Polyamine-Tethered Porous Polymer Networks for Carbon Dioxide Capture from Flue Gas

Post-metalation of porous aromatic frameworks for highly efficient carbon capture from CO2 + N2 and CH4 + N2 mixtures

“Light metal, strong power”: new porous aromatic frameworks (PAF-26) with available carboxyl groups are synthesized and further modified with light metal ions (Li⁺, Na⁺, K⁺, Mg²⁺); the metalized PAF-26 shows a distinct enhancement for CO₂ and CH₄ uptake.

Metal-organic frameworks capable of healing at low temperatures

Filling crystalline gaps with small molecules can drive interfacial healing between anisotropic solids. Sufficient mobility from these fillers allows the process to happen at a low temperature of -56 °C. Mended bulk crystals show modulus leap from 4 to 12 GPa and hardness from 400 to 1000 MPa.

CO₂ Separation and Capture Properties of Porous Carbonaceous Materials from Leather Residues

Carbonaceous porous materials derived from leather skin residues have been found to have excellent CO₂ adsorption properties, with interestingly high gas selectivities for CO₂ (α > 200 at a gas composition of 15% CO₂/85% N₂, 273K, 1 bar) and capacities (>2 mmol·g⁻¹ at 273 K). Both CO₂ isotherms and the high heat of adsorption pointed to the presence of strong binding sites for CO₂ which may be correlated with both: N content in the leather residues and ultrasmall pore sizes.

Targeted synthesis of electroactive porous organic frameworks containing triphenyl phosphine moieties

A novel electroactive porous aromatic framework (JUC-Z4-Cl) was designed and synthesized via Yamamoto-type Ullmann cross-coupling reaction with the monomer tris(4-chlorophenyl)phosphine. By simple redox chemical reactions, stable, reductive, porous polytri(p-phenyl)phosphine (JUC-Z4) and polytri(p-phenyl)phosphine oxide (JUC-Z5) could be obtained as off-white powders. The structures of JUC-Z4 and JUC-Z5 were confirmed using magic-angle spinning nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, etc. The microporous architectures exhibit high stability (471°C for JUC-Z4 and 484°C for JUC-Z5) and large surface area (793 and 648 m² g⁻¹ for JUC-Z4 and JUC-Z5, respectively). JUC-Z4 also exhibits efficient recognition ability of greenhouse gases from dry air.

Microporous organic polymers for gas storage and separation applications

Microporous organic polymers (MOPs), an emerging class of functional porous materials featured with the pure organic component have been widely studied in recent years. These materials have potential uses in areas such as storage, separation, and catalysis. In this Perspective, we focused on the gas storage and separation of MOPs. The targeted design and synthesis of MOPs toward the enhancement of gas capacity and selectivity are discussed. Furthermore, special emphasis is given to the post-synthesis modification of MOPs which have been proved to be effective methods to accurately tune the desired properties.

Efficient CO2 Capture by a 3D Porous Polymer Derived from Tröger's Base

A 3D Tröger's-base-derived microporous organic polymer with a high surface area and good thermal stability was facilely synthesized from a one-pot metal-free polymerization reaction between dimethoxymethane and triaminotriptycene. The obtained material displays excellent CO₂ uptake abilities as well as good adsorption selectivity for CO₂ over N₂. The CO₂ storage can reach up to 4.05 mmol g^-1 (17.8 wt %) and 2.57 mmol g^-1 (11.3 wt %) at 273 K and 298 K, respectively. Moreover, the high selectivity of the polymer toward CO₂ over N₂ (50.6, 298 K) makes it a promising material for potential application in CO₂ separation from flue gas.

Fluorinated Porous Organic Polymers via Direct C-H Arylation Polycondensation

Considering the high reactivity of the C-H bonds in fluorobenzenes for direct arylation and special properties of fluorinated polymers, herein, synthesis of fluorinated porous organic polymers via direct C-H arylation polycondensation is explored. The obtained polymers (FPOP-1 and FPOP-2) are well characterized and show high porosities with Brunauer-Emmett-Teller specific surface area of above 1000 m² g^-1. Different pore size distribution (PSD) profiles of porous polymers can be obtained by selecting different core constructing monomers. FPOP-2 exhibits a relatively narrower PSD with the dominant pore size at about 0.63 nm, which is more suitable for adsorption of small gas molecules (H₂, CO₂, and CH₄) than FPOP-1. As a porous fluorinated hydrophobic material, FPOP-2 possesses high adsorption ability for toluene (976 mg g^-1 at saturated vapor pressure and room temperature) due to its high porosities and binding affinities between the guest molecules and the host network. The good sorption capacity of FPOP-2 for toluene makes it show potential applications in elimination of harmful small aromatic molecules in the environment.

Reversible CO2 adsorption by an activated nitrogen doped graphene/polyaniline material

For effective adsorption of carbon dioxide (CO2), we investigate a porous N functionalized graphene adsorbent produced by the chemical activation of a reduced graphene oxide/polyaniline composite. The N-doped graphene composite is microporous with a maximum BET surface area of 1336 m(2) g(-1). It shows a highly reversible maximum CO2 storage capacity of 2.7 mmol g(-1) at 298 K and 1 atm (5.8 mmol g(-1) at 273 K and 1 atm). The N-doped graphene shows good stability during recycling with only an initial decrease of 10% (3-2.7 mmol g(-1)) in adsorption capacity before attaining a cycling equilibrium. The adsorbance capacity is correlated with N content × pore volume or N content × surface area. Given that there is no proper correlation parameter, these factors can be used to increase the CO2 adsorption capacity of N-doped graphene materials for practical utility. The as synthesized material also displays selectivity towards CO2 adsorption compared to H2, N2, Ar or CH4. The as formed material shows that graphene can be uniformly N-doped using the presented synthetic method.

Nitrogen-rich porous adsorbents for CO2 capture and storage

The construction of physical or chemical adsorbents for CO2 capture and sequestration (CCS) is a vital technology in the interim period on the way towards a sustainable low-carbon future. The search for efficient materials to satisfy the increasing demand for CCS has become extremely important. Porous materials, including porous silica, porous carbons, and newly developed metal-organic frameworks and porous organic polymers, possessing regular and well-defined porous geometry and having a high surface area and pore volume, have been widely studied for separations on laboratory scale. On account of the dipole-quadrupole interactions between the polarizable CO2 molecule and the accessible nitrogen site, the investigations have indicated that the incorporation of accessible nitrogen-donor groups into the pore walls of porous materials can improve the affinity to CO2 and increase the CO2 uptake capacity and selectivity. The CO2 -adsorption process based on solid nitrogen-rich porous adsorbents does generally not require heating of a large amount of water (60-70 wt%) for regeneration, while such a heating approach cannot be avoided in the regeneration of amine-based solution absorption processes. Thus, nitrogen-rich porous adsorbents show good regeneration properties without sacrificing high separation efficiency. As such, nitrogen-rich porous materials as highly promising CO2 adsorbents have been broadly fabricated and intensively investigated. This Focus Review highlights recent significant advances in nitrogen-rich porous materials for CCS.