The catalytic performance of multi-walled carbon nanotubes (MWCNTs) with different surface chemistry was studied in the decomposition reaction of H2O2 at various values of pH and temperature. A comparative analysis of experimental and quantum chemical calculation results is given. It has been shown that both the lowest calculated activation energy (∼18.9 kJ/mol) and the highest rate constant correspond to the N-containing CNT. The calculated chemisorption energy values correlate with the operation stability of MWCNTs. Based on the proposed quantum chemical model it was found that the catalytic activity of carbon materials in electron transfer reactions is controlled by their electron donor capability.
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http://dx.doi.org/10.1016/j.jcis.2014.09.045 | DOI Listing |
J Phys Chem B
January 2025
Department of Chemistry and Biochemistry, University of Arizona, 1306 East University Boulevard, Tucson, Arizona 85721, United States.
Natural enzymes are powerful catalysts, reducing the apparent activation energy for reactions and enabling chemistry to proceed as much as 10 times faster than the corresponding solution reaction. It has been suggested for some time that, in some cases, quantum tunneling can contribute to this rate enhancement by offering pathways through a barrier inaccessible to activated events. A central question of interest to both physical chemists and biochemists is the extent to which evolution introduces mechanisms below the barrier, or tunneling mechanisms.
View Article and Find Full Text PDFJ Comput Chem
January 2025
Institute of Soil Science and Soil Conservation, Research Centre for BioSystems, Land Use and Nutrition (iFZ), Justus Liebig University Giessen, Giessen, Germany.
Halogenated benzenes (HBs) are hydrophobic organic chemicals belonging to persistent organic pollutants. Owing to their persistence, they represent a serious problem in environmental contamination, specifically of soils and sediments. One of the most important physical processes determining the fate of HBs in soils is adsorption to main soil components such as soil organic matter and soil minerals.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu, 210094, China.
After cyclo-pentazolate anion, a 5/6 fused structure of N is constructed, and four novel nitrogen-rich ionic compounds are assembled on its basis. The results of the quantum calculations revealed an uneven distribution of electrons on cyclo-N , with significant charge density near the N5/N9 atoms and an ADCH charge of -0.425.
View Article and Find Full Text PDFJ Chem Inf Model
January 2025
Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States.
In the field of computational chemistry, predicting bond dissociation energies (BDEs) presents well-known challenges, particularly due to the multireference character of reactive systems. Many chemical reactions involve configurations where single-reference methods fall short, as the electronic structure can significantly change during bond breaking. As generating training data for partially broken bonds is a challenging task, even state-of-the-art reactive machine learning interatomic potentials (MLIPs) often fail to predict reliable BDEs and smooth dissociation curves.
View Article and Find Full Text PDFChem Biodivers
January 2025
Ordu University: Ordu Universitesi, Department of Chemistry, Cumhuriyet Mah., Ordu, TURKEY.
The concise synthesis of O-methyled-inositol derivative and conduritol derivatives was obtained starting from p-benzoquinone. Spectroscopic methods have been performed for characterization of new synthesized compounds. Cyclitols are useful molecules with anticancer, antibiotic, antinutrient and antileukemic activity.
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