Novel CO2-capture derived from the basic ionic liquids orientated on mesoporous materials

Recent advances in ionic liquids-based hybrid processes for CO2 capture and utilization

CO₂ capture and utilization (CCU) is an effective strategy to mitigate global warming. Absorption, adsorption and membranes are methods used for CO₂ separation and capture, and various catalytic pathways have also been developed for CO₂ utilization. Although widely researched and used in industry, these processes are energy-intensive and this challenge needs to be overcome. To realize further optimization, novel materials and processes are continuously being developed. New generation materials such as ionic liquids (ILs) have shown promising potential for cost-effective CO₂ capture and utilization. This study reviews the current status of ILs-based solvents, adsorbents, membranes, catalysts and their hybrid processes for CO₂ capture and utilization. The special properties of ILs are integrated into new materials through hybridization, which significantly improves the performance in the process of CCU.

Uncovering the Underlying Mechanisms Governing the Solidlike Layering of Ionic Liquids (ILs) on Mica

Significant progress has been made in understanding the IL-solid interface in the past three decades, and a key finding is that ILs can form solidlike layers at the interface. It has been recognized that the electrostatic forces at the solid-IL interface and self-assembly of ILs are key enablers of the IL layering. However, regarding the layering structure of ILs, research from different laboratories is not consistent; i.e., the number of solidlike layers could range from 0 to ∼60, indicating the complexity of the underlying mechanisms and/or the existence of overlooked key parameters. In the current review, we will discuss the underlying mechanisms and key parameters governing the layering of ILs on mica, the most studied model solid. First, we will present the experimental findings from various laboratories, both consistent and contradictory ones, and summarize the current understanding of the governing mechanisms. Then, we will discuss the possible key parameters, including the structure of ILs, surface modification and contamination of mica, and cosolvent impacting the solidlike layering of ILs. Finally, we will discuss future research directions in uncovering the underlying mechanisms.

Hybrid Ionic Liquid–Silica Xerogels Applied in CO2 Capture

The imidazolium-based ionic liquids (ILs) are solvents known for selectively solubilizing CO2 from a gas CH4/CO2 mixture, hence we have produced new hybrid adsorbents by immobilizing two ILs on xerogel silica to obtain a solid–gas system that benefits the ILs’ properties and can be industrially applied in CO2 capture. In this work, the ILs (MeO)3Sipmim.Cl and (MeO)3Sipmim.Tf2N were used at different loadings via the sol–gel process employing a based 1-methyl-3-(3-trimethoxysylilpropyl) imidazolium IL associated to the anion Cl− or Tf2N− as a reactant in the synthesis of silica xerogel. The CO2 adsorption measurements were conducted through pressure and temperature gravimetric analysis (PTGA) using a microbalance. SEM microscopies images have shown that there is an IL limit concentration that can be immobilized (ca. 20%) and that the xerogel particles have a spherical shape with an average size of 20 µm. The adsorbent with 20% IL (MeO)3Sipmim.Cl, SILCLX20, shows greater capacity to absorb CO2, reaching a value of 0.35 g CO2 / g adsorbent at 0.1 MPa (298 K). Surprisingly, the result for xerogel with IL (MeO)3Sipmim.Tf2N shows poor performance, with only 0.05 g CO2 / g absorbed, even having a hydrophobic character which would benefit their interaction with CO2. However, this hydrophobicity could interfere negatively in the xerogel synthesis process. The immobilization of ionic liquids in silica xerogel is an advantageous technique that reduces costs in the use of ILs as they can be used in smaller quantities and can be recycled after CO2 desorption.

Light-Triggered CO2 Breathing Foam via Nonsurfactant High Internal Phase Emulsion

Solid materials for CO₂ capture and storage have attracted enormous attention for gaseous separation, environmental protection, and climate governance. However, their preparation and recovery meet the problems of high energy and financial cost. Herein, a controllable CO₂ capture and storage process is accomplished in an emulsion-templated polymer foam, in which CO₂ is breathed-in under dark and breathed-out under light illumination. Such a process is likely to become a relay of natural CO₂ capture by plants that on the contrary breathe out CO₂ at night. Recyclable CO₂ capture at room temperature and release under light irradiation guarantee its convenient and cost-effective regeneration in industry. Furthermore, CO₂ mixed with CH₄ is successfully separated through this reversible breathing in and out system, which offers great promise for CO₂ enrichment and practical methane purification.

New Solid-Base Cu-MgO for CO2 Capture at 473 K and Removal of Nitrosamine

To fabricate a new solid base with high efficiency in the adsorption of CO₂ at 473 K and catalytic activity in the degradation of nitrosamines, magnesium oxalate and copper nitrate are mixed with the assistance of microwave irradiation followed by calcination to immobilize CuO among MgO particles. The binary solid base CuO-MgO is thus moderately reduced to form the Cu-inserted MgO composite with highly exposed strong basic sites, and it can capture 34.6 mg g^-1 of CO₂ in the harsh instantaneous adsorption at 473 K and keep a high strong basicity while trapping the CO₂ mixed with SO₂ and NO. Besides this, the new solid base exhibits high activity in the removal of volatile nitrosamine N-nitrosopyrrolidine (NPYR), for the first time expanding the application of solid bases to environmental catalysis.

Active chemisorption sites in functionalized ionic liquids for carbon capture

Carbon capture with site-containing ionic liquids is reviewed with particular attention on the activation and design of the interaction sites.

Interface and core relaxation dynamics of IL molecules in nanopores of ordered mesoporous MCM-41: a dielectric spectroscopy study

The dynamics of ionic liquid molecules confined in ordered porous MCM-41 has been investigated by dielectric measurements and two types of confined states of IL were found; pore wall surface adsorbed IL and core of pore filled IL.

Polymeric ionic liquids for CO2 capture and separation: potential, progress and challenges

This review presents the potential of polymeric ionic liquids for CO₂ capture whose sorption efficiency surpasses that of molecular ionic liquids.

Fabricating a novel porous releaser of heparin

Reduced graphene oxide (rGO) could adsorb heparin of 112 mg g⁻¹ and released 80% of them within 30 days.