Single-platform carbon capture and conversion: how advanced metal-organic frameworks are unlocking next-generation solar refineries

As atmospheric carbon dioxide (CO₂) concentrations continue to rise—surpassing 427 ppm in 2024 and projected to reach up to 980 ppm by the end of the century—carbon capture and utilization (CCU) technologies have become pivotal in global efforts to achieve carbon neutrality. Traditional CCU approaches typically separate carbon capture and conversion into distinct, multi-step operations. This decoupled approach often incurs heavy energy penalties during thermal or chemical desorption and leads to interfacial mass-transfer losses as captured CO₂ migrates to separate catalytic sites.

To address these inefficiencies, a team of researchers from Jiangsu University of Science and Technology and Jiangsu University has published a comprehensive review in ENGINEERING Energy detailing the development of advanced Metal-Organic Frameworks (MOFs). These porous, highly crystalline materials are capable of acting as all-in-one platforms that integrate high-affinity CO₂ capture, localized microenvironment enrichment, and direct, in situ photocatalytic conversion into high-value chemical fuels under solar irradiation.

Integrated "Capture, Enrichment, and In Situ Conversion"

MOFs consist of secondary building units (SBUs) constructed from metal clusters coordinated with organic linkers. By precisely engineering these building blocks, researchers can tailor both the chemical affinity of the framework and its electronic band structure. In an integrated MOF-based CCU system, CO₂ molecules captured from flue gas or ambient air do not require energy-intensive desorption and long-distance phase migration. Instead, they are enriched locally within the uniform microporous channels and converted directly at adjacent or identical photocatalytic active sites into value-added compounds such as carbon monoxide (CO), formic acid (HCOOH), methanol (CH₃OH), and methane (CH₄).

Key Insights and Structural Strategies

The review systematically evaluates structural engineering strategies across both capture and conversion domains:

1. Tailoring CO₂ Capture Sites

• Open Metal Sites (OMSs): Thermally or chemically evacuating coordinated ligands exposes unsaturated Lewis acidic metal nodes with partial positive charges. Because CO₂ possesses a high quadrupole moment and polarizability, OMSs (such as those in Mg-MOF-74) achieve strong selective binding even under low partial pressures.
• Lewis Basic Sites (LBSs): Functionalizing organic linkers or metal nodes with amine groups (NH₂, alkylamines) or hydroxyl groups (‒OH) introduces chemisorption pathways. LBS-functionalized MOFs exhibit exceptional CO₂ selectivity at low partial pressures and demonstrate high moisture tolerance.
• Polar Functional Groups: Incorporating electronegative fluorine units (e.g., SiF₆^2-, NbOF₅^2-, fluorinated linkers) creates strong dipole-quadrupole interactions with CO₂. Combined with hydrophobic shielding, these frameworks enable energy-efficient, moisture-resistant CO₂ capture under ambient conditions.

2. Engineering Photocatalytic Performance

To overcome narrow light absorption and rapid electron-hole recombination, modern MOFs employ precise modification strategies:

• Band Gap Optimization: Incorporating electron-donating groups (‒NH₂, ‒OCH₃, ‒SH) on organic linkers elevates the valence band position, narrowing the band gap and expanding light harvesting into the visible-light spectrum.
• Charge Transfer & Active Site Construction: Constructing multivariate (MTV) frameworks, dual-metal nodes, defect sites, and heterojunctions (such as MOF/semiconductor, MOF/COF, or quantum dot composites) significantly accelerates charge separation and promotes multi-electron reduction pathways (C₁ and C₂+ product formation).

3. Overcoming Technical Challenges

Despite notable laboratory progress, the authors emphasize that translating integrated MOF-based CCU systems to real-world industrial deployment requires addressing key hurdles:

1. Matching the dynamic kinetic rates of fast physical/chemical adsorption with slower photocatalytic reduction steps.
2. Maintaining framework stability under humid or acidic flue gas conditions.
3. Developing continuous-flow solar reactors that maximize mass transport and light utilization.

Article Information & Links

· Journal: ENGINEERING Energy

· Read the full article for free: https://rdcu.be/d9QT9SM7SzQa

· Cite this article: Lin, S., Ning, C., Xiao, S., Cheng, W., Xie, Z., & Shi, W. (2026). Advanced MOFs-based materials as platforms for carbon dioxide capture and simultaneous photocatalytic conversion. ENGINEERING Energy, 20(5), 10770. https://doi.org/10.1007/s11708-026-1077-x

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