A MOF built on 8-connected Y3 nodes demonstrates simultaneous reverse adsorptive separation: ethane over ethylene and propane over propylene
摘要
Selective adsorption of paraffins over olefins (mostly C2 and C3) by porous solids could offer tremendous advantages for the purification of olefins, which is, however, challenging as it has stringent requirements on the pore dimensions and pore surface chemistry of the adsorbent. We report here a metal-organic framework (MOF) with novel topology, Y3(μ3-OH)(TCMPB)2 (denoted as HIAM-316, TCMPB4− = 1,2,4,5-tetra(4-carboxy-3-methylphenyl)benzene), which shows reversed separation of C2H6/C2H4 and C3H8/C3H6 simultaneously. The ideal adsorbed solution theory (IAST) selectivities for equimolar binary mixtures of C2H6/C2H4 and C3H8/C3H6 were calculated to be 1.67 and 1.23 at 1 bar and 298 K for HIAM-316. Its capability of removing paraffines from paraffin/olefin mixtures is validated by breakthrough measurements. Molecular simulations reveal that the preferential adsorption of paraffins over olefins by HIAM-316 may be attributed to the abundant carboxylate oxygen atoms along its channel.