화학공학소재연구정보센터
Catalysis Today, Vol.368, 173-180, 2021
Highly selective hydrogenation of diesters to ethylene glycol and ethanol on aluminum-promoted CuAl/SiO2 catalysts
A highly selective CuAl/SiO2 catalyst was prepared for the hydrogenation of dimethyl oxalate (DMO) and ethylene carbonate (EC) to ethanol and ethylene glycol (EG), respectively. Aluminum modified silica sol was used to prepare CuAl/SiO2 catalysts by a hydrothermal method. The catalytic performance of the CuAl/SiO2 catalysts with varying aluminum content was investigated at the conditions of 553 K and 2.5 MPa for DMO hydrogenation, while 453 K and 3 MPa for EC hydrogenation. The results showed that the Cu1.0Al/SiO2 catalyst exhibited the highest selectivity of ethanol (-94 %) in the DMO hydrogenation, while the Cu0.5Al/SiO2 catalyst exhibited the highest selectivity of EG (-95 %) and methanol (65 %) in the EC hydrogenation. Characterizations (e.g., TPD, TPR and XANES) indicated that the moderate aluminum modification on SiO2 in the form of ???Si?OH?Al bond could not only tune the support acidity to polarize the C??O bond of esters, but also intrinsically facilitate the dispersion of Cu active species to activate H2, which thus facilitated the selective hydrogenation reaction to EG, ethanol and methanol.