Cycloaddition of CO2 and epoxides over a porous covalent triazine-based polymer incorporated with Fe3O4

초록

A highly porous quaterphenyl-containing covalent triazine polymer (QP-CTP) incorporated with iron oxide nanoparticles (Fe3O4@QP-CTP) was synthesized and applied as a catalyst for the cycloaddition of CO2 and epoxides under mild conditions. The synthesized materials were characterized using X-ray powder diffraction, N-2 adsorption-desorption isotherm, X-ray photoelectron spectroscopy, transmission electron microscopy, and elemental analysis. The Fe3O4@QP-CTP composite in the presence of tetrabutyl-ammonium bromide showed 95% conversion of epoxides with high selectivity to cyclic carbonates at 50 degrees C, 0.1 MPa CO2 in 12 h. The reaction kinetics was further improved upon increasing the temperature to 80 degrees C. The catalyst was easily recovered using a magnet, and its stability was confirmed using a recycle test, which showed that the catalyst could be re-used for a minimum of eight consecutive runs without a noticeable decline in catalytic activity. A plausible mechanistic pathway of the cycloaddition reaction over Fe3O4@QP-CTP was also proposed.

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