Benchmark C2H2/CO2 Separation in an Ultramicroporous Metal-Organic Framework via Copper(I)-Alkynyl Chemistry

Angew Chem Int Ed Engl. 2021 May 12. doi: 10.1002/anie.202102810. Online ahead of print.ABSTRACTSeparation of acetylene from carbon dioxide remains a daunting challenge because of their very similar molecular sizes and physical properties. We herein report the first example of using copper(I)-alkynyl chemistry within an ultramicroporous MOF (CuI@UiO-66-(COOH)2) to achieve ultrahigh C2H2/CO2 separation selectivity. The anchored Cu(I) ions on the pore surfaces can specifically and strongly interact with C2H2 molecule through copper(I)-alkynyl π-complexation and thus rapidly adsorb large amount of C2H2 at low-pressure region, while effectively reduce CO2 uptake due to the small pore sizes. This material thus exhibits the record high C2H2/CO2 selectivity of 185 at ambient conditions, significantly higher than the previous benchmark ZJU-74a (36.5) and ATC-Cu (53.6). Theoretical calculations reveal that the unique π-complexation between Cu(I) and C2H2 mainly contributes to the ultrastrong C2H2 binding affinity and record selectivity. The exceptional separation performance was evidenced by breakthrough experiments for C2H2/CO2 gas mixtures. This work suggests a new perspective to functionalizing MOFs with copper(I)-alkynyl chemistry for highly selective separation of C2H2 over CO2.PMID:33977622 | DOI:10.1002/anie.202102810

Source: Angewandte Chemie - May 12, 2021 Category: Chemistry Authors: Banglin Chen Ling Zhang Ke Jiang Lifeng Yang Libo Li Enlai Hu Ling Yang Kai Shao Huabin Xing Yu Yang Yuanjing Cui Bin Li Guodong Qian Source Type: research