Article
Chemistry, Physical
Michael Fischer
Summary: This study used electronic structure calculations to investigate the adsorption of carbamazepine (CBZ) in eleven all-silica zeolites. It was found that zeolites with one-dimensional channels formed by twelve-membered rings exhibited the highest affinity towards CBZ. The fit of CBZ into the zeolite pores, maximizing dispersion interactions, was identified as the dominant factor determining the interaction strength. The calculations also contributed to the understanding of the atomic-level interaction between functional organic molecules and all-silica zeolites.
Article
Chemistry, Physical
Michal Fecik, Philipp N. Plessow, Felix Studt
Summary: The influence of confinement from eight different zeotypes on the formation of alkoxides from 13 primary alcohols was studied using dispersion corrected density functional theory calculations. It was found that van der Waals interactions between substrates and zeolite frameworks largely govern the variations in adsorption and transition state energies. Additionally, trends between different reactants are mainly due to the size of the molecules and can be quantitatively described by the number of atoms constituting them. Adsorbate stabilization was found to be largest for frameworks that are neither too small nor too spacious.
Article
Chemistry, Multidisciplinary
Yong Wu, Shanshan Cao, Iskander Douair, Laurent Maron, Xihe Bi
Summary: The [2+1] cycloaddition reaction of a metal carbene with an alkene often suffers from side reactions, leading to lower yields of cyclopropanation products. By adding a low concentration of diazo compound to alkenes, it was found that AgOTf catalysis can efficiently produce cyclopropane products from hindered alkenes.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Marin Puget, Viacheslav Shcherbakov, Sergey Denisov, Philippe Moreau, Jean-Pierre Dognon, Mehran Mostafavi, Sophie Le Caer
Summary: The nature of the primary species formed in FEC depends on the amount of FEC in the solution, which will affect its performance in the electrolyte.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Physical
Zhiyao Duan, Graeme Henkelman
Summary: This study uses global optimization and constant-potential density functional theory to simulate the complete process of Pt dissolution, revealing the formation and dissolution mechanism of a two-dimensional Pt surface oxide. The findings provide a fundamental understanding of Pt dissolution under potential cycling, which is essential for the rational design of durable Pt-based cathodes for fuel cells.
Article
Chemistry, Multidisciplinary
Raphael Robidas, Claude Y. Legault
Summary: A mechanism is proposed to explain the formation of benzobicyclo[3.2.0]heptane derivatives from 1,7-enyne derivatives bearing a terminal cyclopropane, which has been previously reported.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Engineering, Environmental
Nannan Wu, Mingzhu Liu, Bingru Tian, Zunyao Wang, Virender K. Sharma, Ruijuan Qu
Summary: In this study, the oxidation of five phenolic contaminants using ferrate(VI) was investigated to understand the reaction mechanisms. Experimental and theoretical calculations revealed that the reaction rate constants were correlated with the energy of the highest occupied molecular orbital. Electron-donating groups (-R) were found to be more easily oxidized by ferrate(VI) compared to weak electron withdrawing groups (-X) and strong electron-withdrawing groups (-(C=O)-). The dominance of Fe(VI) in the reaction process was determined, and four main reaction mechanisms, including single-oxygen transfer, double-oxygen transfer, ·OH attack, and electron-transfer-mediated coupling reaction, were proposed. Density functional theory calculations suggested that the presence of -(C=O)- facilitated the occurrence of double-oxygen transfer and ·OH attack reactions, while the tendency of single-oxygen transfer and electron-transfer reaction varied with different substituents. Furthermore, the double-oxygen transfer pathway was found to be a common reaction mechanism during the ferrate(VI) oxidation of phenolic compounds.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Chemistry, Physical
B. B. Xiao, L. Yang, H. Y. Liu, X. B. Jiang, B. Aleksandr, E. H. Song, Q. Jiang
Summary: The study systematically investigates the oxygen reduction reaction and oxygen evolution reaction of graphene materials embedded with TMN4 clusters (TM = Fe, Co, Ni) using density functional theory calculations. It demonstrates that the functionalization of graphene can dramatically alter the activity and stability of TMN4 clusters, offering new insights into the design of bifunctional oxygen electrodes.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Multidisciplinary
Michael Fischer, Carlos Bornes, Luis Mafra, Joao Rocha
Summary: ITQ-13 is a medium-pore zeolite that can be prepared in all-silica form and as silicogermanate with Si/Ge ratios as low as 3. The energetically most favourable Ge distributions for Si/Ge ratios between 55 and 6 have been investigated using dispersion-corrected density functional theory calculations, showing Ge atoms are incorporated at specific locations in the cages.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Physical
Guangtong Hai, Haihui Wang
Summary: Accurate prediction of catalytic performance based on DFT calculation is crucial for nitrogen fixation. However, current computational methods ignore the effects of electrode potential and solvation, resulting in large deviations between predicted and measured potentials. This study proposes an external iteration method and a hybrid solvent model to account for these effects, achieving good agreement between theoretical and experimental potentials. These findings have important implications for prediction of other electrocatalytic systems.
Article
Chemistry, Physical
Yu-Feng Ding, Shuang-Feng Yin, Meng-Qiu Cai
Summary: This study investigates the mechanisms of photocatalytic toluene selective oxidation reactions, as well as the influence of water on these reactions. The results show that the oxidation potential of the photocatalyst is crucial for efficient catalysis, and the dehydration reaction is the rate-determining step for converting toluene into benzaldehyde. Furthermore, water has a dual role in photocatalytic reactions.
Article
Chemistry, Physical
Kailai Lin, Patrick TomHon, Soren Lehmkuhl, Raul Laasner, Thomas Theis, Volker Blum
Summary: This study provides an in-depth theoretical analysis of key chemical equilibria in Signal Amplification by Reversible Exchange (SABRE) using density functional theory calculations and harmonic transition state theory. The research shows that under typical experimental conditions, the Gibbs free energies of the two key states involved in pyridine-hydrogen exchange are essentially the same, indicating optimality for SABRE. Additionally, a methanol-containing intermediate is proposed as a plausible transient species in the process.
Article
Chemistry, Physical
Mingming Luo, Chao Liu, Meiling Liu, Shaik Gouse Peera, Tongxiang Liang
Summary: This study systematically investigated the mechanism of CO oxidation on doped graphene catalysts through DFT calculations, finding that FeFe@C6, FeCo@C6, and FeNi@C6 are efficient for CO oxidation. Additionally, heteronuclear dimeric catalysts FeCo@C6 and FeNi@C6 exhibit better catalytic activity and lower energy barriers compared to homonuclear dimeric catalyst FeFe@C6.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Multidisciplinary
Yumin Yang, Shuang Feng, Jianan Su, Yutong Gong, Junjie Wang
Summary: The effects of modification strategies on the activation of nitrogen molecules and the electrocatalytic nitrogen reduction reaction (eNRR) were systematically studied. It was found that Mo(II)-Fe2(DOAnBDC) and Mo(II)-Fe2F2(BBTA) are potential high-performance eNRR electrocatalysts, with their activity related to the arrangement of molybdenum's d orbitals and charge transfer.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2022)
Article
Chemistry, Physical
Meena Rittiruam, Siriwimol Somdee, Puwit Buapin, Nuttanon Aumnongpho, Nuttapat Kerdprasit, Tinnakorn Saelee, Soorathep Kheawhom, Nutchapon Chotigkrai, Supareak Praserthdam, Piyasan Praserthdam
Summary: The study investigates the deactivation mechanisms of alpha-manganese dioxide electrocatalyst during charge-discharge cycling using density functional theory-based analysis, attributing the deactivation to phase transformation from alpha-MnO2 to beta-MnO2 and the formation of the limiting *OOH species during oxygen reduction reaction. It suggests that preventing phase transformation is crucial for high-performance MnO2-based electrocatalysts for ORR/OER.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)