Fast Synthesis of Metal-incorporated NKX-2 (MeNKX-2) Using Novel Ionic Liquid via Ionothermal Approach

The incorporation of other metal and non-metal cations into thealuminophosphate (MeAlPO-n) molecular sieves has played a major role in enhancing their applications in the field of adsorption, separation, the formation of host-guest advanced materials and catalysis. These materials are usually synthesized under hydrothermal condition. Recently, the ionothermal method has been reported as a green synthesis approach for the synthesis of aluminophosphate (AlPO-n) and metalloaluminophosphate (MeAlPO-n) materials by using non-volatile ionic liquids as a solvent and a structure directing agent. In this work, ionothermal synthesis of metastable metal-incorporated aluminophosphite NKX-2 (MeNKX-2), where Me = Zr, Cr, Co and Fe) using 1-benzyl-2,3-dimethylimidazolium chloride, [bdmim]Cl new ionic liquid was reported. The ionic liquid was first prepared and characterized before use for the synthesis of molecular sieves. The synthesized MeNKX-2 series were then characterized by X-ray diffraction, Fourier transform-infrared spectroscopy, scanning electron microscopy coupled with energy dispersive X-ray spectroscopy and ultraviolet-visible spectroscopy. The analyses revealed that MeNKX-2 could be synthesized in a fast and convenient way and the crystals with unique morphology could be obtained within 20 min instead of several days under hydrothermal condition.