Three-way ROD metal-organic frameworks for natural gas upgrading

Abstract

The reticular chemistry of rod MOFs has attracted increasing attention from structures to applications. Herein, a series of MOF materials along with unique 3-way rod secondary building units were thoroughly prepared according to our previous work (3W-ROD-2-OH, 3W-ROD-2-F, 3W-ROD-2-CH3). Thanks to their unique structural features, 3W-ROD-2-X exhibited relatively high adsorption capacities for C3H8 (8.53∼8.74 mmol/g), C2H6 (3.40∼3.69 mmol/g), and CO2 (1.94∼2.15 mmol/g), over CH4 (0.42∼0.45 mmol/g) at 298 K and 1 bar. The adsorption selectivities of C3H8/CH4, C2H6/CH4, and CO2/CH4 were calculated by IAST. The selectivities were 53.7∼70.9 (C3H8/CH4 = 15:85), 8.9∼11 (C2H6/CH4 = 15:85) and 5.3∼7.0 (CO2/CH4 = 15:85), respectively. Meanwhile, dynamic breakthrough experiments proved that 3W-ROD-2-CH3 showed separation property toward C3H8/CH4, C2H6/CH4, and CO2/CH4. The results indicate that the materials have the potential for natural gas upgrading.