Hledat publikace

Zn-Al hydrotalcity s konstantním poměrem Zn/Al 2:1 byly připraveny koprecipitací za odlišných podmínek, jako je pH, koncentrace iontů, teplota koprecipitace, intenzita míchání atd. Všechny připravené materiály byly charakterizovány pomocí rentgenové difrakce, termogravimetrie a stanovení specifického povrchu. Materiály byly dále testovány v aldolové kondenzaci furfuralu.

The Zn-Al hydrotalcites (materials with layered structure) with constant molar ratio of Zn/Al 2:1, were synthesized by co-precipitation method under different reaction conditions such as pH, concentration of ions, temperature throughout co-precipitation, intensity of stirring, etc. The mixed oxides were formed from hydrotalcites by calcination at 450 °C. All synthesized materials were characterized by X-ray diffraction, thermogravimetric analysis and specific surface area. The influence of the synthesis conditions on the crystallite size and specific surface area were studied. The formed of hydrotalcites as well as mixed oxides was confirmed X-ray diffraction. The chosen mixed oxides were rehydrated, which caused restoration of the layered structure. The mixed oxides and rehydrated mixed oxides were tested in the aldol condensation of furfural. It was found that the rehydration decreases the conversion of furfural for all rehydrated mixed oxides.