Synthesis of a porous organic polymer via click reaction for efficient CH4/C2H6/C3H8 separation

Abstract

Adsorptive separation holds important prospect for the challenging recovery of C₂H₆ and C₃H₈ from natural gas and the separation efficiency is primarily determined by a high-performance adsorbent. In this work, we reported the synthesis of a novel porous organic polymer, FOSU-POP-1 for the separation of CH₄/C₂H₆/C₃H₈. The FOSU-POP-1 was synthesized from tetrakis(4-azidophenyl)methane and 1,3,5-triethynylbenzene via click reaction with a Brunauer–Emmett–Teller (BET) surface area of 1038 m²·g⁻¹. Exhibiting stronger affinity towards C₃H₈ and C₂H₆ than CH₄, 2.85 mmol·g⁻¹ for C₃H₈ and 2.14 mmol·g⁻¹ for C₂H₆ were achieved on the FOSU-POP-1 at 0.1 MPa, 298 K, with an ideal adsorbed solution theory selectivity of 227 for C₃H₈/CH₄. The breakthrough experiment confirmed the good dynamic separation performance and recyclability of FOSU-POP-1 for CH₄/C₂H₆/C₃H₈ ternary mixture. The density functional theory calculation further revealed that the N atom in triazole ring interacted strongly with the C₃H₈ and C₂H₆. This work highlighted the promising capability of FOSU-POP-1 for efficiently separating CH₄/C₂H₆/C₃H₈ mixture.