Effects of Grain Size on the Activity of H-MFI Zeolites in Liquid-Phase Condensation of Propene with Formaldehyde

Abstract

This study investigated the activity of H-MFI catalysts modified by the top-down method in the liquid-phase Prins reaction between propene and formaldehyde. The physicochemical characterization of the catalyst demonstrated that grinding the catalyst reduces the specific surface area and affects the micropore to mesopore ratio in the samples. Reducing the grain size was found to increase the initial substrate consumption rate and reduce the diffusion limitations in the system. At the same time, grinding shifts the product composition towards a higher proportion of byproducts. An assessment of the kinetic curves enabled the researchers to propose a number of equations that accurately reflect catalyst deactivation. Both the reaction rate and deactivation rate vary directly with the zeolite dispersion, while the deactivation of the sample is more sensitive to the grain size.