A Japanese natural mordenite was modified by acid washing as well as cation-exchange. Crystal structure, porosity, and active sites of the modified natural mordenites were characterized, and their CO2 adsorptivity were examined. Contraction as well as expansion of the mordenitic unit cell in the natural zeolite and distortion of zeolite structure by acid washing are plausibly shown by XRD. Long-term washing by nitric acid induces enlargement of micropore volume, increasing the micropore dimension but decreasing the large pore dimension over the mesoporous range. The degree of dehydration has an important role in CO2 adsorption. Metal ionic sites affect both the irreversible CO2 adsorption and the CO2 equilibrium adsorption at low concentration. Li+ ion-exchange brings about a great CO2 adsorption but reduces the CO2-surface interaction due to molecular size effect. Ca2+ ion-exchange has its main effect in the enhancement of CO2 desorption energy. Copyright 1997 Academic Press. Copyright 1997Academic Press
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http://dx.doi.org/10.1006/jcis.1997.5079 | DOI Listing |
Sci Total Environ
January 2025
Program in Environmental and Polymer Engineering, Graduate School of INHA University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea; Department of Environmental Engineering, INHA University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea. Electronic address:
The increasing CO concentration in the atmosphere has substantial impacts on the global temperature. For energy sustainability and minimization of the effects of global warming, an approach to understand CO capturing and a carbon neutral culture is extremely essential in the present circumstances. The CO emission from vehicles and industries can be minimized using energy cost-effective techniques and can be converted more selectively into reusable fuels via thermochemical, electrochemical, photochemical, photocatalytic, electrocatalytic, biological and inorganic carbonate-based approaches.
View Article and Find Full Text PDFNat Commun
January 2025
Beijing Key Laboratory for Science and Application of Functional Molecular and Crystalline Materials, Department of Chemistry and Chemical Engineering, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing, China.
Artificial photosynthesis of urea from NH and CO seems to remain still essentially unexplored. Herein, three isomorphic three-dimensional covalent organic frameworks with twofold interpenetrated ffc topology are functionalized by benzene, pyrazine, and tetrazine active moieties, respectively. A series of experiment results disclose the gradually enhanced conductivity, light-harvesting capacity, photogenerated carrier separation efficiency, and co-adsorption capacity towards NH and CO in the order of benzene-, pyrazine-, and tetrazine-containing framework.
View Article and Find Full Text PDFMetal-organic framework materials exhibit significant potential for diverse applications in gas adsorption and separation. We have studied the performance changes of Cu-BTC, Cu-MBTC and Cu-EBTC under different water-containing conditions. GCMC studies shows that, compared with Cu-BTC, the water absorption properties of Cu-MBTC and Cu-EBTC have a certain degree of decline, which is consistent with the experimental results.
View Article and Find Full Text PDFInorg Chem
January 2025
Frontiers Science Center for New Organic Matter, Key Laboratory of Advanced Energy Materials Chemistry (MOE), College of Chemistry, Nankai University, Tianjin 300071, China.
The fixation of carbon dioxide (CO) directly from flue gas into valuable chemicals like 2-oxazolidinones is of great significance for economic and environmental benefits, which is typically catalyzed by noble-metal catalysts and under harsh conditions. Herein, a novel 2-fold interpenetrated framework {[Co(μ-O)(TCA)(HDPTA)]·2HO·2DMF} [Co(II)-based metal-organic framework ()] containing [Co] clusters and highly dense amino groups (-NH) dispersed in the channel was prepared, exhibiting high solvent/pH stability and CO adsorption capacity (24.9 cm·g).
View Article and Find Full Text PDFChem Sci
January 2025
J. Mike Walker '66 Department of Mechanical Engineering, Texas A&M University College Station TX 77843 USA
This perspective work examines the current advancements in integrated CO capture and electrochemical conversion technologies, comparing the emerging methods of (1) electrochemical reactive capture (eRCC) though amine- and (bi)carbonate-mediated processes and (2) direct (flue gas) adsorptive capture and conversion (ACC) with the conventional approach of sequential carbon capture and conversion (SCCC). We initially identified and discussed a range of cell-level technological bottlenecks inherent to eRCC and ACC including, but not limited to, mass transport limitations of reactive species, limitation of dimerization, impurity effects, inadequate generation of CO to sustain industrially relevant current densities, and catalyst instabilities with respect to some eRCC electrolytes, amongst others. We followed this with stepwise perspectives on whether these are considered intrinsic challenges of the technologies - otherwise recommendations were disclosed where appropriate.
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