A Novel Strategy to Enhance the Performance of CO₂ Adsorption Separation: Grafting Hyper-cross-linked Polyimide onto Composites of UiO-66-NH₂ and GO

Abstract

Graphene oxide (GO) is widely used to improve the pore structure, dispersion capacity, adsorption selectivity, resistance to acids and bases, and thermal stability of metal–organic frameworks (MOFs). However, it remains a daunting challenge to enhance selectivity simply by modifying the pore surface polarity and producing a suitable pore structure for CO2 molecules through a combination of GO with MOFs. Herein, we demonstrate a novel porous hyper-cross-linked polyimide–UiO–graphene composite adsorbent for CO2 capture via in situ chemical knitting and condensation reactions. Specifically, a network of polyimides rich in carbonyl and nitrogen atoms with amino terminations was synthesized via the reaction of 4,4′-oxydiphthalic anhydride (ODPA) and 2,4,6-trimethyl-1,3-phenylenediamine (DAM). The product plays a crucial role in the separation of CO2 from N2. As expected, the resulting composite (PI-UiO/GO-1) exhibited a 3-fold higher CO2 capacity (8.24 vs 2.8 mmol·g–1 at 298 K and 30 bar), 4.2 times higher CO2/N2 selectivity (64.71 vs 15.43), and significantly improved acid–base resistance stability compared with those values of pristine UiO-66-NH2. Furthermore, breakthrough experiments verified that the porous composites can effectively separate CO2 from simulated fuel gas (CO2/N2 = 15/85 vol %) with great potential in industrial applications. More importantly, this strategy can be extended to prepare other MOF-based composites. This clearly advances the development of MOF–polymer materials for gas capture.

Preparation of Activated Carbon Doped with Graphene Oxide Porous Materials and Their High Gas Adsorption Performance

“…The nitrogen adsorption–desorption isotherm of CAC-0 belongs to type I­(a). Its isotherm reaches equilibrium at a low relative pressure (about 0.1), which is typical microporous adsorption . With the addition of GO, the adsorption isotherm from CAC-1 to CAC-50 changed to type I­(b), and there were weak hysteresis loops.…”

“…Its isotherm reaches equilibrium at a low relative pressure (about 0.1), which is typical microporous adsorption. 35 With the addition of GO, the adsorption isotherm from CAC-1 to CAC-50 changed to type I(b), and there were weak hysteresis loops. It shows that the composite has mesoporous structures, and the pore size is very close to the micropore, which is a typical micro-mesoporous structure.…”

Application of Metal-Organic Framework-Based Composites for Gas Sensing and Effects of Synthesis Strategies on Gas-Sensitive Performance

“…The highest yield of this composite was 84% when all the above three conditions were met optimally. Ning et al [201] synthesized a super-crosslinked polyimide-UiO-graphene composite (PI-UiO/GO) by chemical in situ braiding and condensation reaction. As shown in Figure 22, the carbonyl, N atom, oxygen atom, and -NH-(primary amine) in the polyimide are the adsorption sites for CO 2 .…”

Influence of ultra-micropore volume of activated carbons prepared from noble mung bean on the adsorption properties of CO2, CH4, and N2

“…On the other hand, adsorption has been in the limelight for more than ten years as a promising technology for separating CO 2 from gas mixtures, including biogas, due to its low maintenance cost, easy operation, and low energy requirement. [6][7][8] Research and development activities have been traditionally conducted to produce adsorbents from agricultural by-products or agricultural waste to design and develop adsorption-based gas/liquid separation processes. [9][10][11][12] The method of converting agricultural waste resources into useful substances has many scientific implications regarding environmental pollution prevention and resource circulation.…”

“…On the other hand, adsorption has been in the limelight for more than ten years as a promising technology for separating CO 2 from gas mixtures, including biogas, due to its low maintenance cost, easy operation, and low energy requirement. 6–8…”