Hledat publikace

Several types of zinc modified Mg–Al layered double hydroxides were prepared. Zinc was incorporated into catalyst structure using different methods—coprecipitation, kneading or impregnation. Characterization of all solid catalysts was performed using different techniques. Acido–basic properties of prepared materials were investigated using ammonia (or carbon dioxide) temperature programmed desorption. The activity of the prepared samples was compared with pure Mg–Al oxide with Mg:Al ratio 3:1 in aldol condensation of benzaldehyde and heptanal. The influence of temperature (80–120 °C) on the reaction course was monitored. Heptanal conversion and selectivity to two main products, i.e. 2-pentylcinnamylaldehyde (jasmine aldehyde) and 2 pentylnon-2-enal, were evaluated. Zinc modified catalysts exhibited under the same conditions 15–20% higher yields of the desired jasmine aldehyde.