An Advanced Approach for MgZnAl-LDH Catalysts Synthesis Used in Claisen-Schmidt Condensation

Using organic-base tetramethylammonium hydroxide (TMAH) is a viable, cheap, and fast option for the synthesis of MgZnAl-LDH-type materials by both co-precipitation mechano-chemical methods. TMAH presents several advantages, such as smaller quantity water required in washing step compared to use inorganic alkalis, prevention LDH contamination with alkali cations, its action template molecule texture tailoring. It also has disadvantages, presence small quantities resulting layered materials. Regardless organic/inorganic bases co-precipitation/mechano-chemical methods, zincite stable phase was found all synthesized solids. The basicity catalysts followed trend: mixed oxides > reconstructed parent LDH. memory effect supported only Mg Al while Zn remained phase. catalytic activities Claisen–Schmidt condensation benzaldehyde cyclohexanone provided values higher than 90% after 2 h, total selectivity toward 2,6-dibenzylidenecyclohexanone, self-condensation yielded no more 7.29% 5 h. These behaviors depended on catalyst well planar rigidity compound.