Catalytic dehydration of methyl lactate to methyl acrylate over potassium-exchanged organic-free ZSM-5 zeolites

Abstract

In this study, we investigated the catalytic properties of the potassium-exchanged form of commercial and organic-free synthesized ZSM-5 zeolites with similar Si/Al and K/Al ratios (10–25 and 0.80–1.00, respectively) for the dehydration of biomass-derived methyl lactate to methyl acrylate under different reaction temperatures (340 and 360 °C) and reactant concentrations (35 and 64 wt%). It was found that organic-free synthesized K-ZSM-5 shows a higher methyl acrylate yield than commercially available K-ZSM-5, regardless of the reaction conditions studied. The comprehensive catalytic and characteristic findings from our study demonstrate that K⁺ ions, acting as active sites, are uniformly distributed within the 10-ring straight and sinusoidal channels of organic-free synthesized K-ZSM-5. This unique configuration imparts greater catalytic activity relative to commercially available K-ZSM-5 for the dehydration of methyl lactate to methyl acrylate with superior reusability even with identical zeolite topology and similar compositions.