Insertion of CO2 in metal ion-doped two-dimensional covalent organic frameworks.

Carbon capture is one of the essential low-carbon technologies required to achieve societal climate goals at the lowest cost. Covalent organic frameworks (COFs) are promising adsorbents for CO2 capture because of their well-defined porosity, large surface area, and high stability. Current COF-based CO2 capture is mainly based on a physisorption mechanism, exhibiting smooth and reversible sorption isotherms. In the present study, we report unusual CO2 sorption isotherms featuring one or more tunable hysteresis steps with metal ion (Fe3+, Cr3+, or In3+)-doped Schiff-base two-dimensional (2D) COFs (Py-1P, Py-TT, and Py-Py) as adsorbents. Synchrotron X-ray diffraction, spectroscopic and computational studies indicate that the sharp adsorption steps in the isotherm originate from the insertion of CO2 between the metal ion and the N atom of the imine bond on the inner pore surface of the COFs as the CO2 pressure reaches threshold values. As a result, the CO2 adsorption capacity of the ion-doped Py-1P COF is increased by 89.5% compared with that of the undoped Py-1P COF. This CO2 sorption mechanism provides an efficient and straightforward approach to enhancing the CO2 capture capacity of COF-based adsorbents, yielding insights into developing chemistry for CO2 capture and conversion.

Unlocking the Potential of CO2 Capture: A Synergistic Hybridization Strategy for Polymeric Hydrogels with Tunable Physicochemical Properties.

Unlocking CO2 capture potential remains a complex and challenging endeavor. Here, a blueprint is crafted for optimizing materials through CO2 capture and developing a synergistic hybridization strategy that involves synthesizing CO2-responsive hydrogels by integrating polymeric networks interpenetrated with polyethyleneimine (PEI) chains and inorganic CaCl2. Diverging from conventional CO2 absorbents, which typically serve a singular function in CO2 capture, these hybrid PEAC hydrogels additionally harness its presence to tune their optical and mechanical properties once interacting with CO2. Such synergistic functions entail two significant steps: (i) rapid CO2-fixing through PEI chains to generate abundant carbamic acid and carbamate species and (ii) mineralization via CaCl2 to induce the formation of CaCO3 micro-crystals within the hydrogel matrix. Due to the reversible bonding, the PEAC hydrogels enable the decoupling of CO2 through an acid fumigation treatment or a heating process, achieving dynamic CO2 capture-release cycles up to 8 times. Furthermore, the polyethyleneimine-acrylamide-calcium chloride (PEAC) hydrogel exhibits varying antibacterial attributes and high interfacial adhesive strength, which can be modulated by fine-tuning the compositions of PEI and CaCl2. This versatility underscores the promising potential of PEAC hydrogels, which not only unlocks CO2 capture capabilities but also offers opportunities in diverse biological and biomedical applications.

Flame-Resistant Inorganic Films by Self-Assembly of Clay Nanotubes and their Conversion to Geopolymer for CO2 Capture.

Self-assembling of very long natural clay nanotubes represents a powerful strategy to fabricate thermo-stable inorganic thin films suitable for environmental applications. In this work, self-standing films with variable thicknesses (from 60 to 300 µm) are prepared by the entanglement of 20-30 µm length Patch halloysite clay nanotubes (PT_Hal), which interconnect into fibrosus structures. The thickness of the films is crucial to confer specific properties like transparency, mechanical resistance, and water uptake. Despite its completely inorganic composition, the thickest nanoclay film possesses elasticity comparable with polymeric materials as evidenced by its Young's modulus (ca. 1710 MPa). All PT_Hal-based films are fire resistant and stable under high temperature conditions preventing flame propagation. After their direct flame exposure, produced films do not show neither deterioration effects nor macroscopic alterations. PT_Hal films are employed as precursors for the development of functional materials by alkaline activation and thermal treatment, which generate highly porous geopolymers or ceramics with a compact morphology. Due to its high porosity, geopolymer can be promising for CO2 capture. As compared to the corresponding inorganic film, the CO2 adsorption efficiency is doubled for the halloysite geopolymeric materials highlighting their potential use as a sorbent.

Fundamentals and Recent Progress in Magnetic Field Assisted CO2 Capture and Conversion.

CO2 capture and conversion technology are highly promising technologies that definitely play a part in the journey towards carbon neutrality. Releasing CO2 by mild stimulation and the development of high efficiency catalytic processes are urgently needed. The magnetic field, as a thermodynamic parameter independent of temperature and pressure, is vital in the enhancement of CO2 capture and conversion process. In this review, the recent progress of magnetic field-enhanced CO2 capture and conversion is comprehensively summarized. The theoretical fundamentals of magnetic field on CO2 adsorption, release and catalytic reduction process are discussed, including the magnetothermal, magnetohydrodynamic, spin selection, Lorentz forces, magnetoresistance and spin relaxation effects. Additionally, a thorough review of the current progress of the enhancement strategies of magnetic field coupled with a variety of fields (including thermal, electricity, and light) is summarized in the aspect of CO2 related process. Finally, the challenges and prospects associated with the utilization of magnetic field-assisted techniques in the construction of CO2 capture and conversion systems are proposed. This review offers a reference value for the future design of catalysts, mechanistic investigations, and practical implementation for magnetic field enhanced CO2 capture and conversion.

CO2 Uptake and Stability Enhancement in Vinyltrimethoxysilane-Treated SBA-15 Solid Amine-Based Sorbents.

Silica-supported amine absorbents, including materials produced by tethering aminosilanes or infusion of poly(ethyleneimine), represent a promising class of materials for CO2 capture applications, including direct air and point source capture. Various silica surface treatments and functionalization strategies are explored to enhance stability and CO2 uptake in amine-based solid sorbent systems. Here, the synthesis and characterization of novel vinyltrimethoxysilane-treated Santa Barbara Amorphous-15 (SBA-15) supports and the corresponding enhancement in CO2 uptake compared to various SBA-15-based control supports are presented. The relationship between CO2 diffusion and amine efficiency in these systems is explored using a previously reported kinetic model. The synthesized materials are characterized with CO2 and H2O isotherms, diffuse reflectance infrared Fourier transform spectroscopy, 1H T1-T2 relaxation correlation NMR, and rapid thermal cycling experiments. The novel support materials are shown to enable high amine efficiencies, approaching a fourfold improvement over standard SBA-15-supported amines, while simultaneously exhibiting excellent stability when cycled rapidly under humid conditions. As the poly(ethyleneimine) loadings are held constant across the various samples, enhancements in CO2 uptake are attributed to differences in the way the poly(ethyleneimine) interacts with the support surface.

Self-Regenerative Ni-Doped CaTiO3/CaO for Integrated CO2 Capture and Dry Reforming of Methane.

In this work, a new type of multifunctional materials (MFMs) called self-regenerative Ni-doped CaTiO3/CaO is introduced for the integrated CO2 capture and dry reforming of methane (ICCDRM). These materials consist of a catalytically active Ni-doped CaTiO3 and a CO2 sorbent, CaO. The article proposes a concept where the Ni catalyst can be regenerated in situ, which is crucial for ICCDRM. Exsolved Ni nanoparticles are evenly distributed on the surface of CaTiO3 under H2 or CH4, and are re-dispersed back into the CaTiO3 lattice under CO2. The Ni-doped CaTiO3/CaO MFMs show stable CO2 capture capacity and syngas productivity for 30 cycles of ICCDRM. The presence of CaTiO3 between CaO grains prevents CaO/CaCO3 thermal sintering during carbonation and decarbonation. Moreover, the strong interaction of CaTiO3 with exsolved Ni mitigates severe accumulation of coke deposition. This concept can be useful for developing MFMs with improved properties that can advance integrated carbon capture and conversion.

High-Entropy Fluorite Oxide-Modified CaO-Based Sorbent Pellets for Enhanced High-Temperature CO2 Capture.

The calcium looping technology employing CaO-based sorbents is pivotal for capturing CO2 from flue gas. However, the intrinsic low thermodynamic stability of CaO-based sorbents and the requisite molding step induce severe sintering issues, diminishing their cyclic stability. Herein, a high-entropy fluorite oxide (HEFO) inert stabilizer premised on entropy stabilization and synergistic effect strategies is introduced. HEFO-modified, CaO-based sorbent pellets are synthesized via a rapid cigarette butt-assisted combustion process (15 min) combined with the graphite molding method. Post-multiple cycles, their CO2 capture capacity reaches 0.373 g g-1, which is 2.6-fold superior to that of pure CaO, demonstrating markedly enhanced anti-sintering properties. First, the subtle morphological and crystallographic modifications suggest that the inherent entropy stability of HEFO imparts robust thermal resistance. Concurrently, the disordered structure of single-phase HEFO exhibits a high affinity for CaO, resulting in an interface binding energy of -1.83 eV, in sharp contrast to the -0.112 eV of pure CaO, thereby restricting CaO migration. Additionally, the multi-element synergistic effect of HEFO reduces the energy barrier by 0.15 eV, leading to a 40% and 140% increase in carbonation and calcination rates, respectively. This work presents highly efficient and rapidly synthesized CaO-based sorbent pellets, showcasing promising potential for industrial application.

Efficient utilization of xylose requires CO2 fixation in Synechococcus elongatus PCC 7942.

Cyanobacteria show great promise as autotrophic hosts for the renewable biosynthesis of useful chemicals from CO2 and light. While they can efficiently fix CO2, cyanobacteria are generally outperformed by heterotrophic production hosts in terms of productivity and titer. Photomixotrophy, or co-utilization of sugars and CO2 as carbon feedstocks, has been implemented in cyanobacteria to greatly improve productivity and titers of several chemical products. We introduced xylose photomixotrophy to a 2,3-butanediol producing strain of Synechococcus elongatus PCC 7942 and characterized the effect of gene knockouts, changing pathway expression levels, and changing growth conditions on chemical production. Interestingly, 2,3-butanediol production was almost completely inhibited in the absence of added CO2. Untargeted metabolomics implied that RuBisCO was a significant bottleneck, especially at ambient CO2 levels, restricting the supply of lower glycolysis metabolites needed for 2,3-butanediol production. The dependence of the strain on elevated CO2 levels suggests some practical limitations on how xylose photomixotrophy can be efficiently carried out in S. elongatus.

Phenotypic and genomic characterization of Methanothermobacter wolfeii strain BSEL, a CO2-capturing archaeon with minimal nutrient requirements.

A new variant of Methanothermobacter wolfeii was isolated from an anaerobic digester using enrichment cultivation in anaerobic conditions. The new isolate was taxonomically identified via 16S rRNA gene sequencing and tagged as M. wolfeii BSEL. The whole genome of the new variant was sequenced and de novo assembled. Genomic variations between the BSEL strain and the type strain were discovered, suggesting evolutionary adaptations of the BSEL strain that conferred advantages while growing under a low concentration of nutrients. M. wolfeii BSEL displayed the highest specific growth rate ever reported for the wolfeii species (0.27 ± 0.03 h-1) using carbon dioxide (CO2) as unique carbon source and hydrogen (H2) as electron donor. M. wolfeii BSEL grew at this rate in an environment with ammonium (NH4+) as sole nitrogen source. The minerals content required to cultivate the BSEL strain was relatively low and resembled the ionic background of tap water without mineral supplements. Optimum growth rate for the new isolate was observed at 64°C and pH 8.3. In this work, it was shown that wastewater from a wastewater treatment facility can be used as a low-cost alternative medium to cultivate M. wolfeii BSEL. Continuous gas fermentation fed with a synthetic biogas mimic along with H2 in a bubble column bioreactor using M. wolfeii BSEL as biocatalyst resulted in a CO2 conversion efficiency of 97% and a final methane (CH4) titer of 98.5%v, demonstrating the ability of the new strain for upgrading biogas to renewable natural gas.IMPORTANCEAs a methanogenic archaeon, Methanothermobacter wolfeii uses CO2 as electron acceptor, producing CH4 as final product. The metabolism of M. wolfeii can be harnessed to capture CO2 from industrial emissions, besides producing a drop-in renewable biofuel to substitute fossil natural gas. If used as biocatalyst in new-generation CO2 sequestration processes, M. wolfeii has the potential to accelerate the decarbonization of the energy generation sector, which is the biggest contributor of CO2 emissions worldwide. Nonetheless, the development of CO2 sequestration archaeal-based biotechnology is still limited by an uncertainty in the requirements to cultivate methanogenic archaea and the unknown longevity of archaeal cultures. In this study, we report the adaptation, isolation, and phenotypic characterization of a novel variant of M. wolfeii, which is capable of maximum growth with minimal nutrients input. Our findings demonstrate the potential of this variant for the production of renewable natural gas, paving the way for the development of more efficient and sustainable CO2 sequestration processes.

MXene Synthesis and Carbon Capture Applications: Mini-Review.

MXenes, a class of two-dimensional transition metal carbides, nitrides, and carbonitrides, have garnered significant attention due to their remarkable potential for energy storage, electrocatalysis, and gas separation applications. The fabrication processes of MXene involve building up the MXene structure from constituent elements and the selective elimination of M-A bonds from the precursor MAX. However, considerable efforts are still required to design and develop efficient MXene-based technologies. This review article aims to briefly analyse the synthesis methods employed for MXene production, ranging from direct synthesis and conventional chemical wet etching approach to the more recent molten salt etching technique. The review highlights the advancements made in achieving precise control over the terminal groups, which is paramount for tailoring the properties of MXenes for specific applications. Furthermore, the potential of MXene-based materials for carbon capture applications, particularly in developing advanced adsorbents, is emphasized. The in-depth examination of MXene synthesis techniques and their implications for carbon capture applications provides a solid foundation for developing and optimizing these promising materials.

Solvent-Regulated Formation of Metal/Metal-Oxo Nodes in Two Indium Metal-Organic Frameworks: Syntheses, Structures, Selective Gas Adsorption and Fluorescence Sensor Properties.

Two water-stable indium metal-organic frameworks, (NH2Me2)3[In3(BTB)4] ⋅ 12DMA ⋅ 4.5H2O (In-MOF-1) and (NH2Me2)9[In9O6(BTB)8(H2O)4(DMSO)4] ⋅ 27DMSO ⋅ 21H2O (In-MOF-2) (BTB=4,4',4''-benzene-1,3,5-tribenzoate) with 3D interpenetrated structure has been constructed by regulating solvents. Structure analysis revealed that In-MOF-1 has a three-dimensional (3D) structure with a single metal core, while In-MOF-2 features an octahedron cage constructed by three kinds of metal clusters to further form a 3D structure. The fluorescence investigations showed that In-MOF-1 and In-MOF-2 are potential MOF-based fluorescent sensors to detect acetone and Fe3+ ions in EtOH or water with high sensitivity, excellent selectivity, recyclability and a low limit of detection. Moreover, the fluorescence mechanisms of In-MOF-1 and In-MOF-2 toward acetone and Fe3+ ions were further explained. In addition, In-MOF-2 has higher thermal and framework stability than In-MOF-1. The activated In-MOF-2 presents a high BET surface area of 998.82 m2g-1 and a pore size distribution of 8 to 16 Å. At the same time, In-MOF-2 exhibits high selective CO2 adsorption for CO2/CH4 and CO2/N2, respectively. Furthermore, the adsorption sites and adsorption isotherms were predicted using grand canonical Monte Carlo (GCMC) simulations, and the adsorption energy of the lowest-energy adsorption configuration was calculated using molecular dynamics (MD) simulations.

N-doped Porous Carbon Derived from the Pyrolysis of a Polydopamine-coated Hypercross-linked Polymer for Enhanced CO2 Adsorption.

Porous carbon materials can simultaneously capture and convert carbon dioxide, helping to reduce greenhouse gas emissions and using carbon dioxide as a feedstock for the production of valuable chemicals or fuel. In this work, a series of N-doped porous carbons (PDA@HCP(x:y)-T) was prepared; the CO2 adsorption capacity of the prepared PDA@HCP(x:y)-T was enhanced by coating polydopamine (PDA) on a hypercross-linked polymer (HCP) and then adjusting the mass ratio of PDA to HCP and the carbonization temperature. The results showed that the prepared PDA@HCP(1:1)-850 exhibited a high CO2 adsorption capacity due to abundant micropores (0.6762 cm3/g), a high specific surface area (1220.8 m²/g), and moderate surface nitrogen content (2.75%). Notably, PDA@HCP(1:1)-850 exhibited the highest CO2 uptake of 6.46 mmol/g at 0 °C and 101 kPa. Critically, these N-doped porous carbons can also be used as catalysts for the reaction of CO2 with epichlorohydrin to form chloropropylene carbonate, with chloropropylene carbonate yielding up to 64% and selectivity of the reaction reaching 94%. As a result, these N-doped porous carbons could serve as potential candidates for CO2 capture and conversion due to their high reactivity, excellent CO2 uptake, and good catalytic performance.

Reversible Capture Mechanism of CO2 as a Zn(II)-Methylcarbonate.

In this study, we elucidate the reaction mechanism for capturing CO2 with the ZnL1(MeOH) complex (L1=diacetyl-2-(4-methyl-3-thiosemicarbazone)-3-(2-hydrazinatopyridine)) in a methanol solution, using density functional theory calculations. One pathway involves the protonation of ZnL1(MeOH) by methylcarbonic acid, followed by ligand exchange of MeOH with MeOCO2 -. An alternative mechanism suggests a tautomerization between ZnL1(MeOH) and Zn(HL1)(OMe), followed by CO2 insertion. The latter pathway is energetically more favorable than the former and more complex than initially proposed. In fact, we unveiled that the solvent catalyzes tautomerization, as one explicit methanol molecule acts as a proton transfer agent. Then, Zn(HL1)(OMe) captures CO2, yielding a methylcarbonate bound to the metal center. The final step involves a rearrangement that leads to the cleavage of the Zn-O(Me)(COO) bond and the formation of a new Zn-O(COOMe) bond, along with the rotation of the methylcarbonate group. We consider an additional mechanism that combines tautomerization and ligand exchange but is endergonic and requires a high activation barrier for the ligand exchange. Furthermore, we evaluate the ligand basicity through the pKa calculated values of the Zn(II) complexes, the effects of varying the ligand from 4-methyl-thiosemicarbazone to 4-ethyl (L2), 4-phenethyl (L3), and 4-benzyl (L4) derivatives, and reversibility of the reaction in an argon environment.

Computational Study of Carbon Dioxide Capture by Tertiary Amines.

The reaction mechanisms and corresponding structure-activity relationships of tertiary amines with respect to CO2 capture have been investigated using density functional theory (DFT) calculations. The reaction mechanism for CO2 capture via base-catalyzed hydration to form bicarbonate is proposed to proceed in a single step involving proton transfer and the formation of a carbon-oxygen bond. Based on the height of the reaction barriers, we suggest that amines containing side chains with the ethyl group, along with a single hydroxyl group, and cyclic structures, are especially active for CO2 capture. The activation barrier is shown to be a descriptor for predicting the experimental CO2 loading values. To enhance the prediction accuracy for CO2 loading, we employ the sure-independence screening and sparsifying operator (SISSO) method, which can scan a large pool of mathematical terms stemming from combining DFT-derived descriptors to select the superior ones. Thus, we can predict the CO2 loading with acceptable accuracy from the obtained mathematical expression. Since the computational workload of applying this expression is negligible, this facilitates high-throughput screening and accelerates the design of tertiary amines for CO2 capture.

Cerium-MOF-Derived Composite Hierarchical Catalyst Enables Energy-Efficient and Green Amine Regeneration for CO2 Capture.

The excessive energy consumed restricts the application of traditional postcombustion CO2 capture technology and limits the achievement of carbon-neutrality goals. Catalytic-rich CO2 amine regeneration has the potential to accelerate proton transfer and increase the energy efficiency in the CO2 separation process. Herein, we reported a Ce-metal-organic framework (MOF)-derived composite catalyst named HZ-Ni@UiO-66 with a hierarchical structure, which can increase the CO2 desorbed amount by 57.7% and decrease the relative heat duty by 36.5% in comparison with the noncatalytic monoethanolamine (MEA) regeneration process. The composite catalyst of the CeO2 coating from the UiO-66 precursor on the HZ-Ni carrier shows excellent stability with a long lifespan. The HZ-Ni@UiO-66 catalyst also shows a universal catalytic effect in typical blended amine systems with a large cyclic capacity. The HZ-Ni@UiO-66 catalyst effectively decreases the energy barrier of the CO2 desorption reaction to reduce the time required to reach thermodynamics, consequently saving the energy consumption generated by water evaporation. This research provides a new avenue for advancing amine regeneration with less heat duty at low temperatures.

Zero-Emission Cement Plants with Advanced Amine-Based CO2 Capture.

Decarbonization of the cement sector is essentially required to achieve carbon neutrality to combat climate change. Amine-based CO2 capture is a leading and practical technology to deeply remove CO2 from the cement industry, owing to its high retrofittability to existing cement plants and extensive engineering experience in industrial flue gas decarbonization. While research efforts have been made to achieve low-carbon cement with 90% CO2 removal, a net-zero-emission cement plant that will be required for a carbon neutrality society has not yet been investigated. The present study proposed an advanced amine-based CO2 capture system integrated with a cement plant to achieve net-zero CO2 emission by pushing the CO2 capture efficiency to 99.7%. Monoethanomaine (MEA) and piperazine/2-amino-2-methyl-1-propanol (PZ-AMP) amine systems, which are considered to be the first- and second-generation capture agents, respectively, were detailed investigated to deeply decarbonize the cement plant. Compared to MEA, the advanced PZ-AMP system exhibited excellent energy performance with a regeneration duty of ∼2.6 GJ/tonne CO2 at 99.7% capture, 39% lower than the MEA process. This enabled a low CO2 avoided cost of $72.0/tonne CO2, which was 18% lower than that of the MEA-based zero-emission process and even 16.2% lower than the standard 90% MEA process. Sensitivity analysis revealed that the zero-emission capture cost of the PZ-AMP system would be further reduced to below $56/tonne CO2 at a $4/GJ steam production cost, indicating its economic competitiveness among various CO2 capture technologies to achieve a zero-emission cement plant.

Design Insights for Industrial CO2 Capture, Transport, and Storage Systems.

We present methods and insights for the design of CO2 capture, transport, and storage systems for industrial facilities with a case study focus on Louisiana. Our analytical framework includes (1) evaluating the scale and concentration of capturable CO2 emissions at individual facilities for the purpose of estimating the cost of CO2 capture retrofits that utilize various energy supply sources to meet parasitic demands; (2) screening to identify potential CO2 storage sites and estimate their capacities, injectivities, and costs; and (3) designing cost-minimized trucking or pipeline infrastructure connecting CO2 capture plants with storage sites, considering existing land uses, demographics, and a variety of social and environmental justice factors. Estimated levelized costs of capture at Louisiana's 190 industrial facilities range from below $50/tCO2 to above $500/tCO2, depending on facility-specific features. We identified 98 potential storage sites with storage costs ranging from $8 to $17/tCO2. We find that in most situations, pipelines are the least-costly mode of CO2 transport. When industrial facilities in a region share pipelines, aggregate pipeline mileage and average transport costs are dramatically lower than without sharing. Shared pipeline networks designed to avoid disadvantaged communities require right-of-way areas compared to those for networks that transect such communities, but result in 25% higher average per-tonne transport cost.

Life Cycle Greenhouse Gas Emissions of CO2-Enabled Sedimentary Basin Geothermal.

The expansion of renewable energy and the large-scale deployment of carbon dioxide (CO2) capture and storage (CCS) can decarbonize the power sector. The use of CO2 to extract geothermal heat from naturally porous and permeable sedimentary basins to generate electricity (CO2-plume geothermal (CPG) system) presents an opportunity to simultaneously generate renewable energy and geologically store CO2. In this study, we estimate the life cycle greenhouse gas (GHG) impacts of CPG systems through 12 scenarios in which CPG systems are combined with one of six CO2 sources (e.g., bioenergy with carbon capture and storage (BECCS) and iron and steel facilities) and operate in two geological settings. We find the life cycle GHG emissions of CPG systems ranging from -0.25 to -6.18 kg CO2eq/kWh. CPG systems can achieve the highest emissions reductions when utilizing the CO2 captured from BECCS. We evaluate uncertainty through a Monte Carlo simulation, demonstrating consistent net reductions in life cycle emissions and a local, one-parameter-at-a-time sensitivity analysis that identifies the CO2 capture capacity as the high-impact parameter of the results. Through the production of electricity, CPG systems can provide additional environmental benefits to the deployment of large-scale CCS.

Sulfur Migration Enhanced Proton-Coupled Electron Transfer for Efficient CO2 Desorption with Core-Shelled C@Mn3O4.

Transforming hazardous species into active sites by ingenious material design was a promising and positive strategy to improve catalytic reactions in industrial applications. To synergistically address the issue of sluggish CO2 desorption kinetics and SO2-poisoning solvent of amine scrubbing, we propose a novel method for preparing a high-performance core-shell C@Mn3O4 catalyst for heterogeneous sulfur migration and in situ reconstruction to active -SO3H groups, and thus inducing an enhanced proton-coupled electron transfer (PCET) effect for CO2 desorption. As anticipated, the rate of CO2 desorption increases significantly, by 255%, when SO2 is introduced. On a bench scale, dynamic CO2 capture experiments reveal that the catalytic regeneration heat duty of SO2-poisoned solvent experiences a 32% reduction compared to the blank case, while the durability of the catalyst is confirmed. Thus, the enhanced PCET of C@Mn3O4, facilitated by sulfur migration and simultaneous transformation, effectively improves the SO2 resistance and regeneration efficiency of amine solvents, providing a novel route for pursuing cost-effective CO2 capture with an amine solvent.

Solid Electrolytes for Low-Temperature Carbon Dioxide Valorization: A Review.

One of the most promising approaches to address the global challenge of climate change is electrochemical carbon capture and utilization. Solid electrolytes can play a crucial role in establishing a chemical-free pathway for the electrochemical capture of CO2. Furthermore, they can be applied in electrocatalytic CO2 reduction reactions (CO2RR) to increase carbon utilization, produce high-purity liquid chemicals, and advance hybrid electro-biosystems. This review article begins by covering the fundamentals and processes of electrochemical CO2 capture, emphasizing the advantages of utilizing solid electrolytes. Additionally, it highlights recent advancements in the use of the solid polymer electrolyte or solid electrolyte layer for the CO2RR with multiple functions. The review also explores avenues for future research to fully harness the potential of solid electrolytes, including the integration of CO2 capture and the CO2RR and performance assessment under realistic conditions. Finally, this review discusses future opportunities and challenges, aiming to contribute to the establishment of a green and sustainable society through electrochemical CO2 valorization.