Nanjing Tech University

About: Nanjing Tech University is a education organization based out in Nanjing, China. It is known for research contribution in the topics: Catalysis & Membrane. The organization has 21827 authors who have published 21794 publications receiving 364050 citations. The organization is also known as: Nangongda & Nánjīng Gōngyè Dàxúe.

Hydroxyl-Exchanged Nanoporous Ionic Copolymer toward Low-Temperature Cycloaddition of Atmospheric Carbon Dioxide into Carbonates

Abstract: An ionic copolymer catalyst with nanopores, large surface area, high ionic density, and superior basicity was prepared via the radical copolymerization of amino-functionalized ionic liquid bromide and divinylbenzene, followed with a hydroxyl exchange for removing bromonium. Evaluated in chemical fixation of CO2 with epoxides into cyclic carbonates in the absence of any solvent and basic additive, the nanoporous copolymer catalyst showed high and stable activity, superior to various control catalysts including the halogen-containing analogue. Further, high yields were obtained over a wide scope of substrates including aliphatic long carbon-chain alkyl epoxides and internal epoxide, even under atmospheric pressure and less than 100 °C for the majority of the substrates. On the basis of in situ Fourier transform infrared (FT-IR) investigation and density functional theory (DFT) calculation for the reaction intermediates, we proposed a possible reaction mechanism accounting for the superior catalytic activity...

Acetalization of carbonyl compounds catalyzed by acidic ionic liquid immobilized on silica gel

Abstract: Imidazolium-silica heterogeneous catalyst (SG-[(CH 2 ) 3 SO 3 H-HIM]HSO 4 ) was prepared by immobilization of acidic ionic liquid 1-(propyl-3-sulfonate) imidazolium hydrosulfate ([(CH 2 ) 3 SO 3 H-HIM]HSO 4 ) on silica–gel using tetraethoxysilane (TEOS) as silica source in this study. The properties of the samples were characterized by FT-IR, SEM and TG/DSC. The results suggested that [(CH 2 ) 3 SO 3 H-HIM]HSO 4 had been successfully immobilized on the surface of silica–gel and the immobilized ionic liquid catalyst SG-[(CH 2 ) 3 SO 3 H-HIM]HSO 4 had good thermal stability. The original smooth surface of silica–gel was covered with [(CH 2 ) 3 SO 3 H-HIM]HSO 4 and a rough surface of SG-[(CH 2 ) 3 SO 3 H-HIM]HSO 4 was formed, but the size of particles had no obvious change. Moreover, SG-[(CH 2 ) 3 SO 3 H-HIM]HSO 4 exhibited high catalytic activity for a series of acetalization and could be recovered easily. After reused for 10 times in the synthesis of benzaldehyde ethanediol acetal, the catalyst could still give satisfactory catalytic activity.