High-Throughput Screening of Anion-Pillared Metal–Organic Frameworks for the Separation of Light Hydrocarbons

Separation of light hydrocarbons is a challenging and energy-intensive industrial process. Adsorptive separations using metal–organic frameworks (MOFs) have drawn attention because they offer a potential route to higher energy efficiency for these separations. In this work, we performed high-throughput screening for the separations of C1–C3 light hydrocarbons based on adsorption in our previously reported anion-pillared MOF database. We explored the relationships of selectivity in the dilute limit with physical parameters including the largest cavity diameter, surface area, and pore volume fraction of MOFs. On the basis of this screening, we assessed the selective adsorption of binary light hydrocarbon mixtures for some promising MOFs by GCMC simulations and compared the selectivities with those of previously reported sorbent materials. We observed a trade-off between two performance metrics in which MOFs with higher selectivity usually show lower working capacity. When the pore space is available to both components, the vdW interaction plays a dominant role in light hydrocarbon separations. However, if the pore sizes are too small, separation is possible based on molecular sieving. The comparisons with some reported porous materials indicate that SIFSIX-2-Ni-i, SIFSIX-6-Cd-i, InFFIVE-5-Zn-i, and GaFFIVE-5-Cd-i appear promising for C3H6/C3H8, C2H6/CH4, C3H6/C2H4, and C3H8/C2H4 separations, respectively.