Remarkable crystal phase effect of Cu/TiO2 catalysts on the selective hydrogenation of dimethyl oxalate

A series of Cu-based TiO2-supported catalysts were synthesized via facile ammonia evaporation for the selective hydrogenation of dimethyl oxalate (DMO) to ethylene glycol (EG). A 100% conversion of DMO, 99% selectivity for EG, and super stability were achieved over the 20% Cu/P25 TiO2 catalyst. The effect of the crystal phase of the titania support and the interaction between Cu and P25 were investigated. The active copper species located at the interface between the anatase and rutile phases play important roles in the selective hydrogenation. The excellent catalytic performance was mainly attributed to better copper dispersion and an appropriate ratio of Cu0/Cu+, which stems from the intimate interaction between Cu and the P25 support.