Study on the synthesis of MFI and FER in the presence of n-butylamine and the property of n-butylamine in a confined region of zeolites

Abstract

ZSM-5 and ferrierite have been successfully hydrothermally crystallized in a gel system of sodium aluminosilicate using n-butylamine (n-BA) as structure directing agent. The zeolite crystals obtained were characterized by X-ray diffraction (XRD), infrared spectra (IR), Raman spectra, thermal analysis (TG/DTA), elemental analysis (EA), inductively coupled plasma emission spectrometry (ICP) and ¹³C NMR spectroscopy. The location and charge of the n-BA present within the solid materials were found to be significant, and it is possible to identity the nature of the organic species occluded in the channel system of the as-synthesized zeolites. n-BA is occluded in its protonated form together with dibutylamine in ZSM-5, while incorporated intact in its protonated form in ferrierite. Furthermore, the oxidation of n-BA restricted in zeolites by H₂O₂ has been studied. It is found that the restricted organic species in zeolites were oxidized by H₂O₂, and the oxidation products are different from the bulk reaction. The adsorption tests illustrated that the as-synthesized zeolites and their oxidized products have a high adsorption capacity for Ni(II). This work not only opens new opportunities for further research of zeolites and inorganic hybrids, but also provides a new idea for the application study of the SDAs present in molecular sieves.