Fig. 2. (a) Catalytic performance of ionic POFs and Zn/POFs in the cycloaddition of CO₂ and propylene oxide: the substrate scope, percentage of conversion, and isolated yields are indicated. Epoxide (17.2 mmol), TBAB (cocatalyst, 2.5 mol%, 0.43 mmol), catalyst (POF or Zn/POF: 2 wt%, 20 mg), CO₂ (2.5 bar), 90 °C and 9 h. The substrate scope was explored employing Zn/POF2 (20 mg) as the catalyst. % of conversion was determined by the ¹H NMR analysis of the reaction mixture with 1,1,2,2-tetrachloroethane as an external standard. (b) Recyclability of Zn/POF2 after catalytic cycloaddition reaction between propylene oxide and CO₂ by maintaining a fixed amount of catalyst of 20 mg, circumventing the weight loss (1–1.5 mg per cycle) during the recovery process; more than 90% conversion for multiple cycles ascertain no loss in catalytic efficiency. (c) The PXRD profiles of the pristine and regenerated catalysts demonstrating the robustness of Zn/POF2 in catalytic CO₂ conversion.