Efficient ceria-manganese oxide for the direct conversion of CO2 and methanol to dimethyl carbonate

A number of Ce 1-x Mn x catalysts with different Mn contents were prepared by resol-assisted cationic coordinative co-assembly approach and used for the synthesis of dimethyl carbonate (DMC) from CO 2 and methanol. Multiple characterizations of XRD, FT-IR, TEM, BET, CO 2 -TPD, NH 3 -TPD, H 2 -TPR, XPS analyses were applied to investigate the surface properties of the Ce 1-x Mn x catalysts. It turned out that adjusting the proper concentration of Mn ions not only increased the pore volumes, but also improved the content of medium acidic and medium basic sites. When a small amount of Mn was added, the presence of Mn 2+ on the catalyst surface enhanced, facilitating the conversion of Ce 4+ to Ce 3+ , and leading to higher oxygen vacancy concentration. Consequently, the adsorption and activation of CO 2 and methanol were promoted, and the catalytic efficiency of the reaction was improved. It was found that Ce 0.95 Mn 0.05 catalyst exhibited the best catalytic activity, achieving a high DMC yield of 6.44 mmol/g (120 °C, 6.5 MPa, 4 h). Graphical Abstract