The relative stability of zeolite precursor tetraalkylammonium–silicate oligomer complexes

We present a combined DFT and MP2 level molecular modeling study relevant for the early stage of the synthesis of the MFI and MEL zeolite structures. We have carried out a series of DFT molecular dynamics simulations, in order to study the relative stability of the silicate oligomer precursors taking part in the synthesis process. Based on computed silica/template interactions, we present evidence of the influence of different structure directing agents on the relative stability of large silicate oligomer complexes. They are due to a combination of differences in the internal stability of the precursor complexes and the interactions of the particular template with the silicate oligomers.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Si11 oligomers connect to form different zeolite precursors. ► Particular ring structures interconnecting Si11 units are stabilized by SDAs. ► Internal precursor stability is combined with template interaction.