| 초록 |
The dehydration of biomass-derived lactic acid (LA) to acrylic acid (AA) is the promising green route that can replace the current propylene oxidation process, even though the selectivity control of dehydration versus decarbonylation is highly challenging. Prior studies reported that the control of catalyst acid-base properties is the key to achieve the high AA selectivity, and K-exchanged ZSM-5 especially with the potassium halide salts exhibited the selectivity to AA over ~80%. In this study, we investigate the mechanistic impact of KBr-ZSM-5 on LA dehydration through the in-situ DRIFT. In order to elucidate the effects of potassium cation and halogen anions on LA dehydration, the catalysts with alkali metals. i.e., Na-, K- and with halogens, i.e., F, Cl, Br, I, are systematically studied. Overall, we find that K and Br alter the acidity/basicity of the ZSM-5, and the formation rate of K-lactate over KBr-ZSM-5, a rate-controlling step for LA dehydration, is significantly accelerated. |
