Restrictive Regulation of Ionic Liquid Quaternary Ammonium Salt in SBA‐15 Pore Channel for Efficient Carbon Dioxide Conversion

• Published in: Chemistry : a European journal 2022-11, Vol.28 (66), p.e202202105-n/a
• Main Authors: Liu, Shaoqing, Hou, Xueyan, Xu, Aihao, Chu, Bingxian, Li, Yunxi, Jin, Lijian, Lu, Jinkai, Dong, Lihui, Fan, Minguang
• Format: Article
• Language: English
• Subjects: Ammonium; Ammonium salts; Carbon dioxide; Carbon fixation; Catalysts; Catalytic activity; Channels; Chemical synthesis; Chemistry; Conversion; Cycloaddition; Cycloaddition reaction; Density functional theory; DFT; Epoxides; Grafting; Immobilization; Ionic liquid; Ionic liquids; Quaternary ammonium salts; Reaction mechanisms; SBA-15
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.202202105

Herein, the synthesis of a new type of catalyst, SBA−M (Schiff complex of different metal types grafted on SBA‐15) based on a quaternization reaction, is described. Various amounts of ionic liquid were grafted into the pore channels of SBA‐15 using the post‐grafting method, which allowed the ionic liquid to be grafted into the pore channels restrictively. Notably, over six cycles, SBA−Mn (0.2) has been shown to maintain its catalytic activity and stability. In addition, a reaction mechanism for the cycloaddition of CO2 with epoxides based on density‐functional theory is proposed. The cycloaddition reaction of CO2 and epoxides is an efficient way of carbon fixation. It is demonstrated that the metal coordinated with the oxygen atom of the epoxides and that a halogen attacked the carbon of epoxides. Moreover, theoretical calculations and synthesis strategy provide a new approach for CO2 conversion. SBA‐15 with metal based quaternary ammonium salt was used for the cycloaddition of CO2 with epoxides. Ionic liquids grafting into the pore channel of SBA‐15 provide an alternative chance to improve the catalytic performance at 1.5 MPa and 90 °C.