摘要
The direct synthesis of dimethyl carbonate (DMC) from CO 2 and methanol is a potential green alternative to the current industrial methods using toxic chemicals. Although many CeO 2 -based catalysts have been explored, the key structural factor affecting their DMC activity is still unclear. Herein, single-crystalline CeO 2 catalysts bearing distinct but well-defined Ce coordination structures were examined. We found that methanol is the key species being activated by surface Ce sites (cf. CO 2 ) to produce methyl carbonate (MC) and later DMC. The reactivity of surface methoxy species towards CO 2 varies considerably with its configuration determined by Ce coordination structures. The head-to-head terminal methoxy species converts CO 2 to MC faster than its atilt counterparts, resulting in a higher DMC activity. The bridging methoxy species is, however, too stable to react with CO 2 . The established structure-activity relation here should also guide the design of CeO 2 -based catalysts in other reactions involving methanol activation.