Room temperature synthesis of Cu(Qc)2 and its application for ethane capture from light hydrocarbons

Abstract A facile and efficient room-temperature synthesis approach was proposed to prepare MOF material Cu(Qc)2 (henceforth called RT-Cu(Qc)2) with ultramicropores. RT-Cu(Qc)2 was successfully synthesized at room-temperature by means of (Zn, Cu) hydroxyl double salt as intermediate within 1-12 hours. The resulting RT-Cu(Qc)2 exhibited excellent water vapor stability and its C2H6 uptake reached 2.19 mmol/g at 288K and 1 bar. Its C2H6/C2H4 and C2H6/CH4 uptake ratio at 298 K and 1 bar were up to 3.70 and 22.67, superior to benchmark MAF-49, Cu(Qc)2 and ZIF-7. Its IAST-predicted C2H6/C2H4 and C2H6/CH4 selectivity reached 4.1 (1:1 v:v) and 35.9 (1:9 v:v) at 288 K and 1 bar, higher than most of ethane-capturing MOFs. Molecular simulation revealed well-defined host-guest match between Cu(Qc)2 and ethane. Fixed bed experiments confirmed that ethane/ethylene or ethane/methane mixtures can be completely separated using RT-Cu(Qc)2. RT-Cu(Qc)2 has great potential for separation of ethane/ethylene and the recovery of ethane from natural gas.