A chemically stable nanoporous coordination polymer with fixed and free Cu^(2+)ions for boosted C_(2)H_(2)/CO_(2)separation

Safely and highly selective acetylene(C_(2)H_(2))capture is a great challenge,because of its highly explosive nature,as well as its nearly similar molecule size and boiling point toward the main impurity of carbon dioxide(CO_(2)).Adsorption separation has shown a promising future.Herein,a new nanoporous coordination polymer(PCP)adsorbent with fixed and free Cu ions(termed NTU-66-Cu)was prepared through post-synthetic approach via cation exchanging from the pristine NTU-66,an anionic framework with new 3,4,6-c topology and two kinds of cages.The NTU-66-Cu shows significantly improved C_(2)H_(2)/CO_(2)selectivity from 6 to 32(v/v:1/1)or 4 to 4_(2)(v/v:1/4)at low pressure under 298 K,along with enhanced C_(2)H_(2)capacity(from 89.22to 111.53 cm^(3)·g^(-1)).More importantly,this observation was further validated by density functional theory(DFT)calculations and breakthrough experiments under continuous and dynamic conditions.Further,the excellent chemical stability enables this adsorbent to achieve recycle C_(2)H_(2)/CO_(2)separation without loss of C_(2)H_(2)capacity.