Morphology-dependent zeolite intergrowth structures leading to distinct internal and outer-surface molecular diffusion barriers
Source abstract
Abstract
Zeolites play a crucial part in acid-base heterogeneous catalysis. Fundamental insight into their internal architecture is of great importance for understanding their structure-function relationships. Here, we report on a new approach correlating confocal fluorescence microscopy with focused ion beam-electron backscatter diffraction, transmission electron microscopy lamelling and diffraction, atomic force microscopy and X-ray photoelectron spectroscopy to study a wide range of coffin-shaped MFI-type zeolite crystals differing in their morphology and chemical composition. This powerful combination demonstrates a unified view on the morphology-dependent MFI-type intergrowth structures and provides evidence for the presence and nature of internal and outer-surface barriers for molecular diffusion. It has been found that internal-surface barriers originate not only from a 90 degrees mismatch in structure and pore alignment but also from small angle differences of 0.5 degrees-2 degrees for particular crystal morphologies. Furthermore, outer-surface barriers seem to be composed of a silicalite outer crust with a thickness varying from 10 to 200 nm.
Source: europepmc · Quality: candidate unverified · Source record ↗
Research context
OpenAlex topics: Zeolite Catalysis and Synthesis · Mesoporous Materials and Catalysis · Clay minerals and soil interactions
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (28)
Show source-provided references
1. Corma, A. Inorganic solid acids and their use in acid-catalyzed hydrocarbon reactions. Chem. Rev. 95, 559–614 (1995).10.1021/cr00035a006 ↗
2. Corma, A. & Martinez, A. Zeolites and zeotypes as catalysts. Adv. Mater. 7, 137–144 (1995).10.1002/adma.19950070206 ↗
3. den Hollander, M. A., Wissink, M., Makkee, M. & Moulijn, J. A. Gasoline conversion: Reactivity towards cracking with equilibrated FCC and ZSM-5 catalysts. Appl. Catal. A 223, 85–102 (2002).10.1016/S0926-860X(01)00745-1 ↗
4. Quann, R. J., Green, L. A., Tabak, S. A. & Krambeck, F. J. Chemistry of olefin oligomerization over ZSM-5 catalyst. Ind. Eng. Chem. Res. 27, 565–570 (1988).10.1021/ie00076a006 ↗
5. Wu, X. C. & Anthony, R. G. Alkylation of benzene with formaldehyde over ZSM-5. J. Catal. 184, 294–297 (1999).10.1006/jcat.1999.2426 ↗
6. Price, G. D., Pluth, J. J., Smith, J. V., Bennett, J. M. & Patton, R. L. Crystal structure of tetrapropylammonium fluoride containing precursor to fluoride silicalite. J. Am. Chem. Soc. 104, 5971–5977 (1982).10.1021/ja00386a023 ↗
7. Weidenthaler, C., Fischer, R. X., Shannon, R. D. & Medenbach, O. Optical investigations of intergrowth effects in the zeolite catalysts ZSM-5 and ZSM-8. J. Phys. Chem. 98, 12687–12694 (1994).10.1021/j100099a036 ↗
8. Kocirik, M. et al. Investigation of sorption and transport of sorbate molecules in crystals of MFI structure type by iodine indicator technique. Micropor. Mesopor. Mater. 23, 295–308 (1998).10.1016/S1387-1811(98)00126-7 ↗
9. Agger, J. R. et al. Silicalite crystal growth investigated by atomic force microscopy. J. Am. Chem. Soc. 125, 830–839 (2003).10.1021/ja020899f ↗
10. Stavitski, E., Drury, M. R., de Winter, D. A. M., Kox, M. H. F. & Weckhuysen, B. M. Intergrowth structure of zeolite crystals and pore orientation of individual subunits revealed by electron backscatter diffraction/focused ion beam experiments. Angew. Chem. Int. Ed. 47, 5637–5640 (2008).10.1002/anie.200801433 ↗
11. Kox, M. H. F., Stavitski, E. & Weckhuysen, B. M. Nonuniform catalytic behavior of zeolite crystals as revealed by in situ optical microspectroscopy. Angew. Chem. Int. Ed. 46, 3652–3655 (2007).10.1002/anie.200700246 ↗
12. Stavitski, E., Kox, M. H. F. & Weckhuysen, B. M. Revealing shape selectivity and catalytic activity trends within the pores of H-ZSM-5 crystals by time- and space-resolved optical and fluorescence microspectroscopy. Chem. Eur. J. 13, 7057–7065 (2007).10.1002/chem.200700568 ↗
13. Caro, J. et al. Selective sorption uptake kinetics of n-hexane on ZSM-5—a new method for measuring anisotropic diffusivities. J. Phys. Chem. 97, 13685–13690 (1993).10.1021/j100153a043 ↗
14. Hay, D. G., Jaeger, H. & Wilshier, K. G. Systematic intergrowth in crystals of ZSM-5 zeolite. Zeolites 10, 571–576 (1990).10.1016/S0144-2449(05)80314-8 ↗
15. Roeffaers, M. B. J. et al. Morphology of large ZSM-5 crystals unravelled by fluorescence microscopy. J. Am. Chem. Soc. 130, 5763–5772 (2008).10.1021/ja7113147 ↗
16. Roeffaers, M. B. J. et al. Relating pore structure to activity at the subcrystal level for ZSM-5: An electron backscattering diffraction and fluorescence microscopy study. J. Am. Chem. Soc. 130, 13516–13517 (2008).10.1021/ja8048767 ↗
17. Karwacki, L., Stavitski, E., Kox, M. H. F., Kornatowski, J. & Weckhuysen, B. M. Intergrowth structure of zeolitic crystals as determined by optical and fluorescence microscopy of the template removal process. Angew. Chem. Int. Ed. 46, 7228–7231 (2007).10.1002/anie.200702012 ↗
18. Chmelik, C. et al. Effect of surface modification on uptake rates of isobutane in MFI crystals: An infrared microscopy study. Chem. Mater. 19, 6012–6019 (2007).10.1021/cm071632o ↗
19. Wloch, J. & Kornatowski, J. Sorption rate and thermal barriers in AgAs–zeolite system: Investigation of n-hexane sorption in MFI-type zeolite. Langmuir 20, 1180–1183 (2004).10.1021/la020979x ↗
20. Tzoulaki, D., Heinke, L., Schmidt, W., Wilczok, U. & Karger, J. Exploring crystal morphology of nanoporous hosts from time-dependent guest profiles. Angew. Chem. Int. Ed. 47, 3954–3957 (2008).10.1002/anie.200705597 ↗
21. Weckhuysen, B. M. Chemical imaging of spatial heterogeneities in catalytic solids at different length and time scales. Angew. Chem. Int. Ed. 48, 4910–4943 (2009).10.1002/anie.200900339 ↗
22. Dorset, D. L. Electron crystallography of zeolites. 1. Projected crystal structures of ZSM-5 and ZSM-11. Z. Kristallogr. 218, 458–465 (2003).10.1524/zkri.218.7.458.20714 ↗
23. Dorset, D. L., Gilmore, C. J., Jorda, J. L. & Nicolopoulos, S. Direct electron crystallographic determination of zeolite zonal structures. Ultramicroscopy 107, 462–473 (2007).10.1016/j.ultramic.2006.05.013 ↗
24. Seebacher, C. et al. Visualization of mesostructures and organic guest inclusion in molecular sieves with confocal microscopy. Adv. Mater. 13, 1374–1377 (2001).10.1002/1521-4095(200109)13:18<1374::AID-ADMA1374>3.0.CO;2-A ↗
25. Wloch, J. Effect of surface etching of ZSM-5 zeolite crystals on the rate of n-hexane sorption. Micropor. Mesopor. Mater. 62, 81–86 (2003).10.1016/S1387-1811(03)00395-0 ↗
26. Kortunov, P. et al. Influence of defects on the external crystal surface on molecular uptake into MFI-type zeolites. Chem. Mater. 16, 3552–3558 (2004).10.1021/cm0401645 ↗
27. Derouane, E. G., Detremmerie, S., Gabelica, Z. & Blom, N. Synthesis and characterization of ZSM-5 type zeolites I. Physico-chemical properties of precursors and intermediates. Appl. Catal. 1, 201–224 (1981).10.1016/0166-9834(81)80007-3 ↗
28. von Ballmoos, R. & Meier, W. M. Zoned aluminium distribution in synthetic zeolite ZSM-5. Nature 289, 782–783 (1981).10.1038/289782a0 ↗