화학공학소재연구정보센터
Journal of Chemical Technology and Biotechnology, Vol.93, No.1, 166-173, 2018
Aldol condensation of benzaldehyde and heptanal: a comparative study of laboratory and industrially prepared Mg-Al mixed oxides
BACKGROUNDSeveral layered double hydroxides (with Mg:Al ratio varying from 2:1 to 4:1) were prepared by a co-precipitation method at constant pH value. The activity of laboratory prepared samples was compared with that of industrially prepared layered double hydroxides with the same Mg/Al ratio in aldol condensation of benzaldehyde with heptanal. RESULTSCharacterization of all solid catalysts was performed using different techniques (ICP-MS, thermogravimetry, X-ray diffraction, DRIFT spectroscopy, nitrogen physisorption method, scanning electron microscopy). Acido-basic properties of prepared materials were investigated using ammonia (carbon dioxide, respectively) temperature programmed desorption. Heptanal conversion and selectivity to two main products, i.e. 2-pentylcinnamylaldehyde (jasmine aldehyde) and 2-pentylnon-2-enal, were monitored. All catalysts resulted in heptanal conversions higher than 95%. CONCLUSIONThe highest selectivity to jasmine aldehyde (66% at 70% heptanal conversion, 46% theoretical yield) was obtained using ESM 3:1 catalyst (100 degrees C, heptanal:benzaldehyde = 1:2 molar, solvent-free synthesis). (c) 2017 Society of Chemical Industry