Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Visualizing pore architecture and molecular transport boundaries in catalyst bodies with fluorescent nanoprobes


The performances of porous materials are closely related to the accessibility and interconnectivity of their porous domains. Visualizing pore architecture and its role on functionality—for example, mass transport—has been a challenge so far, and traditional bulk and often non-visual pore measurements have to suffice in most cases. Here, we present an integrated, facile fluorescence microscopy approach to visualize the pore accessibility and interconnectivity of industrial-grade catalyst bodies, and link it unequivocally with their catalytic performance. Fluorescent nanoprobes of various sizes were imaged and correlated with the molecular transport of fluorescent molecules formed during a separate catalytic reaction. A direct visual relationship between the pore architecture—which depends on the pore sizes and interconnectivity of the material selected—and molecular transport was established. This approach can be applied to other porous materials, and the insight gained may prove useful in the design of more efficient heterogeneous catalysts.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Fig. 1: Visualizing accessibility and deactivation in zeolite-based catalyst bodies.
Fig. 2: Associating molecule size, type and location with accessibility.
Fig. 3: Visualizing molecular transport phenomena at different stages of a MTH reaction.
Fig. 4: Visualizing the effect of changing accessibility on catalyst performance.

Data availability

All data supporting the findings of this study are available within the Article and its Supplementary Information, and/or from the corresponding authors upon reasonable request.


  1. 1.

    Zaworotko, M. J. Materials science: designer pores made easy. Nature 451, 410–411 (2008).

    CAS  Article  Google Scholar 

  2. 2.

    Davis, M. E. Ordered porous materials for emerging applications. Nature 417, 813–821 (2002).

    CAS  Article  Google Scholar 

  3. 3.

    Kitagawa, S. Porous materials and the age of gas. Angew. Chem. Int. Ed. 54, 10686–10687 (2015).

    CAS  Article  Google Scholar 

  4. 4.

    Serrano, D. P., Escola, J. M. & Pizarro, P. Synthesis strategies in the search for hierarchical zeolites. Chem. Soc. Rev. 42, 4004–4035 (2013).

    CAS  Article  Google Scholar 

  5. 5.

    Cejka, J., Centi, G., Perez-Pariente, J., Roth, W. J. & Heyrovsk, J. Zeolite-based materials for novel catalytic applications: opportunities, perspectives and open problems. Catal. Today 179, 2–15 (2011).

    Article  Google Scholar 

  6. 6.

    Parlett, C. M. A., Wilson, K. & Lee, A. F. Hierarchical porous materials: catalytic applications. Chem. Soc. Rev. 42, 3876–3893 (2013).

    CAS  Article  Google Scholar 

  7. 7.

    Jones, A. C. et al. The correlation of pore morphology, interconnectivity and physical properties of 3D ceramic scaffolds with bone ingrowth. Biomaterials. 30, 1440–1451 (2009).

    CAS  Article  Google Scholar 

  8. 8.

    Hollister, S. J. Porous scaffold design for tissue engineering. Nat. Mater. 4, 518–524 (2005).

    CAS  Article  Google Scholar 

  9. 9.

    Pagliai, M., Vignozzi, N. & Pellegrini, S. Soil structure and the effect of management practices. Soil Tillage Res. 79, 131–143 (2004).

    Article  Google Scholar 

  10. 10.

    Nair, B. N. et al. Synthesis of gas and vapor molecular sieving silica membranes and analysis of pore size and connectivity. Langmuir 16, 4558–4562 (2000).

    CAS  Article  Google Scholar 

  11. 11.

    Moghaddam, S. et al. An inorganic–organic proton exchange membrane for fuel cells with a controlled nanoscale pore structure. Nat. Nanotech. 5, 230–236 (2010).

    CAS  Article  Google Scholar 

  12. 12.

    Milina, M., Mitchell, S., Cooke, D., Crivelli, P. & Pérez-Ramírez, J. Impact of pore connectivity on the design of long-lived zeolite catalysts. Angew. Chem. Int. Ed. 54, 1591–1594 (2015).

    CAS  Article  Google Scholar 

  13. 13.

    Du, J. et al. Hierarchically ordered macro- mesoporous TiO2–graphene composite films: improved mass transfer, reduced charge recombination, and their enhanced photocatalytic activities. ACS Nano. 5, 590–596 (2011).

    CAS  Article  Google Scholar 

  14. 14.

    Pérez-Ramírez, J., Christensen, C. H., Egeblad, K., Christensen, C. H. & Groen, J. C. Hierarchical zeolites: enhanced utilisation of microporous crystals in catalysis by advances in materials design. Chem. Soc. Rev. 37, 2530–2542 (2008).

    Article  Google Scholar 

  15. 15.

    Hartmann, M. Hierarchical zeolites: a proven strategy to combine shape selectivity with efficient mass transport. Angew. Chem. Int. Ed. 43, 5880–5882 (2004).

    CAS  Article  Google Scholar 

  16. 16.

    Christensen, C. H., Johannsen, K., Schmidt, I. & Christensen, C. H. Catalytic benzene alkylation over mesoporous zeolite single crystals: improving activity and selectivity with a new family of porous materials. J. Am. Chem. Soc. 125, 13370–13371 (2003).

    CAS  Article  Google Scholar 

  17. 17.

    Mitchell, S., Michels, N.-L., Kunze, K. & Pérez-Ramírez, J. Visualization of hierarchically structured zeolite bodies from macro to nano length scales. Nat. Chem. 4, 825–831 (2012).

    CAS  Article  Google Scholar 

  18. 18.

    Karwacki, L. et al. Morphology-dependent zeolite intergrowth structures leading to distinct internal and outer-surface molecular diffusion barriers. Nat. Mater. 8, 959–965 (2009).

    CAS  Article  Google Scholar 

  19. 19.

    Fu, D. et al. Nanoscale infrared imaging of zeolites using photoinduced force microscopy. Chem. Commun. 53, 13012–13014 (2017).

    CAS  Article  Google Scholar 

  20. 20.

    Ristanovic, Z., Kubarev, A. V., Hofkens, J., Roeffaers, M. B. J. & Weckhuysen, B. M. Single molecule nanospectroscopy visualizes proton-transfer processes within a zeolite crystal. J. Am. Chem. Soc. 138, 13586–13596 (2016).

    CAS  Article  Google Scholar 

  21. 21.

    Zhu, X. et al. Probing the influence of SSZ-13 zeolite pore hierarchy in methanol-to-olefins catalysis by using nanometer accuracy by stochastic chemical reactions fluorescence microscopy and positron emission profiling. ChemCatChem 9, 3470–3477 (2017).

    CAS  Article  Google Scholar 

  22. 22.

    Whiting, G. T. et al. Binder effects in SiO2- and Al2O3-bound zeolite ZSM-5-based extrudates as studied by microspectroscopy. ChemCatChem 7, 1312–1321 (2015).

    CAS  Article  Google Scholar 

  23. 23.

    Whiting, G. T. et al. Selective staining of Brønsted acidity in zeolite ZSM-5-based catalyst extrudates using thiophene as a probe. Phys. Chem. Chem. Phys. 16, 21531–21542 (2014).

    CAS  Article  Google Scholar 

  24. 24.

    Mitchell, S., Michels, N.-L. & Pérez-Ramírez, J. From powder to technical body: the undervalued science of catalyst scale up. Chem. Soc. Rev. 42, 6094–6112 (2013).

    CAS  Article  Google Scholar 

  25. 25.

    Corma, A., Grande, M., Fornés, V., Cartlidge, S. & Shatlock, M. P. Interaction of zeolite alumina with matrix silica in catalytic cracking catalysts. Appl. Catal. 66, 45–57 (1990).

    CAS  Article  Google Scholar 

  26. 26.

    Corma, A., Martínez, C. & Sauvanaud, L. New materials as FCC active matrix components for maximizing diesel (light cycle oil, LCO) and minimizing its aromatic content. Catal. Today 127, 3–16 (2007).

    CAS  Article  Google Scholar 

  27. 27.

    Corma, A., Grande, M., Fornés, V. & Cartlidge, S. Gas oil cracking at the zeolite–matrix interface. Appl. Catal. 66, 247–255 (1990).

    CAS  Article  Google Scholar 

  28. 28.

    Corma, A., Martı́nez-Triguero, J. & Martı́nez, C. The use of ITQ-7 as a FCC zeolitic additive. J. Catal. 197, 151–159 (2001).

    CAS  Article  Google Scholar 

  29. 29.

    Chen, N.-Y., Liu, M.-C., Yang, S.-C., Sheu, H.-S. & Chang, J.-R. Impacts of binder–zeolite interactions on the structure and surface properties of NaY–SiO2 extrudates. Ind. Eng. Chem. Res. 54, 8456–8468 (2015).

    CAS  Article  Google Scholar 

  30. 30.

    Yan T. Aromatization process and catalyst therefor. US patent 3,843,741A (1974).

  31. 31.

    Devadas, P., Kinage, A. K. & Choudhary, V. R. Effect of silica binder on acidity, catalytic activity and deactivation due to coking in propane aromatization over H-gallosilicate (MFI). Stud. Surf. Sci. Catal. 113, 425–432 (1998).

    CAS  Article  Google Scholar 

  32. 32.

    Chowdhury, A. D. et al. Electrophilic aromatic substitution over zeolites generates Wheland-type reaction intermediates. Nat. Catal. 1, 23–31 (2018).

    Article  Google Scholar 

  33. 33.

    Cychosz, K. A., Guillet-Nicolas, R., García-Martínez, J. & Thommes, M. Recent advances in the textural characterization of hierarchically structured nanoporous materials. Chem. Soc. Rev. 46, 389–414 (2017).

    CAS  Article  Google Scholar 

  34. 34.

    Weinberger, C., Vetter, S., Tiemann, M. & Wagner, T. Assessment of the density of (meso)porous materials from standard volumetric physisorption data. Micropor. Mesopor. Mater. 223, 53–57 (2016).

    CAS  Article  Google Scholar 

  35. 35.

    Xu, D., Ma, J., Song, A., Liu, Z. & Li, R. Availability and interconnectivity of pores in mesostructured ZSM-5 zeolites by the adsorption and diffusion of mesitylene. Adsorption 22, 1083–1090 (2016).

    CAS  Article  Google Scholar 

  36. 36.

    Kenvin, J. et al. Quantifying the complex pore architecture of hierarchical faujasite zeolites and the impact on diffusion. Adv. Funct. Mater. 26, 5621–5630 (2016).

    CAS  Article  Google Scholar 

  37. 37.

    da Silva, J. C. et al. Assessment of the 3D pore structure and individual components of preshaped catalyst bodies by X-ray imaging. ChemCatChem 7, 413–416 (2015).

    Article  Google Scholar 

  38. 38.

    Liu, Y., Meirer, F., Krest, C. M., Webb, S. & Weckhuysen, B. M. Relating structure and composition with accessibility of a single catalyst particle using correlative 3-dimensional micro-spectroscopy. Nat. Commun. 7, 12634 (2016).

    CAS  Article  Google Scholar 

  39. 39.

    Wei, Y., Parmentier, T. E., de Jong, K. P. & Zečević, J. Tailoring and visualizing the pore architecture of hierarchical zeolites. Chem. Soc. Rev. 44, 7234–7261 (2015).

    CAS  Article  Google Scholar 

  40. 40.

    Zou, N. et al. Cooperative communication within and between single nanocrystals. Nat. Chem. 10, 607–614 (2018).

    CAS  Article  Google Scholar 

  41. 41.

    Hendriks, F. C. et al. Single-molecule fluorescence microscopy reveals local diffusion coefficients in the pore network of an individual catalyst particle. J. Am. Chem. Soc. 139, 13632–13635 (2017).

    CAS  Article  Google Scholar 

  42. 42.

    Hendriks, F. C. et al. Integrated transmission electron and single-molecule fluorescence microscopy correlates reactivity with ultrastructure in a single catalyst particle. Angew. Chem. Int. Ed. 57, 257–261 (2018).

    CAS  Article  Google Scholar 

  43. 43.

    Conhaim, R. L. & Rodenkirch, L. A. Estimated functional diameter of alveolar septal microvessels in zone 1. Am. J. Physiol. Heart Circ. Physiol. 271, H996–H1003 (1996).

    CAS  Article  Google Scholar 

  44. 44.

    Madden, C. J., Tupone, D., Cano, G. & Morrison, S. F. α2 Adrenergic receptor-mediated inhibition of thermogenesis. J. Neurosci. 33, 2017–2028 (2013).

    CAS  Article  Google Scholar 

  45. 45.

    Soeller, C., Crossman, D., Gilbert, R. & Cannell, M. B. Analysis of ryanodine receptor clusters in rat and human cardiac myocytes. Proc. Natl Acad. Sci. USA 104, 14958–14963 (2007).

    CAS  Article  Google Scholar 

  46. 46.

    Popielarski, S. R., Pun, S. H. & Davis, M. E. A nanoparticle-based model delivery system to guide the rational design of gene delivery to the liver. 1. Synthesis and characterization. Bioconjugate Chem. 16, 1063–1070 (2005).

    CAS  Article  Google Scholar 

  47. 47.

    Fredrich, J. T., Menéndez & Wong, T.-F. Imaging the pore structure of geomaterials. Science 268, 276–279 (1996).

    Article  Google Scholar 

  48. 48.

    Mauko, A., Muck, T., Mirtic, B., Mladenovic, A. & Kreft, M. Use of confocal laser scanning microscopy (CLSM) for the characterization of porosity in marble. Mater. Charact. 60, 603–609 (2009).

    CAS  Article  Google Scholar 

  49. 49.

    Wang, W. Imaging the chemical activity of single nanoparticles with optical microscopy. Chem. Soc. Rev. 47, 2485–2509 (2018).

    CAS  Article  Google Scholar 

  50. 50.

    Sperinck, S., Raiteri, P., Marks, N. & Wright, K. Dehydroxylation of kaolinite to metakaolin—a molecular dynamics study. J. Mater. Chem. 21, 2118–2125 (2011).

    CAS  Article  Google Scholar 

  51. 51.

    Yarulina, I., Chowdhury, A. D., Meirer, F., Weckhuysen, B. M. & Gascon, J. Recent trends and fundamental insights in the methanol-to-hydrocarbons process. Nat. Catal. 1, 398–411 (2018).

    Article  Google Scholar 

  52. 52.

    Keil, F. J. Methanol-to-hydrocarbons: process technology. Micropor. Mesopor. Mater. 29, 49–66 (1999).

    CAS  Article  Google Scholar 

  53. 53.

    Buurmans, I. L. C. et al. Catalytic activity in individual cracking catalyst particles imaged throughout different life stages by selective staining. Nat. Chem. 3, 862–867 (2011).

    CAS  Article  Google Scholar 

  54. 54.

    Qian, Q. et al. Single-particle spectroscopy on large SAPO-34 crystals at work: methanol-to-olefin versus ethanol-to-olefin processes. Chem. Eur. J. 19, 11204–11215 (2013).

    CAS  Article  Google Scholar 

  55. 55.

    Palumbo, L. et al. Conversion of methanol to hydrocarbons: spectroscopic characterization of carbonaceous species formed over H-ZSM-5. J. Phys. Chem. C 112, 9710–9716 (2008).

    CAS  Article  Google Scholar 

  56. 56.

    Van Speybroeck, V. et al. Mechanistic studies on chabazite-type methanol-to-olefin catalysts: Insights from time-resolved UV/vis microspectroscopy combined with theoretical simulations. ChemCatChem 5, 173–184 (2013).

    Article  Google Scholar 

  57. 57.

    Mores, D., Kornatowski, J., Olsbye, U. & Weckhuysen, B. M. Coke formation during the methanol-to-olefin conversion: in situ microspectroscopy on individual H-ZSM-5 crystals with different Brønsted acidity. Chem. Eur. J. 17, 2874–2884 (2011).

    CAS  Article  Google Scholar 

  58. 58.

    de Winter, D. A. M., Meirer, F. & Weckhuysen, B. M. FIB–SEM tomography probes the mesoscale pore space of an individual catalytic cracking particle. ACS Catal. 6, 3158–3167 (2016).

    Article  Google Scholar 

Download references


The authors thank M. Rivera Torrente (Utrecht University, UU), I. Beurroies and M. V. Coulet (Aix-Marseille University) for Hg porosimetry data analysis, as well as R. Dalebout (UU) for Ar physisorption measurements. M. de Winter (UU) is thanked for his contribution to FIB–SEM measurements. F. Meirer (UU) and M. Vesely (UU) are also thanked for valuable discussions. This work was funded by a Netherlands Organisation for Scientific Research (NWO) Veni grant, awarded to G.T.W. (no. 722.015.003), a Marie Skłodowska-Curie grant agreement (no. 704544) (to A.D.C.) and a NWO Gravitation program (Netherlands Center for Multiscale Catalytic Energy Conversion, MCEC; to B.M.W.).

Author information




G.T.W., N.N., I.N. and A.D.C. contributed to the preparation, characterization and testing of samples. G.T.W. and B.M.W. designed and directed the project. All authors discussed the results and commented on the manuscript.

Corresponding authors

Correspondence to Gareth T. Whiting or Bert M. Weckhuysen.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Data, Supplementary Methods, Statistical Analysis

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Whiting, G.T., Nikolopoulos, N., Nikolopoulos, I. et al. Visualizing pore architecture and molecular transport boundaries in catalyst bodies with fluorescent nanoprobes. Nature Chem 11, 23–31 (2019).

Download citation

Further reading


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing