Copper phyllosilicate-derived ultrafine copper nanoparticles with plenty of Cu0 and Cu+ for the enhanced catalytic performance of ethylene carbonate hydrogenation to methanol

The hydrogenation of CO2-derived carbonates to methanol is an alternative route for the indirect utilization of abundant C1 sources. Various Cu/SiO2 catalysts with different copper loading content prepared by using an ammonia evaporation hydrothermal method are implemented to evaluate the catalytic performance of ethylene carbonate (EC) hydrogenation to methanol and ethylene glycol (EG). The Cu loading content was identified to significantly affect the Cu nanoparticles (NPs) size and metal-support interaction. Highly dispersed Cu NPs restricted and embedded in copper phyllosilicate presented a smaller average particle size than the impregnated Cu/SiO2-IM catalyst. The xCu/SiO2 catalyst with ultrafine Cu NPs showed abundant Cu-O-Si interfaces, acidic sites, and coherent Cu-0 and Cu+ species. The 5Cu/SiO2 catalyst achieved methanol yield of 76% and EG yield of 98% at EC conversion of 99%, and no obvious deactivation was observed after long-term operation. The superior catalytic performance of the 5Cu/SiO2 catalyst is attributed to the synergetic effect between the appropriate Cu-0 surface area which provides sufficient active hydrogen, and the atomic ratio of Cu+ for the polarization and activation of carbon-oxygen bonds.

Automated summary

The hydrogenation of CO2-derived carbonates to methanol is a promising alternative for utilizing abundant C1 resources. The Cu loading content plays a crucial role in determining the size of Cu nanoparticles and the interaction with the support. The excellent catalytic performance of the Cu/SiO2 catalyst with appropriate Cu-0 surface area and Cu+ atomic ratio is attributed to the synergetic effect that provides sufficient active hydrogen and activates carbon-oxygen bonds.