Hierarchical Porous and Zinc-Ion-Crosslinked PIM-1 Nanocomposite as a CO Cycloaddition Catalyst with High Efficiency.

CO cycloaddition to epoxides is an effective and economical utilization method to alleviate the current excessive CO emission situation. The development of catalysts with both high catalytic efficiency and high recyclability is necessary but challenging. In this context, a heterogeneous catalyst was synthesized based on a zinc-ion-crosslinked polymer with intrinsic microporosity (PIM-1). The high microporosity of PIM-1 promoted a high Zn loading rate. Additionally, the relatively stable ionic bond formed between Zn and the PIM-1 framework through electrostatic interaction ensured high loading stability. In the process of CO cycloaddition with propylene epoxide, an optimized conversion of 90 % with a turnover frequency as high as 9533 h could be achieved within 0.5 h at 100 °C and 2 MPa. After 15 cycles, the catalytic efficiency did not demonstrate a significant decline, and the catalyst was able to recover most of its activity after Zn reloading. This work thereby provides a strategically designed CO conversion catalyst based on an ionic crosslinked polymer with intrinsic microporosity.