Fine-Tuning the Pore Environment of the Microporous Cu-MOF for High Propylene Storage and Efficient Separation of Light Hydrocarbons.

Ethylene (CH) and propylene (CH) are important energy sources and raw materials in the chemical industry. Storage and separation of CH and CH are vital to their practical application. Metal-organic frameworks (MOFs) having adjustable structures and pore environments are promising candidates for CH/CH separation. Herein, we obtained a Cu-based MOF synthesized by HTTCA and pyrazine ligands. By adding different functional groups on the ligands within the MOFs, their pore environments are adjusted, and thus, the CH storage capacity and CH/CH separation efficiency are improved. Eventually, the fluoro- and methyl-functionalized exhibits a better gas storage and CH/CH separation performance compared with (nonfunctionalized), (fluoro-functionalized), and (methyl-functionalized). A record-high CH uptake of 293.6 ± 2.3 cm g (273 K, 1 atm) is achieved using . Moreover, shows excellent repeatability, and only 3.5% of CH storage capacities decrease after nine cycles. Employing Grand Canonical Monte Carlo (GCMC) simulations, it is indicated that preferentially adsorbs CH rather than CH at low pressure. Single-crystal X-ray diffraction on CH-adsorbed crystals precisely demonstrates the adsorption positions and arrangement of CH molecules in the framework, which is consistent with the theoretical simulations. Remarkably, gas sorption isotherms, molecular simulations, and breakthrough experiments comprehensively demonstrate that this unique MOF material exhibits highly efficient CH/CH separation. Additionally, also possesses efficient separation of CH/CH and CH/CH, indicating its promising potential in storage/separation of light hydrocarbons in industry.