▎ 摘　　要

Catalytic conversion of carbon dioxide (CO2) into various highly value-added chemicals is an important challenge for the effective suppression of CO2 emission and practical utilization of CO2. The search for a catalyst for the CO2 conversion under mild conditions is a long-term target. Herein, we reported the as-received graphene oxides (GOs) alone as the efficient and green heterogeneous catalysts for the cycloaddition between epoxides and CO2 at 1.0 atm. As received GOs enabled the styrene oxide conversion of 97.8% with a 97.4% chemoselectivity to phenylethylene carbonate after 12 h of reaction. Kinetic and X-ray photoelectron spectroscopy analyses revealed that as-received GOs delivered a strong surface-depended catalytic performance, where the GO catalysts with the highest amount of the oxygen-containing groups exhibited the highest reaction rate. Control experiments indicated that the activation of CO2 realized by DMF was independent of the CO2 pressures. The activation of epoxide was achieved by the oxygen-containing groups in the GO catalysts as the surface active sites. The overall catalytic efficiency strongly depended on the surface properties of various GO catalysts for the cycloaddition reaction. Such unique carbon catalysts provide a cost-effective approach for CO2 conversion under mild conditions.