Super-ions of sodium cations with hydrated hydroxide anions: inorganic structure-directing agents in zeolite synthesis
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Updated: Oct 11, 2025

Synthesis of Zeolites Using the ADOR Assembly-Disassembly-Organization-Reassembly Route
Published on: April 3, 2016
Karel Asselman1, Nick Pellens1, Sambhu Radhakrishnan1,2
1COK-Kat, KU Leuven, Celestijnenlaan 200F, 3001 Heverlee, Belgium. eric.breynaert@kuleuven.be.
Abstract:
In inorganic zeolite formation, a direct correspondence between liquid state species in the synthesis and the supramolecular decoration of the pores in the as-made final zeolite has never been reported. In this paper, a direct link between the sodium speciation in the synthesis mixture and the pore structure and content of the final zeolite is demonstrated in the example of hydroxysodalite. Super-ions with 4 sodium cations bound by mono- and bihydrated hydroxide are identified as structure-directing agents for the formation of this zeolite. This documentation of inorganic solution species acting as a templating agent in zeolite formation opens new horizons for zeolite synthesis by design.
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