Effect of Co, Ti substitutions in Mg, Al-layered double hydroxides on the physico-chemical properties and catalytic activity in oxidative transformations

Considering the outstanding characteristics of layered double hydroxides (LDH), four Co and Ti-based magnetic LDH (Fe3O4-Co,Ti,Mg,Al-LDH, Fe3O4-Co,Ti,Mg-LDH, Fe3O4-Co,Ti,Al-LDH, and Fe3O4-Co,Ti-LDH) were synthesized. The effect of substituting Mg and Al atoms with Co and Ti (partially and completely) was studied on the physico-chemical properties and catalytic activity for the oxidative aromatization of 1,4-dihyropyridines (DHP) and oxidative deprotection of oximes, wherein Fe3O4-Co,Ti-LDH exhibited the best results. The synthesized catalysts were analyzed by employing different characterization techniques like Brunauer-Emmett-Teller analysis (BET), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Based on the results, the enhanced catalytic performance of Fe3O4-Co,Ti-LDH was combinedly attributed to the successful fabrication, high thermal stability and specific surface area, and more surface-active Co species. The catalyst was easily recoverable and displayed good recyclability.