Layered Hydroxide Salts as Catalysts for Cyclohexanone Ketalization: Impact of Synthetic Method and Composition

ABSTRACT This work reports the systematic evaluation of the synthetic route used to prepare several layered hydroxide salts (LHS) based on nitrate salts of cobalt, copper, nickel, and zinc and their physicochemical and catalytic properties. Four synthetic methods were investigated: hydrothermal (H), ammonia diffusion (A), mechanochemical (M), and precipitation (P) and the LHS obtained were characterized by different techniques such as X‐ray diffraction (XRD), Fourier‐transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The influence of the four synthetic methods on the structure of the prepared LHS is discussed, as well as the impacts on their catalytic activity. The synthesized LHS were employed as catalysts for the ketalization of cyclohexanone with methanol and it was observed that the changes in the metal (II) and different synthetic method used to prepare the LHS lead to a substantial impact in the catalytic results, suggesting that these variables are important tools to direct the best and appropriate use of this family of layered solids.