Industrial & Engineering Chemistry Research, Vol.58, No.42, 19397-19405, 2019
Nano-Au/MCeOx Catalysts for the Direct Oxidative Esterification of Methylacrolein to Methyl Esters
A series of Au-supported cerium oxide binary composite oxides doped with different metals (M = Mn, Cu, Ni, and Co) were synthesized and applied to the oxidative esterification of methylacrolein (MAL) with methanol (MeOH) to methyl methacrylate. The structural properties and states of the supports and catalysts were characterized by X-ray diffraction, Brunauer-Emmett-Teller, X-ray photoelectron spectroscopy, and inductively coupled plasma-Mass and transmission electron microscopy. The reducibility and basicity of Au/MnCeOx solid solution were tested by H-2-TPR and CO2-TPD. The effects of various operating parameters such as reaction temperature, reaction pressure, and reaction time were investigated. The highest activity with the conversion 99.9% and selectivity 90.6% for MAL can be observed using Au/MnCeOx as the catalyst because of its high reducibility and more amount of basic sites. The kinetics of gas-liquid-solid heterogeneously catalyzed oxidative esterification of MAL, O-2, and MeOH was studied. The possible reaction mechanism was also proposed.