Tuning Pore Size in Square‐Lattice Coordination Networks for Size‐Selective Sieving of CO2

• DOI: 10.1002/anie.201603934
• Publication Date: 2016-07-21T09:48:21Z
• Authors: Kai‐Jie Chen; David G. Madden; Tony Pham; Katherine A. Forrest; Amrit Kumar; Qing‐Yuan Yang; Wei Xue; Brian Space; John J. Perry; Jie‐Peng Zhang; Xiao‐Ming Chen; Michael J. Zaworotko
• Keywords: 02 engineering and technology; 0210 nano-technology; 01 natural sciences; 0104 chemical sciences

AbstractPorous materials capable of selectively capturing CO2 from flue‐gases or natural gas are of interest in terms of rising atmospheric CO2 levels and methane purification. Size‐exclusive sieving of CO2 over CH4 and N2 has rarely been achieved. Herein we show that a crystal engineering approach to tuning of pore‐size in a coordination network, [Cu(quinoline‐5‐carboxyate)2]n (Qc‐5‐Cu) ena+bles ultra‐high selectivity for CO2 over N2 (SCN≈40 000) and CH4 (SCM≈3300). Qc‐5‐Cu‐sql‐β, a narrow pore polymorph of the square lattice (sql) coordination network Qc‐5‐Cu‐sql‐α, adsorbs CO2 while excluding both CH4 and N2. Experimental measurements and molecular modeling validate and explain the performance. Qc‐5‐Cu‐sql‐β is stable to moisture and its separation performance is unaffected by humidity.