One-step purification of ethylene from ethane/ethylene mixtures by a stable vanadium-based metal-organic framework

The efficient separation of ethylene (C2H4) from ethane/ethylene (C2H6/C2H4) mixtures, achieved via a singlestep selective adsorption process, represents a promising yet challenging goal. Notably, the pursuit of adsorbents that combine high adsorption capacity with low adsorption heat is paramount, as these attributes directly correlate with superior separation efficiency and minimized regeneration energy. In this study, we present the selective adsorption of C2H6 over C2H4 by a V-MOF (V-TBAPy), constructed from [V(mu 2-O)O4]n secondary building units. The pore surface of V-TBAPy is characterized by a high density of aromatic rings and oxygen atoms, which facilitates targeted adsorption of C2H6 through C-H center dot center dot center dot pi and C-H center dot center dot center dot O interactions. V-TBAPy adsorbs up to 102.6 cm3/g of C2H6 at 298 K and 1 bar, with a selectivity of 1.66 for an equimolar C2H6/C2H4 binary mixture. Importantly, the adsorption heat for C2H6 on V-TBAPy is as low as 22.7 kJ/mol, enabling energyefficient regeneration. Breakthrough experiments have confirmed the efficacy of V-TBAPy in achieving onestep purification of C2H6/C2H4 mixtures in conditions mimicking industrial settings.