Enhancing Higher Hydrocarbons Capture for Natural Gas Upgrading by Tuning van der Waals Interactions in fcu-Type Zr-MOFs

Higher hydrocarbons in natural gas must be removed for safe storage, transport, and application of natural gas. Considering C3H8 and CH4 are nonpolar molecules, electrostatic interactions between C3 and MOFs are relatively weak, while they could be sensitive to the van der Waals interactions. Thus, it is an effective method to greatly enhance the separation performance by improving the van der Waals interactions through tuning the pore size of MOFs. Herein, we synthesized a series of isostructural Zr-MOFs with different pore sizes, and the separation performances of these materials for C3/C1 were systematically studied. The results indicate that pore size plays an important role in the C3 storage and C3/C1 separation in MOFs. Specifically, Zr-BPDC with large surface area and pore volume has the highest C3H8 and C3H6 adsorption capacity (159.2 cc/g and 161.5 cc/g at 298 K 1 bar, respectively), while Zr-FUM with the smallest surface area and pore volume has the highest adsorption heat for C3 as well as C3/C...