Structure Evolution and Restricted Deterioration of the Cu/SiO ₂ Catalyst in Persistent Diethylene Glycol Dehydrogenation

The activity and long-term stability of supported Cu metal catalysts were of great importance to many oxygenate conversions and of concern in both academia and industry. Herein, the catalytic performance of Cu/SiO2 was examined for diethylene glycol dehydrogenation to para-dioxanone, and the mechanism of catalysts’ rapid deactivation at various temperatures was clearly illustrated. It was shown that diethylene glycol (DEG) flow greatly damaged the support structure through the chelating interaction, leading to severe metal aggregation and catalyst deactivation. Accordingly, we found that the oriented modification of ceria onto Si–OH by the grafting strategy could strengthen the texture linkage of the SiO2 surface, avoiding the loss of Si–O units and stabilizing Cu dispersion. The improved electronic and structural properties of Ce/CuSi guaranteed a consecutive catalytic dehydrogenation performance at 90% DEG conversion over 260 h.