Microporous Nitrogen-Rich Polymers via Ullmann Coupling Reaction for Selective Adsorption of C2H2 over CH4

Acetylene purification from methane is challenging in the field of porous organic polymers (POPs). Herein, we have provided one-pot Ullmann coupling reaction to synthesize a series of POPs with rich N-sites, named FJU-POP-n, wherein the low-cost and non-toxic Cu(acac)(2) and environmental-friendly glycerol are employed as catalyst and solvent, respectively. These POPs constructed by aromatic amine and haloarene monomers exhibit different steric configurations and pore sizes. Among these, FJU-POP-4 with abundant N-functional sites and suitable pore size exhibits ultra-high selective separation for C2H2/CH4 (307.1, 50 : 50) at ambient conditions, the highest among the reported MOFs and POPs with nitrogen-sites as only functional species. Dynamic fixed bed breakthrough and regeneration experiments confirm structural stability and reproducibility, indicating their promising application in selective separation.