Effect of the different types of Sn-precursors on the properties of Sn FeMgAl-LDH samples

In this work, LDH SnFeMgAl were prepared by co-precipitation method at constant temperature and pH using different Sn precursors. Calcined and LDHs samples were then determined for their chemical, structural, acid-base, and textural properties by XRD, SEM-EDX, TGA-MS, DRIFT, N₂ physisorption, NH₃-TPD, CO₂-TPD and the Baeyer–Villiger (BV) oxidation of myrtenal. Since turbidity often occurs in tin doped LDH, the goal of this work was to find a way to use another precursor that eliminates the turbidity problem. It was found that the choice of tin precursor had a significant effect on the acid-base properties of the obtained LDH materials and thus on their catalytic activity. All prepared catalysts were active both for the BV oxidation of myrtenal itself and for the subsequent hydrolysis of the formed formate to nopinone. The best results were obtained using FeMgAl LDH in the presence of the meta-chloroperoxybenzoic acid ( m CPBA) and mixed oxide FeMgAl LDH-C in the presence of H₂O₂. In terms of nopinone yield, SnFeMgAl(Cl ⁻)-C proved to be the best catalyst, which also had the highest proportion of acid and basic active sites among all the catalysts investigated.