2025 AIChE Annual Meeting

(30f) A Curated Database for Pure-Silica Zeolites

Authors

J. Ilja Siepmann, University of Minnesota-Twin Cities
Zeolites are inorganic crystalline nanoporous materials with industrial applications such as adsorption, separation, and catalysis.1 Pure-silica zeolites (PSZ), a subset of zeolites, are hydrophobic and are crucial for moisture-sensitive applications, but a substantial fraction of known zeolite frameworks have not yet been synthesized in their pure-silica form. The International Zeolite Association (IZA) database3 is the prevalent database for experimentally synthesized zeolite structure. The IZA database also contains hypothetical PSZ structures that are obtained using geometric restraints.

In this work, we have developed an automated workflow that evaluates and optimizes the PSZ framework structures in the IZA database. This workflow involves (i) a connectivity check to remove structures with fractional atoms and/or terminal silanol groups, (ii) a hydrophilicity check involving Gibbs ensemble Monte Carlo simulations to check for hydrophilic sites/pockets, (iii) density functional theory (DFT) calculations to optimize the atomic position and cell parameters and analyze energetic stability, and (iv) a symmetrization of the DFT-optimized structure and calculation of various geometric, energetic, and adsorption properties. The DFT-optimized structures yield a wider differentiation of Si–O bond lengths and O–Si–O bending angles than those obtained using geometric restraints. Energetics points to a subset of structures potentially synthesizable in their PSZ form. The curated database serves as a valuable resource for data-driven materials design.

References

  1. Zheng, A., Xu, F., Liu, B., Kordala, N., & Wyszkowski, M. (2024). Zeolite Properties, Methods of Synthesis, and Selected Applications. , 29, 1069.
  2. Baerlocher, C.; McCusker, L. Database of Zeolite Structures.
  3. Smeets, S., McCusker, L. B., Baerlocher, C., Mugnaioli, E., & Kolb, U. (2013). Appl. Crystallogr., 46, 1017–1023.