Article
Chemistry, Multidisciplinary
A. Albinati, M. Grellier, J. Ollivier, P. A. Georgiev
Summary: In this study, high resolution inelastic neutron scattering techniques were used to investigate the microscopic dynamics of dihydrogen molecules in the RuH2(H-2)(2)[P(C5H9)(3))](2) complex with a high-hydrogen content. The study observed the quantum tunneling spectrum of the ground ortho-para hydrogen states at low temperatures and the corresponding quasi-elastic scattering due to rapid proton exchange at slightly elevated and near ambient temperatures. The energetics of the hydrides and possible reaction paths for proton exchange were also modeled using hybrid density functional theory calculations.
NEW JOURNAL OF CHEMISTRY
(2022)
Article
Biochemistry & Molecular Biology
Franz J. Giessibl
Summary: The nature of the chemical bond is crucial in various natural sciences, and the AFM technology allows for the study of individual chemical bonds. Experimental AFM data covers a range of chemical bonds, while density functional theory calculations are related to these studies. Frequency modulation AFM is a precise method that has enabled high precision measurements of bonding strengths.
Article
Chemistry, Multidisciplinary
Claudia E. Berdugo-Diaz, Melissa T. Manetsch, Yang Sik Yun, Jieun Lee, Jing Luo, Xue Chen, David W. Flaherty
Summary: Esters can be reduced to ethers and alcohols through C-O bond cleavage by hydrogenation and hydrogenolysis pathways on Bronsted acidic faujasite (M-FAU) supported metal nanoparticles. The rates and selectivities of each pathway are influenced by the metal identity (M=Co, Ni, Cu, Ru, Rh, Pd, and Pt). Pt-FAU catalyst exhibits propyl acetate consumption rates up to 100 times higher than other M-FAU catalysts and achieves a 34% selectivity for ethyl propyl ether. The reduction of esters appears to involve a bifunctional mechanism, with stepwise addition of H* atoms to the carbonyl to form hemiacetals on the metal sites, followed by hemiacetal diffusion to Bronsted acid sites for dehydration to ethers or decomposition to alcohol and aldehyde. The reduction rates of propyl acetate seem to be determined by H* addition to the carbonyl and C-O cleavage of hemiacetal.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Prerna Paliwal, Nabanita Deb, Daniel M. Reich, Ad van der Avoird, Christiane P. Koch, Edvardas Narevicius
Summary: Scattering resonances play a central role in collision processes, providing intuitive understanding of collision dynamics. Resonances localized in the reaction region lead to sharp peaks in reaction rates, while those outside the reaction region mainly modify elastic scattering.
Article
Chemistry, Physical
Diana L. Reese, Ryan P. Steele
Summary: In this study, ab initio molecular dynamics computer simulations were used to assess the motion and isomerization of dihydrogen/dihydride moieties in Mo(PH3)(5)H-2. The results showed that ligand rotations were dominant at low temperature and the classical thermodynamic distribution did not allow for the formation of dihydride forms. Surprisingly, simulations at higher temperatures revealed new tri-hydride isomers that were energetically competitive with the existing dihydride isomers.
JOURNAL OF PHYSICAL CHEMISTRY A
(2022)
Article
Chemistry, Physical
Jia-Xing Guo, Shao-Yi Wu, Si-Ying Zhong, Gao-Jun Zhang, Xing-Yuan Yu, Li-Na Wu
Summary: This study systematically investigates the adsorption behaviors of transition-metal atoms and toxic gas molecules on Janus MoSSe monolayer, revealing the impact of different atoms and molecules on the electronic structure and gas adsorption properties. The potential for CO catalytic oxidation on the Fe-MoSSe monolayer is discussed, showing a highly exothermic two-step route mechanism. The adsorption of TM atoms on Janus MoSSe monolayer may greatly enhance gas sensing performance and catalytic performance of CO oxidation.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
L. Craco
Summary: We investigate the electronic state of a two-dimensional Rashba square lattice proximitized to a square monolayer s-wave superconductor, analyzing the impact of dynamical electron-electron interactions. The interplay between electron-electron interactions and spin-orbit interactions, along with proximity-induced electron pairing, offers a universally applicable mechanism for designing Majorana fermions in 2D superconducting structures. The Rashba spin-orbit coupling drives channel differentiation, impacting the reconstructed superconducting state.
Article
Multidisciplinary Sciences
Xiao Zhang, Mengtao Zhang, Yuchen Deng, Mingquan Xu, Luca Artiglia, Wen Wen, Rui Gao, Bingbing Chen, Siyu Yao, Xiaochen Zhang, Mi Peng, Jie Yan, Aowen Li, Zheng Jiang, Xingyu Gao, Sufeng Cao, Ce Yang, A. Jeremy Kropf, Jinan Shi, Jinglin Xie, Mingshu Bi, Jeroen A. van Bokhoven, Yong-Wang Li, Xiaodong Wen, Maria Flytzani-Stephanopoulos, Chuan Shi, Wu Zhou, Ding Ma
Summary: The study demonstrates that Pt1 and Ptn stabilized on α-MoC surface can catalyze the WGS reaction at low temperatures, preventing catalyst deactivation due to oxidation and showing high stability with a high metal-normalized turnover number.
Article
Chemistry, Physical
Pablo Lozano-Reis, Hector Prats, Ramon Sayos, Jose A. Rodriguez, Francesc Illas
Summary: In this study, the adsorption and dissociation of CO2 and H-2 on Ni-n clusters supported on TiC(001) were examined using density functional theory calculations. The results showed that the Ni-n/TiC system exhibited stronger adsorption energies and lower dissociation energy barriers for CO2 and H-2 compared to the bare Ni(111) and TiC(001) surfaces. Additionally, it was found that two-dimensional supported clusters had stronger adsorption energies and lower CO2 dissociation energy barriers compared to three-dimensional supported clusters.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Physical
Zhun Hu, Tao Zhang, Dan Li, Ralph T. Yang
Summary: The effects of adding 3d transition metal oxides to Pd/TiO2 catalysts on the selective catalytic reduction of NO were investigated. Fe and Co additions showed promotional effects, while Cu addition had a negative impact.
CATALYSIS SCIENCE & TECHNOLOGY
(2021)
Article
Geochemistry & Geophysics
I Lindeman, M. Hansen, D. Scholz, S. F. M. Breitenbach, A. Hartland
Summary: This study highlights the potential of using first row transition metals as proxies for climate reconstructions in speleothems. The availability of these metals in speleothems is restricted by organic complexation, which affects their concentrations and isotope ratios in calcite. Through cave-analogue experiments, it was found that the presence of organic ligands can significantly influence the partitioning of transition metals into calcite, suggesting a novel and potentially quantitative paleohydrological proxy.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2022)
Article
Engineering, Environmental
Bin Su, Zhenmin Luo, Tao Wang, Chao Xie, Fangming Cheng
Summary: Using density functional theory and a detailed mechanism, the study explored the chemical kinetic behaviors of CH4/H-2/air mixture at the initial stage of explosion. Results show that the addition of H-2 accelerates the explosion reaction, but CH4 still plays a key role in the chain initiation stage.
JOURNAL OF HAZARDOUS MATERIALS
(2021)
Article
Engineering, Environmental
Bo-Jian Cao, Yi-Fei Sun, Hong-Nan Chen, Jin-Rong Zhong, Ming-Long Wang, Meng-Ya Niu, Jing-Yu Kan, Chang-Yu Sun, Dao-Yi Chen, Guang-Jin Chen
Summary: The combination of CO2/H2 injection and CH4 production with in situ steam reformation of CH4 offers a promising solution to green energy production and CO2 storage. However, the challenge lies in balancing CH4 recovery and CO2 storage. This study explores changing the composition of the injected gas at different stages to achieve high CO2 sequestration and CH4 recovery simultaneously, showing promising results in terms of CH4 recovery ratios, gas concentration, gas injection-production ratio, and H2 utilization efficiency. The approach proves to be economically viable and has potential for effective and safe exploitation of gas hydrate.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Physical
Erxun Han, Wei Fang, Michail Stamatakis, Jeremy O. Richardson, Ji Chen
Summary: It is commonly believed that it is unfavorable for adsorbed H atoms on carbonaceous surfaces to form H2 without the help of incident H atoms. However, recent quantum-mechanical simulations using ring-polymer instanton theory and ab initio electronic structure calculations reveal a qualitatively different picture. Deep tunnelling enables the recombination of adsorbed H atoms at low temperatures, with reaction rates enhanced by tens of orders of magnitude. Furthermore, a new path for H recombination via multidimensional tunnelling is identified. These findings emphasize the importance of hydrogen molecule formation at low temperatures in both experimental settings and natural environments.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Materials Science, Ceramics
Anand Gupta, Shikhar Nigam, Vijay M. Shinde
Summary: The gas-phase thermal decomposition of BCl3+CH4+H-2 mixtures, which is important for the chemical vapor deposition of boron carbide, was modeled using a detailed chemical kinetic mechanism. A reduced mechanism was derived from the detailed mechanism to facilitate reactor design.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2022)
