Hydroxy-substituted aromatic N-heterocycles as high-affinity CO2 adsorbents: a DFT study.
Puthiyavalappil K Arathi1,2, Cherumuttathu H Suresh1,2,3
1Chemical Sciences and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram, 695019, India. sureshch@gmail.com.
Physical Chemistry Chemical Physics : PCCP
|June 27, 2025
Summary
Hydroxy-substituted aromatic N-heterocycles show promise for CO2 capture. Anionic forms and cation stabilization significantly enhance adsorption, offering new avenues for CO2 sequestration materials.
Area of Science:
- Computational Chemistry
- Materials Science
- Environmental Science
Background:
- Pioneering work demonstrated CO2 capture in pyridine-containing ionic liquids.
- Exploration of N-heterocycles as CO2 adsorbents is an active research area.
Purpose of the Study:
- Investigate hydroxy-substituted aromatic N-heterocycles for CO2 adsorption.
- Determine the impact of structural modifications on CO2 capture capacity.
- Explore mechanisms of CO2 interaction and potential for conversion.
Main Methods:
- Density Functional Theory (DFT) calculations.
- Molecular Electrostatic Potential (MESP) analysis.
- Modeling of solvent effects using monoethanolamine (MEA).
Main Results:
- CO2 adsorption capacity increases with nitrogen centers and hydroxy groups.
- Anionic N-heterocycles exhibit enhanced CO2 adsorption via covalent bonding.
- Cations (Li+, P(CH3)4+) stabilize CO2 adsorption, improving interaction energies.
- Solvent effects show modest impact on neutral/anionic systems, enhanced affinity in ion-paired systems.
- Enol-keto transformations for CO2 conversion are energetically unfavorable.
Conclusions:
- Hydroxy-substituted N-heterocycles, especially anionic and cation-stabilized forms, are promising for CO2 capture.
- Findings provide guidelines for designing advanced CO2 sequestration materials.
- Highlights potential for experimental validation and real-world applications.
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