frameworks (MOFs) demonstrate promise for a multitude of applications owing to their high porosity and surface area. However, the majority of conventional MOFs possess only micropores with very limited accessibility to substances larger than 2 nm—especially functional biomacromolecules like some proteins. It is challenging to create an appropriately large pore size while avoiding framework collapse in MOFs. Herein, we present the generation of mesopores in microporous MOFs through three facile and effective techniques, namely Soxhlet washing, linker hydrolysis and linker thermolysis. These postsynthetic elimination approaches have been applied in selected MOFs, including PCN-250, PCN-160 and UiO-66, and controllably generate MOFs with hierarchical pores and high stability. Our work demonstrates reproducible and straightforward methods resulting in hierarchically porous materials that possess the benefits of mesoporosity while borrowing the robustness of a micropore framework. All the procedures can be conducted reliably at a multigram scale and operation time less than 6 h, representing a significant effort in the field of MOF synthesis. These hierarchically porous MOFs show great promise in a wide range of applications as efficient adsorbents, catalysts and drug carriers.

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Fig. 1: Schematic illustration of three methodologies introduced in this protocol, namely Soxhlet washing, linker hydrolysis and linker thermolysis.
Fig. 2: The synthesis of the carboxylic ligands utilized in this protocol, all of which can be accomplished at gram scale without column purification.
Fig. 3: Schematic illustrating the synthetic procedures of H4ABTC and PCN-250.
Fig. 4: Schematic illustrating the synthetic procedures of H2AZDC, H2CBAB, PCN-160 and PCN-160-R%.
Fig. 5: Equipment setup for the synthesis of 2.
Fig. 6: Schematic illustrating the synthesis and linker thermolysis of UiO-66-NH2-R%.
Fig. 7: Nitrogen sorption results of PCN-250 before and after Soxhlet washing.
Fig. 8: Nitrogen sorption results of PCN-160-CBAB-R% before and after linker hydrolysis.
Fig. 9: Nitrogen sorption results of UiO-66-NH2-R% before and after treatment under 350 °C.

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Data availability

All the data and figures are available at https://doi.org/10.6084/m9.figshare.c.6012310.v1.

References

  1. Rosi Nathaniel, L. et al. Hydrogen storage in microporous metal–organic frameworks. Science 300, 1127–1129 (2003).

    Article  CAS  Google Scholar 

  2. Li, J.-R., Kuppler, R. J. & Zhou, H.-C. Selective gas adsorption and separation in metal–organic frameworks. Chem. Soc. Rev. 38, 1477–1504 (2009).

    Article  CAS  Google Scholar 

  3. Mason, J. A. et al. Methane storage in flexible metal–organic frameworks with intrinsic thermal management. Nature 527, 357–361 (2015).

    Article  CAS  Google Scholar 

  4. Li, J.-R., Sculley, J. & Zhou, H.-C. Metal–organic frameworks for separations. Chem. Rev. 112, 869–932 (2012).

    Article  CAS  Google Scholar 

  5. Bloch Eric, D. et al. Hydrocarbon separations in a metal–organic framework with open iron(II) coordination sites. Science 335, 1606–1610 (2012).

    Article  CAS  Google Scholar 

  6. Kim, H. et al. Water harvesting from air with metal–organic frameworks powered by natural sunlight. Science 356, 430–434 (2017).

    Article  CAS  Google Scholar 

  7. Liu, J., Xie, D., Shi, W. & Cheng, P. Coordination compounds in lithium storage and lithium-ion transport. Chem. Soc. Rev. 49, 1624–1642 (2020).

    Article  CAS  Google Scholar 

  8. Lee, J. et al. Metal–organic framework materials as catalysts. Chem. Soc. Rev. 38, 1450–1459 (2009).

    Article  CAS  Google Scholar 

  9. Yang, J. & Yang, Y.-W. Metal–organic frameworks for biomedical applications. Small 16, 1906846 (2020).

    Article  CAS  Google Scholar 

  10. Xu, Z., Luo, T. & Lin, W. Nanoscale metal–organic layers for biomedical applications. Acc. Mater. Res. 2, 944–953 (2021).

    Article  CAS  Google Scholar 

  11. Eddaoudi, M. et al. Modular chemistry: secondary building units as a basis for the design of highly porous and robust metal−organic carboxylate frameworks. Acc. Chem. Res. 34, 319–330 (2001).

    Article  CAS  Google Scholar 

  12. Deng, H. et al. Large-pore apertures in a series of metal–organic frameworks. Science 336, 1018–1023 (2012).

    Article  CAS  Google Scholar 

  13. Moghadam, P. Z. et al. Development of a Cambridge Structural Database subset: a collection of metal–organic frameworks for past, present, and future. Chem. Mat. 29, 2618–2625 (2017).

    Article  CAS  Google Scholar 

  14. Moghadam, P. Z. et al. Targeted classification of metal–organic frameworks in the Cambridge Structural Database (CSD. Chem. Sci. 11, 8373–8387 (2020).

  15. Li, H., Eddaoudi, M., O’Keeffe, M. & Yaghi, O. M. Design and synthesis of an exceptionally stable and highly porous metal–organic framework. Nature 402, 276–279 (1999).

    Article  CAS  Google Scholar 

  16. Yaghi, O. M. et al. Reticular synthesis and the design of new materials. Nature 423, 705–714 (2003).

    Article  CAS  Google Scholar 

  17. Gong, Y.-N., Zhong, D.-C. & Lu, T.-B. Interpenetrating metal–organic frameworks. Crystengcomm 18, 2596–2606 (2016).

    Article  CAS  Google Scholar 

  18. Wang, T. C. et al. Scalable synthesis and post-modification of a mesoporous metal–organic framework called NU-1000. Nat. Protoc. 11, 149–162 (2016).

    Article  CAS  Google Scholar 

  19. Deria, P. et al. Perfluoroalkane functionalization of NU-1000 via solvent-assisted ligand incorporation: synthesis and CO2 adsorption studies. J. Am. Chem. Soc. 135, 16801–16804 (2013).

    Article  CAS  Google Scholar 

  20. Feng, D. et al. Zirconium–metalloporphyrin PCN-222: mesoporous metal–organic frameworks with ultrahigh stability as biomimetic catalysts. Angew. Chem. Int. Ed. 51, 10307–10310 (2012).

    Article  CAS  Google Scholar 

  21. Qiu, L.-G. et al. Hierarchically micro- and mesoporous metal–organic frameworks with tunable porosity. Angew. Chem. Int. Ed. 47, 9487–9491 (2008).

    Article  CAS  Google Scholar 

  22. Sun, L.-B., Li, J.-R., Park, J. & Zhou, H.-C. Cooperative template-directed assembly of mesoporous metal–organic frameworks. J. Am. Chem. Soc. 134, 126–129 (2012).

    Article  CAS  Google Scholar 

  23. Kirchon, A. et al. Modulation versus templating: fine-tuning of hierarchally porous PCN-250 using fatty acids to engineer guest adsorption. Angew. Chem. Int. Ed. 58, 12425–12430 (2019).

    Article  CAS  Google Scholar 

  24. Bondorf, L. et al. Isotope-selective pore opening in a flexible metal–organic framework. Sci. Adv. 8, eabn7035 (2022).

    Article  CAS  Google Scholar 

  25. Wang, J. et al. Optimizing pore space for flexible-robust metal–organic framework to boost trace acetylene removal. J. Am. Chem. Soc. 142, 9744–9751 (2020).

    Article  CAS  Google Scholar 

  26. Chanut, N. et al. Tailoring the separation properties of flexible metal–organic frameworks using mechanical pressure. Nat. Commun. 11, 1216 (2020).

    Article  CAS  Google Scholar 

  27. Yue, Y., Fulvio, P. F. & Dai, S. Hierarchical metal–organic framework hybrids: perturbation-assisted nanofusion synthesis. Acc. Chem. Res. 48, 3044–3052 (2015).

    Article  CAS  Google Scholar 

  28. Peng, L. et al. Preserving porosity of mesoporous metal–organic frameworks through the introduction of polymer guests. J. Am. Chem. Soc. 141, 12397–12405 (2019).

    Article  CAS  Google Scholar 

  29. Cai, G., Yan, P., Zhang, L., Zhou, H.-C. & Jiang, H.-L. Metal–organic framework-based hierarchically porous materials: synthesis and applications. Chem. Rev. 121, 12278–12326 (2021).

    Article  CAS  Google Scholar 

  30. Feng, L., Wang, K.-Y., Lv, X.-L., Yan, T.-H. & Zhou, H.-C. Hierarchically porous metal–organic frameworks: synthetic strategies and applications. Natl Sci. Rev. 7, 1743–1758 (2020).

    Article  CAS  Google Scholar 

  31. Peng, S. et al. Metal–organic frameworks for precise inclusion of single-stranded DNA and transfection in immune cells. Nat. Commun. 9, 1293 (2018).

    Article  Google Scholar 

  32. Chen, Y., Li, P., Modica, J. A., Drout, R. J. & Farha, O. K. Acid-resistant mesoporous metal–organic framework toward oral insulin delivery: protein encapsulation, protection, and release. J. Am. Chem. Soc. 140, 5678–5681 (2018).

    Article  CAS  Google Scholar 

  33. Zheng, H. et al. One-pot synthesis of metal–organic frameworks with encapsulated target molecules and their applications for controlled drug delivery. J. Am. Chem. Soc. 138, 962–968 (2016).

    Article  CAS  Google Scholar 

  34. Feng, D. et al. Stable metal–organic frameworks containing single-molecule traps for enzyme encapsulation. Nat. Commun. 6, 5979 (2015).

    Article  Google Scholar 

  35. Jiang, Z. et al. Filling metal–organic framework mesopores with TiO2 for CO2 photoreduction. Nature 586, 549–554 (2020).

    Article  CAS  Google Scholar 

  36. Zhao, D. et al. Triblock copolymer syntheses of mesoporous silica with periodic 50 to 300 Angstrom pores. Science 279, 548–552 (1998).

    Article  CAS  Google Scholar 

  37. Kresge, C. T., Leonowicz, M. E., Roth, W. J., Vartuli, J. C. & Beck, J. S. Ordered mesoporous molecular sieves synthesized by a liquid-crystal template mechanism. Nature 359, 710–712 (1992).

    Article  CAS  Google Scholar 

  38. Beck, J. S. et al. A new family of mesoporous molecular sieves prepared with liquid crystal templates. J. Am. Chem. Soc. 114, 10834–10843 (1992).

    Article  CAS  Google Scholar 

  39. Grün, M., Lauer, I. & Unger, K. K. The synthesis of micrometer- and submicrometer-size spheres of ordered mesoporous oxide MCM-41. Adv. Mater. 9, 254–257 (1997).

    Article  Google Scholar 

  40. Tang, F., Li, L. & Chen, D. Mesoporous silica nanoparticles: synthesis, biocompatibility and drug delivery. Adv. Mater. 24, 1504–1534 (2012).

    Article  CAS  Google Scholar 

  41. Evans, J., Zaki, A. B., El-Sheikh, M. Y. & El-Safty, S. A. Incorporation of transition-metal complexes in functionalized mesoporous silica and their activity toward the oxidation of aromatic amines. J. Phys. Chem. B 104, 10271–10281 (2000).

    Article  CAS  Google Scholar 

  42. Kowalewski, T., Tsarevsky, N. V. & Matyjaszewski, K. Nanostructured carbon arrays from block copolymers of polyacrylonitrile. J. Am. Chem. Soc. 124, 10632–10633 (2002).

    Article  CAS  Google Scholar 

  43. Yasuda, H., Tamai, H., Ikeuchi, M. & Kojima, S. Extremely large mesoporous carbon fibers synthesized by the addition of rare earth metal complexes and their unique adsorption behaviors. Adv. Mater. 9, 55–58 (1997).

    Article  Google Scholar 

  44. Tamon, H., Ishizaka, H., Araki, T. & Okazaki, M. Control of mesoporous structure of organic and carbon aerogels. Carbon 36, 1257–1262 (1998).

    Article  CAS  Google Scholar 

  45. Ryoo, R., Joo, S. H. & Jun, S. Synthesis of highly ordered carbon molecular sieves via template-mediated structural transformation. J. Phys. Chem. B 103, 7743–7746 (1999).

    Article  CAS  Google Scholar 

  46. Joo, S. H. et al. Ordered nanoporous arrays of carbon supporting high dispersions of platinum nanoparticles. Nature 412, 169–172 (2001).

    Article  CAS  Google Scholar 

  47. Kim, K. et al. Lanthanum-catalysed synthesis of microporous 3D graphene-like carbons in a zeolite template. Nature 535, 131–135 (2016).

    Article  CAS  Google Scholar 

  48. Liang, C., Li, Z. & Dai, S. Mesoporous carbon materials: synthesis and modification. Angew. Chem. Int. Ed. 47, 3696–3717 (2008).

    Article  CAS  Google Scholar 

  49. Eftekhari, A. & Fan, Z. Ordered mesoporous carbon and its applications for electrochemical energy storage and conversion. Mat. Chem. Front. 1, 1001–1027 (2017).

    Article  CAS  Google Scholar 

  50. Yuan, D., Zhao, D., Timmons, D. J. & Zhou, H.-C. A stepwise transition from microporosity to mesoporosity in metal–organic frameworks by thermal treatment. Chem. Sci. 2, 103–106 (2011).

    Article  CAS  Google Scholar 

  51. Jeong, G.-Y. et al. Metal–organic framework patterns and membranes with heterogeneous pores for flow-assisted switchable separations. Nat. Commun. 9, 3968 (2018).

    Article  Google Scholar 

  52. Guillerm, V., Xu, H., Albalad, J., Imaz, I. & Maspoch, D. Postsynthetic selective ligand cleavage by solid–gas phase ozonolysis fuses micropores into mesopores in metal–organic frameworks. J. Am. Chem. Soc. 140, 15022–15030 (2018).

    Article  CAS  Google Scholar 

  53. Qi, S.-C. et al. Generation of hierarchical porosity in metal–organic frameworks by the modulation of cation valence. Angew. Chem. Int. Ed. 58, 10104–10109 (2019).

    Article  CAS  Google Scholar 

  54. Yuan, S. et al. Construction of hierarchically porous metal–organic frameworks through linker labilization. Nat. Commun. 8, 15356 (2017).

    Article  CAS  Google Scholar 

  55. Feng, L. et al. Creating hierarchical pores by controlled linker thermolysis in multivariate metal–organic frameworks. J. Am. Chem. Soc. 140, 2363–2372 (2018).

    Article  CAS  Google Scholar 

  56. Wang, K.-Y. et al. Rapid generation of hierarchically porous metal–organic frameworks through laser photolysis. Angew. Chem. Int. Ed. 59, 11349–11354 (2020).

    Article  CAS  Google Scholar 

  57. Feng, D. et al. Kinetically tuned dimensional augmentation as a versatile synthetic route towards robust metal–organic frameworks. Nat. Commun. 5, 5723 (2014).

    Article  CAS  Google Scholar 

  58. Yuan, S. et al. PCN-250 under pressure: sequential phase transformation and the implications for MOF densification. Joule 1, 806–815 (2017).

    Article  CAS  Google Scholar 

  59. Fang, Y. et al. Incorporating heavy alkanes in metal-organic frameworks for optimizing adsorbed natural gas capacity. Chemistry 24, 16977–16982 (2018).

    Article  CAS  Google Scholar 

  60. Cavka, J. H. et al. A new zirconium inorganic building brick forming metal organic frameworks with exceptional stability. J. Am. Chem. Soc. 130, 13850–13851 (2008).

    Article  Google Scholar 

  61. Liu, L. et al. Imaging defects and their evolution in a metal–organic framework at sub-unit-cell resolution. Nat. Chem. 11, 622–628 (2019).

    Article  CAS  Google Scholar 

  62. Yuan, S. et al. Stable metal–organic frameworks: design, synthesis, and applications. Adv. Mater. 30, e1704303 (2018).

    Article  Google Scholar 

  63. Shearer, G. C. et al. Tuned to perfection: ironing out the defects in metal–organic framework UiO-66. Chem. Mater. 26, 4068–4071 (2014).

    Article  CAS  Google Scholar 

  64. Yuan, S. et al. Stable metal–organic frameworks: design, synthesis, and applications. Adv. Mater. 30, 1704303 (2018).

    Article  Google Scholar 

  65. Devic, T. & Serre, C. High valence 3p and transition metal based MOFs. Chem. Soc. Rev. 43, 6097–6115 (2014).

    Article  CAS  Google Scholar 

  66. Wang, K. et al. Pyrazolate-based porphyrinic metal–organic framework with extraordinary base-resistance. J. Am. Chem. Soc. 138, 914–919 (2016).

    Article  CAS  Google Scholar 

  67. Liu, T.-F. et al. Topology-guided design and syntheses of highly stable mesoporous porphyrinic zirconium metal–organic frameworks with high surface area. J. Am. Chem. Soc. 137, 413–419 (2015).

    Article  CAS  Google Scholar 

  68. Wang, Y., Liu, Q., Zhang, Q., Peng, B. & Deng, H. Molecular vise approach to create metal-binding sites in MOFs and detection of biomarkers. Angew. Chem. Int. Ed. 57, 7120–7125 (2018).

    Article  CAS  Google Scholar 

  69. Yan, W. et al. Molecular vises for precisely positioning ligands near catalytic metal centers in metal–organic frameworks. J. Am. Chem. Soc. 142, 16182–16187 (2020).

    Article  CAS  Google Scholar 

  70. Zorainy, M. Y., Gar Alalm, M., Kaliaguine, S. & Boffito, D. C. Revisiting the MIL-101 metal–organic framework: design, synthesis, modifications, advances, and recent applications. J. Mater. Chem. A 9, 22159–22217 (2021).

    Article  CAS  Google Scholar 

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Acknowledgements

This work was funded by the Robert A. Welch Foundation through a Welch Endowed Chair to H.-C. Z. (A-0030) and Qatar National Research Fund under Award Number NPRP9-377-1-080. Figures 3, 4 and 6 were created with BioRender.com. The authors also appreciate the helpful discussion with G. S. Day at Framergy, Inc. and Z. Han and W. Shi at Nankai University and support from the Foresight Institute.

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Authors and Affiliations

  1. Department of Chemistry, Texas A&M University, College Station, TX, USA

    Kun-Yu Wang, Zhentao Yang, Jiaqi Zhang, Sayan Banerjee, Elizabeth A. Joseph, Yu-Chuan Hsu, Shuai Yuan, Liang Feng & Hong-Cai Zhou

  2. State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, China

    Shuai Yuan

  3. Department of Materials Science and Engineering, Texas A&M University, College Station, TX, USA

    Hong-Cai Zhou

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Contributions

K.-Y.W. organized and revised the manuscript and drew all the scientific figures. S.Y. and L.F. designed the experiments and edited the manuscript. H.-C.Z. oversaw the whole project. Z.Y. performed the linker hydrolysis experiments. J.Z. and Y.-C.H. performed the linker thermolysis experiments. S.B. and E.A.J. conducted the Soxhlet washing experiments. All authors contributed to writing the manuscript.

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Correspondence to Shuai Yuan, Liang Feng or Hong-Cai Zhou.

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Related Links

Key references using this protocol

Yuan, S. et al. Nat. Commun. 8, 15356 (2017): https://www.nature.com/articles/ncomms15356

Feng, L. et al. J. Am. Chem. Soc. 140, 2363–2372 (2018): https://pubs.acs.org/doi/10.1021/jacs.7b12916

Fang, Y. et al. Chem. Eur. J. 24, 16977–16982 (2018): https://chemistry-europe.onlinelibrary.wiley.com/doi/10.1002/chem.201804012

Extended data

Extended Data Fig. 1 The equipment setup to synthesize the H4ABTC ligand.

a, Initial setup for the synthesis. b, The appearance of the yellow precipitate after 12 h.

Extended Data Fig. 2 Color change of PCN-250 before and after activation.

a, The brown color of PCN-250 before activation. b, The black color of PCN-250 after 12 h activation at 240 °C.

Extended Data Fig. 3 Equipment setup for the Soxhlet washing of PCN-250.

a, Soxhlet extraction setup using a 500 ml round-bottom flask and a magnetic stir bar. b, The Soxhlet extractor with the PCN-250 and a water condenser.

Extended Data Fig. 4 Color of the mixed-linker UiO-66 before and after thermolysis.

a, The pale-yellow UiO-66-NH2-5% powder. b, The brown UiO-66-NH2-5% powder after heating at 350 °C. c, The pale-yellow UiO-66-NH2-28% powder. d, The dark-brown UiO-66-NH2-28% powder after heating at 350 °C.

Supplementary information

Supplementary Information

Supplementary Figs. 1–16, and Supplementary Table 1.

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Wang, KY., Yang, Z., Zhang, J. et al. Creating hierarchical pores in metal–organic frameworks via postsynthetic reactions. Nat Protoc 18, 604–625 (2023). https://doi.org/10.1038/s41596-022-00759-7

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