Room-Temperature Synthesis of Pyr_1/3@Cu–BTC with Enhanced Stability and Its Excellent Performance for Separation of Propylene/Propane

It is critical to enhance further the stability and adsorption selectivity of MOFs for promoting applications of MOFs. Herein, we proposed an effective bifunctional SBU-tuning strategy to synthesize novel Pyr_1/3@Cu–BTC for the separation of propylene/propane. Pyr@ Cu–BTC was synthesized by grafting of pyrrole onto Cu–BTC. Its water vapor stability and separation property were then examined. The resulting Pyr_1/3@Cu–BTC showed not only enhanced water vapor stability but also superhigh C₃H₆ adsorption capacity as well as C₃H₆/C₃H₈ selectivity at 1 bar and 298 K, reaching 7.60 mmol/g and 8.3 separately, much higher than most MOFs. Experiments of water vapor stability indicated that after being placed under humid air (RH of 55%) for 20 days, Pyr_1/3@Cu–BTC still retained its crystalline structure. The application of the fixed bed of Pyr_1/3@Cu–BTC could completely separate C₃H₆ and C₃H₈ from their mixture at ambient conditions. Pyr_1/3@Cu–BTC is promising for the separation of propylene/propane or propylene recovery from dry gas.