Design of Zeolitic Imidazolate Framework Derived Nitrogen‐Doped Nanoporous Carbons Containing Metal Species for Carbon Dioxide Fixation Reactions

• DOI: 10.1002/cssc.201500780
• Publication Date: 2015-09-23T13:10:41Z
• Authors: Takashi Toyao; Mika Fujiwaki; Kenta Miyahara; Tae‐Ho Kim; Yu Horiuchi; Masaya Matsuoka
• Keywords: 2. Zero hunger; Nitrogen; Carbonates; Imidazoles; 02 engineering and technology; Carbon Dioxide; 01 natural sciences; Carbon; Catalysis; 3. Good health; 0104 chemical sciences; Zeolites; Nanotechnology; 0210 nano-technology; Porosity

AbstractVarious N‐doped nanoporous carbons containing metal species were prepared by direct thermal conversion of zeolitic imidazolate frameworks (ZIFs; ZIF‐7, ‐8, ‐9, and ‐67) at different temperatures (600, 800, and 1000 °C). These materials were utilized as bifunctional acid–base catalysts to promote the reaction of CO2 with epoxides to form cyclic carbonates under 0.6 MPa of CO2 at 80 °C. The catalyst generated by thermal conversion of ZIF‐9 at 600 °C (C600‐ZIF‐9) was found to exhibit a higher catalytic activity than the other ZIFs, other conventional catalysts, and other metal–organic framework catalysts. The results of various characterization techniques including elemental analysis, X‐ray diffraction, X‐ray photoelectron spectroscopy, X‐ray absorption spectroscopy, and transmission electron microscopy show that C600‐ZIF‐9 contains partly oxidized Co nanoparticles and N species. Temperature‐programmed desorption measurements by using CO2 and NH3 as probe molecules revealed that C600‐ZIF‐9 has both Lewis acid and Lewis base catalytic sites. Finally, the substrate scope was extended to seven other kinds of epoxides.