Catalysis Letters, Vol.142, No.9, 1121-1127, 2012
Highly-Dispersed Copper-Based Catalysts from Cu-Zn-Al Layered Double Hydroxide Precursor for Gas-Phase Hydrogenation of Dimethyl Oxalate to Ethylene Glycol
The highly-dispersed copper-based catalysts for the gas-phase hydrogenation of dimethyl oxalate to ethylene glycol (EG) were prepared from a Cu-Zn-Al layered double hydroxide (LDH) precursor. Powder X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), N-2 adsorption-desorption, H-2 temperature programmed reduction (H-2-TPR) and H-2-N2O titration indicated that the composition, texture, and structure of resulting copper-based catalysts were profoundly affected by the calcination temperature of LDH precursor. Moreover, the as-synthesized catalyst calcined at 600 A degrees C was found to exhibit a superior catalytic hydrogenation performance with an EG yield of 94.7 % to the other catalysts calcined at 500 and 700 A degrees C, which should be mainly attributed to the presence of the highly-dispersed active metallic copper species over metal oxide matrix.
Keywords:Metallic copper;Layered double hydroxide precursor;High dispersion;Dimethyl oxalate;Hydrogenation