Facile Fabrication of Ultrasmall Copper Species Confined in Mesoporous Silica for Chemo-Selective and Stable Hydrogenation Ethylene Carbonate Derived from CO2

The hydrogenation of ethylene carbonate to co-produce commodity methanol and ethylene glycol has attracted growing interests due to the potential chemical utilization of CO2 in large scale. In this work, we report a novel and facile protocol for the preparation of mesoporous Cu@SiO2 catalysts and successfully applied the as-synthesized catalysts in the hydrogenation of ethylene carbonate.

The catalysts were characterized in detail by means of N-2 physisorption, N2O titration, XRD, FT-IR, H-2-TPR, TEM and XPS (XAES). This strategy is an effective method for fabricating the unique flower-like mesoporous Cu@SiO2 with sub-2.0nm ultrasmall Cu particles. The results revealed that the involvement of -cyclodextrin improved the Cu dispersion and facilitated exposing more copper active sites, which also indicated that the confined catalyst inhibiting the sintering of copper particles.

Meanwhile, the stability of the attained catalyst was superior with the modification of carbon. Importantly, among the catalysts tested in the hydrogenation of ethylene carbonate, 25Cu@SiO2--P with appropriate copper loading as well as moderate Cu+ ratio exhibited superior catalytic performance. Accordingly, the synergistic effect between the Cu+ and metallic Cu-0 species was crucial for obtaining better catalytic activity.