A chemically stable nanoporous coordination polymer with fixed and free Cu2+ ions for boosted C2H2/CO2 separation

Abstract

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 42 (v/v: 1/4) at low pressure under 298 K, along with enhanced C 2 H 2 capacity (from 89.22 to 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.

An Unprecedented Pillar‐Cage Fluorinated Hybrid Porous Framework with Highly Efficient Acetylene Storage and Separation

“…[10] Hence, rational synthesis of cage-like MOFs with small windows may realize high adsorption capacity and high separation selectivity simultaneously. It is familiar that the combination of 3-connected triangular organic ligands and 4connected square metal nodes will form the (3,4)-connected pto frameworks (Scheme 1 b). Considering that there are still two uncoordinated sites at the axial direction of the metal node, rational selection of a second linear ligand such as SiF 6 2À groups to cross-link two adjacent square metal nodes can lead to the (3,6)-connected ith-d framework.…”

Dynamic Pendulum Effect of an Exceptionally Flexible Pillared‐Layer Metal‐Organic Framework†

“…Porous coordination polymers (PCPs) or metal–organic frameworks (MOFs) are attractive for their high crystallinity, structural diversity and modular designability, [ 9‐11 ] and great efforts have been devoted to the design, preparation and application of MOFs. [ 12‐27 ] Thanks to the assembly via relatively weak and sensitive coordination bonds, a few MOFs exhibit distinctive framework flexibilities and stimuli‐responsive performances including breathing behaviors, gate opening transformations, hysteresis and multi‐ step sorption behaviors, even shape‐memory effect. [ 28‐32 ] Such structural transformations of flexible MOFs induced by external physical or chemical stimuli indicate a great potential application in the field of artificial molecular machines, whose long‐range order can help to bridge the gap between complex motions on molecular level and the responsive behaviors of the macroscopic solid materials.…”

Terminal and Internal Alkyne Complexes and Azide-Alkyne Cycloaddition Chemistry of Copper(I) Supported by a Fluorinated Bis(pyrazolyl)borate

“…Copper based materials are also useful for the separation of acetylene from CO 2 and acetylene storage [33][34][35][36][37]. Copper alkyne or alkynide complexes [38] are believed to be key intermediates in many of these reactions.…”