There is growing evidence for the advantages of synthesizing nanosized zeolites with markedly reduced internal diffusion limitations for enhanced performances in catalysis and adsorption. Producing zeolite crystals with sizes less than 100 nm, however, is non-trivial, often requires the use of complex organics and typically results in a small product yield. Here we present an alternative, facile approach to enhance the mass-transport properties of zeolites by the epitaxial growth of fin-like protrusions on seed crystals. We validate this generalizable methodology on two common zeolites and confirm that fins are in crystallographic registry with the underlying seeds, and that secondary growth does not impede access to the micropores. Molecular modelling and time-resolved titration experiments of finned zeolites probe internal diffusion and reveal substantial improvements in mass transport, consistent with catalytic tests of a model reaction, which show that these structures behave as pseudo-nanocrystals with sizes commensurate to that of the fin. This approach could be extended to the rational synthesis of other zeolite and aluminosilicate materials.
Bibliographical noteFunding Information:
J.D.R. acknowledges support primarily from the US Department of Energy, Office of Science, Office of Basic Energy Sciences (award DE-SC0014468). J.D.R. and J.C.P. acknowledge funding from the Welch Foundation (award nos. E-1794 and E-1882, respectively). X.Z. received funding from the Swedish Research Council (award no. 2017-0432) and the Knut and Alice Wallenberg Foundation (award no. 2012.0112). P.J.D. and M.T. received funding from the Catalysis Center for Energy Innovation, a US Department of Energy—Energy Frontier Research Center under Grant DE-SC0001004. B.M.W. acknowledges financial support from a European Research Council (ERC) Advanced Grant (no. 321140) and the Netherlands Organization for Scientific Research (NWO) Gravitation Program (Netherlands Center for Multiscale Catalytic Energy Conversion, MCEC) funded by the Ministry of Education, Culture and Science of the government of the Netherlands. J.C.P. received additional funding from the National Science Foundation (award CBET-1629398). We thank P. Kumar for assistance with XRD analysis.
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