Influence of the acid-base properties of solid catalysts derived from hydrotalcite-like compounds on the condensation of formaldehyde and acetaldehyde

摘要

The vapor-phase aldol condensation of formaldehyde with acetaldehyde was studied using various oxide mixtures obtained in situ from hydrotalcite-like materials as catalysts. All samples exhibited catalytic activity, but the selectivity to both the aldol condenstaion and the acrolein formation is governed by the balance of acidic and basic proerties. The oxides containing Mg and Al or Co and Al showed a high selectivity to aldol condenstaion (90% at 300 deg C) as well as to cross-condensation (80% at 300 deg C). The effects of both the reaction variables (temperature, mole ratio of reagents) and the catalyst variables (nature of cations, nature of anions) were studied.