Tuning Pore Environment via Pendant Alkyl/Hydroxyalkyl Groups in Robust Channel-Interpenetrated Metal–Organic Frameworks for Enhanced Propylene Purification at Elevated Temperatures

Efficient purification of propylene from propane at elevated temperatures is desirable but necessitates porous adsorbents with tunable pore environments. Herein, we modulate pore environments by varying dangling groups X (–CH(CH3)OH, −CH2OH, –CH2CH3) in robust channel-interpenetrated MOFs (Zn3-X). Zn3-CH2OH (strongest polarity, widest pores) exhibits high propylene uptake (66.8 cm3 g−1) but low static (2.9) and kinetic (1.1) selectivities at 298 K; Zn3-CH2CH3 (largest steric hindrance and narrowest pores) yields the lowest uptake (31.4 cm3 g−1). Remarkably, Zn3-CH(CH3)OH (moderate pore polarity and aperture) affords an appropriate uptake (61.3 cm3 g−1) and static (5.0) and kinetic (1.3) selectivities. This tunable pore environment facilitates optimal host–guest interactions, as corroborated by computational modeling. Breakthrough experiments confirm that Zn3-CH(CH3)OH delivers higher productivity of propylene at 323 K than at 298 K (0.065 vs 0.033 mL g−1 min−1) in a single cycle. The excellent stability and tunable pore environments enable enhanced propylene purification at elevated temperatures, offering valuable insights for high-temperature gas separation.