Summary
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 h. The resulting RT-Cu(Qc)(2) exhibited excellent water vapor stability and its C2H6 uptake reached 2.19 mmol/g at 288 K 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.