CeO2-Catalyzed esterification of CO2, a well-known greenhouse gas, with methanol has been widely recognized as a promising alternative method to produce dimethyl carbonate (DMC). Herein, we performed a comprehensive study of catalytic mechanisms underlying the formation of DMC from CO2and methanol on both stoichiometric and reduced CeO2(111) and (110) surfaces. To this end, the saddle-point searching algorithm is employed. Specifically, using the monomethyl carbonate (MMC) as the key intermediate, a three-step Langmuir-Hinshelwood (LH) mechanism, including the formation and esterification of monomethyl carbonate and removal of water molecule, is identified for the catalytic DMC formation on either the reduced or the stoichiometric CeO2(111) and (110) surfaces. For both CeO2(111) and (110) surfaces, our study indicates that the presence of oxygen vacancies can markedly lower the activation energy barrier. Different rate-limiting steps are identified, however, for the reduced CeO2(111) and (110) surfaces. Successful identification of the rate-limiting step and the associated active CO2species will provide atomic-level guidance on selection of metal-oxide-based catalysts toward direct synthesis of DMC from the green-house gas CO2and methanol.
|Original language||English (US)|
|Number of pages||7|
|Journal||Physical Chemistry Chemical Physics|
|State||Published - Aug 14 2021|
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry