Investigation of ZSM-12 nanocrystals evolution derived from aluminosilicate nanobeads for sustainable production of ethyl levulinate from levulinic acid esterification with ethanol

Abstract

Abstract The evolution of hierarchical ZSM-12 nanosized crystals as a function of crystallization time has been demonstrated using amorphous aluminosilicate (AS) nanobeads as simultaneous silica and alumina sources and cyclic diquaternary ammonium as a structure-directing agent (SDA) in a one-pot hydrothermal synthesis. The physicochemical properties of the derived ZSM-12 products were characterized by means of X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS) elemental analysis, N2 physisorption, temperature-programmed desorption of ammonia (NH3-TPD), and pyridine adsorption. It is clearly demonstrated that crystallinity, textural properties, and acidity of the zeolite products are enhanced as a function of crystallization time. The structure of nanocrystalline ZSM-12 is well-developed after 120 h of crystallization and the corresponding zeolite product exhibits the promising catalytic performance for sustainable production of ethyl levulinate (EL) from levulinic acid (LA) esterification with ethanol. This contribution illustrates an alternative way to synthesize hierarchical zeolite nanocrystals with MTW framework via the use of homogeneously dispersed aluminosilicate nanobeads as the starting materials and opens up the perspectives for the sustainable application of zeolites nanosized crystals in a bulky-molecule reaction of bio-based chemical synthesis.