Reconstructed Mg/Al hydrotalcite as a solid base catalyst for synthesis of jasminaldehyde

Reconstructed hydrotalcites (Mg/Al molar ratio = 3.5) of varied reconstruction time were synthesized and used as catalysts for solvent free condensation of 1-heptanal with benzaldehyde. Maximum conversion of 1-heptanal with higher selectivity to jasminaldehyde was obtained using reconstructed hydrotalcites of 8–12 h reconstruction time. Catalytic activity of reconstruction hydrotalcite was compared with as-synthesized and activated hydrotalcite of Mg/Al molar ratio 3.5 and significantly higher conversion of 1-heptanal was observed in case of reconstructed hydrotalcite of 8 h reconstruction time as a catalyst. Similar to the conversion, higher selectivity to jasminaldehyde was also obtained using reconstructed hydrotalcite. Effect of reconstruction time on conversion and selectivity to jasminaldehyde was studied by varying the reconstruction time of hydrotalcite from 0.5 to 72 h. Kinetic experiments were carried out to study the effect of stirring speed, benzaldehyde to 1-heptanal molar ratio, amount of catalyst and reaction temperature on the rate of reaction using reconstructed hydrotalcite as a catalyst.

.Figure optionsDownload high-quality image (91 K)Download as PowerPoint slideResearch highlights▶ Maximum conversion of 1-heptanal with higher selectivity to jasminaldehyde was obtained using reconstructed hydrotalcites of 8–12 h reconstruction time. ▶ Reconstructed hydrotalcite of 8 h reconstruction time showed 96% conversion of 1-heptanal within 120 min, however, 51 and 60% conversion were observed using as-synthesized and calcined hydrotalcite, respectively. ▶ Effect of stirring speed, benzaldehyde to 1-heptanal molar ratio, amount of catalyst and reaction temperature on rate of reaction was studied in detail.