Morphology Dependence of Catalytic Properties of CeO2 Nanocatalysts for One-Step CO2 Conversion to Diethyl Carbonate

The conversion of CO2 into value-added chemicals exemplifies an innovative and eco-friendly approach to addressing carbon emissions. In this study, shape-specific CeO2 nanocrystals (nanorods, nanocubes, and nanoparticles) were successfully synthesized and employed as catalysts to study the structure-dependent behavior and reaction mechanism for one-step CO2 conversion to diethyl carbonate (DEC). Among the three catalysts, CeO2 nanorods (Ce-NR) exhibited the best catalytic activity in the synthesis of DEC from CO2 compared with CeO2 nanocubes (Ce-NC) and nanoparticles (Ce-NP), which achieved the DEC production of 1.32 mmolDEC/gcat at 423 K and 5 MPa for 4 h. Comprehensive characterization further confirmed the enhanced activity of Ce-NR originated from the morphology effect, particularly the promotion of oxygen vacancies and Ce3+ species, which promoted reaction activity. Furthermore, the Ce-NR catalyst almost retained 1.32 mmolDEC/gcat DEC production of its initial activity after four cycles, underscoring its exceptional stability and promising industrial scalability. These findings provide fundamental insights to guide the rational design of efficient catalysts for CO2 activation and other critical transformations.