Synthesis of nanosized MFI zeolites using Cu-containing complexes
Résumé
Nanosized MFI type zeolites were synthesized in the presence of Cu-containing complexes. The use of ethylene diamine tetraacetic acid (EDTA) as a ligand promoted the solubility and guaranteed the exclusive configuration of the copper-bearing chelate in the precursor solutions. The EDTA-assisted MFI zeolite nanocrystals (Cu-MFI-EDTA) was found to contain low amount of silanols due to formation of flexible Si-O-Cu bonds. On the contrary, when ammonia (NH 3) was used as a ligand, the copper species in the sample (Cu-MFI-NH 3) only present in the form of extra framework [Cu δ+ •••O δ-•••Cu δ+ ] n clusters. The introduction of transition metals assisted by ligands permitted the preparation of nanocrystals with variable amount of silanols and modified water affinity.
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