Constructing mesoporous CeO2 single-crystal particles in ionic liquids for enhancing the conversion of CO2 and alcohols to carbonates

Abstract

Catalysts for CO₂ value-added conversion have been extensively explored, but there is still a lack of systematic design for catalysts that achieve efficient CO₂ conversion under mild conditions. Herein, we explored a mesoporous CeO₂ single-crystal formed with the regulation of ionic liquids, which catalyzed the effective carbonylation reaction with CO₂ under mild reaction conditions. By altering the synthetic environment, a series of uniform mesoporous CeO₂ particles with atomically aligned single-crystal frameworks were constructed, which have different surface physicochemical properties and primary aggregation degree. The prepared mesoporous CeO₂ single-crystal achieved efficient activation of CO₂ and alcohols at 0.5 MPa CO₂ and 100 °C, and the CeO₂-IL-M catalyst shows optimal catalytic performance in the synthesis of ethylene carbonate with 46.22 mmol g^–1 h^–1, which was 50.6 times as high as that of the CeO₂ obtained without ionic liquids. Subsequently, the catalytic pathway and mechanism of carbonylation reaction with CO₂ on mesoporous CeO₂ single-crystal were studied via React-IR spectra and C¹⁸O₂ labeling experiments. The research provides a new strategy for controllable nanoscale assembly of mesoporous single-crystal materials and expands the application range of single-crystal materials, aiming to develop novel catalytic materials to meet industrial needs.