Postsynthetic Lithium Modification of Covalent-Organic Polymers for Enhancing Hydrogen and Carbon Dioxide Storage

Abstract

Recent experiment and simulation show that introduction of lithium in the frameworks can enhance the gasstorage capacities of framework materials. Here a covalentorganic polymer-1 (COP-1) has been synthesized through the self-polymerization of monomer 1,3,5-tris((4-bromophenyl)ethynyl) benzene (TBEB) by the nickel(0)-catalyzed Yamomoto reaction. To enhance gas adsorption properties of the COP-1 material, we have proposed a novel lithium-decorating approach in which the alkynyl functionalities in COP-1 are postsynthetically converted to lithium carboxylate groups with the aid of dry ultrapure CO 2 . In particular, the H 2 uptake of lithium-modified COP material is 1.67 wt % at T = 77 K and ∼1 bar, which is increased by ∼70.4%, compared with the unmodified compounds. Besides, the enhancement effects of lithium modification on CO 2 and CH 4 adsorption have also been observed. It is expected that this approach proposed here would provide a new direction for lithium modification of MOFs and COFs for clean energy and environmental applications.

Bifunctionalized conjugated microporous polymers for carbon dioxide capture

“…Both of the polymer networks exhibited low gas coverage enthalpies of adsorption of around 7.8 kJ/mol (Fig. S7), which is comparable to the nonfunctionalized CMPs (7À10 kJ/mol) [36], the lithium doped CMP (8.1 kJ/mol) [46], the lithium modified covalent-organic polymer (~7.6 kJ/mol) [47], the porous benzimidazole-linked polymer (7.9e8.3 kJ/mol) [48], and the nanoporous azo-linked polymers (7.5e8.0 kJ/mol) [34]. The CO 2 uptakes of the polymer networks were measured up to 1.13 bar at 273 and 298 K, respectively (Fig.…”

Copper‐Free Sonogashira Coupling for High‐Surface‐Area Conjugated Microporous Poly(aryleneethynylene) Networks

“…to produce conjugated microporous poly(aryleneethynylene) networks (CMPs) is a commonly employed method to incorporate functional groups into porous polymer backbones . Further functional groups can be grafted onto the polymer backbones postsynthetically . The importance of these materials is emphasized by the recent commercialization of CMP‐1 by Sigma–Aldrich…”

Methyllithium‐Doped Naphthyl‐Containing Conjugated Microporous Polymer with Enhanced Hydrogen Storage Performance

“…As shown in Figure B, the signals of chemical shift at δ= 126.0 and 132.9 ppm suggested the presence of a phenyl and a naphthyl group . The signal located at δ= 91.6 ppm is indicative of the acetylene group . The 7 Li NMR spectra of MeLi@N‐CMP and Li@N‐CMP (Figure C) were characterized by signals located at δ =−0.49 and −0.94 ppm, respectively, the typical region of lithium alkyls and lithium cations, indicating the different chemical environment and average electronic density…”