Low-temperature oxidation of ethanol to acetaldehyde over Mo-based catalysts

Abstract

The research and development of the green synthesis route of chemicals has become the focus of research in academia and industry. At present, the highly efficient oxidation of ethanol to acetaldehyde over non-precious metal catalysts under mild conditions is most promising, but remains a big challenge. Herein, the Mo–Sn oxide catalyst was designed to successfully realize low-temperature oxidation of ethanol to acetaldehyde, achieving an acetaldehyde selectivity of 89.3%, and ethanol conversion of 58.9% at 190 °C without CO_x formation. From the deep correlation of characterization and activity results, the weakened MoO bond and the enhanced mobility of lattice oxygen play crucial roles in the oxidation of C_α–H in the CH₃CH₂O* at lower temperatures. An optimal Mo/Sn ratio possessing multiple active centers can obviously promote the adsorption and dissociation of ethanol into CH₃CH₂O*. Furthermore, the reduced amount of medium-strong acid inhibited the formation of ethyl acetate as a byproduct.