Ordered Mesoporous CeO2-supported Ag as an Effective Catalyst for Carboxylative Coupling Reaction Using CO2

Ag/Mesoporous CeO2 (Ag/M-CeO2) catalysts were synthesized through the gas bubbling-assisted membrane reduction (GBMR) method and characterized by XRD, ICP-OES, N-2 adsorption-desorption, XPS, Raman spectroscopy, TEM, HRTEM, HAADF-STEM and CO2-TPD. Ag/M-CeO2 catalysts contain uniform mesoporous structure, large surface area and oxygen vacancies, which promote the dispersion of Ag nanoparticles. Density functional theory (DFT) calculations indicate that Ag nanoparticles supported on M-CeO2 could facilitate the formation of oxygen vacancies, which result in higher CO2 adsorption capacity. With the most oxygen vacancies and the well-dispersed Ag active species, Ag (3.12 %)/M-CeO2 exhibits high efficiency for the carboxylative coupling of terminal alkynes, chloride compounds and CO2 under mild reaction conditions (60 degrees C, 0.5 MPa), affording a wide range of functionalized 2-alkynoates in good yields.