New reduction mechanism of CO dimer by hydrogenation to C2H4 on a Cu(100) surface: theoretical insight into the kinetics of the elementary steps

RSC Advances ◽  
2015 ◽  
Vol 5 (117) ◽  
pp. 96281-96289 ◽  
Author(s):  
Lihui Ou ◽  
Wenqi Long ◽  
Yuandao Chen ◽  
Junling Jin
Keyword(s):  
Reaction Pathway ◽  
Mechanistic Study ◽  
Reduction Mechanism ◽  
Elementary Steps ◽  
Kinetics Of ◽  
Theoretical Insight ◽  
Insight Into

An alternative reaction pathway for the production of C2H4 through the OCCO* intermediate from CO dimerization is provided in this mechanistic study.

scholarly journals Ideas and perspectives: The same carbon behaves like different elements – an insight into position-specific isotope distributions

2020 ◽  
Vol 17 (19) ◽  
pp. 4785-4795 ◽  
Author(s):  
Yuyang He ◽  
Xiaobin Cao ◽  
Huiming Bao
Keyword(s):  
Isotope Fractionation ◽  
Reaction Pathway ◽  
Research Effort ◽  
Limited Information ◽  
Bond Forming ◽  
Kinetic Isotope ◽  
Open Debate ◽  
Isotope Distributions ◽  
Kinetics Of ◽  
Insight Into

Abstract. It is expected that information on the source, reaction pathway, and reaction kinetics of an organic compound can be obtained from its position-specific isotope compositions or intramolecular isotope distribution (Intra-ID). To retrieve the information, we could use its predicted equilibrium Intra-ID as a reference for understanding the observed Intra-IDs. Historically, observed, apparently close-to-equilibrium carbon Intra-ID has prompted an open debate on the nature of biosystems and specifically the pervasiveness of reversible biochemical reactions. Much of the debate remains unresolved, and the discussion has not clearly distinguished between two states of equilibrium: (1) the equilibrium among the corresponding bond-breaking and bond-forming positions in reactant and product and (2) the equilibrium among all carbon positions within a compound. For an organic molecule with multiple carbon positions, equilibrium carbon Intra-ID can be attained only when a specific reaction is in equilibrium and the sources of each position are also in equilibrium with each other. An observed Intra-ID provides limited information on if the sources and pathways are both unconstrained. Here, we elaborate on this insight using examples of the observed Intra-IDs of hydroxyl-bearing minerals, N2O, and acetic acid. Research effort aiming to calibrate position-specific equilibrium and kinetic isotope fractionation factors for defined processes will help to interpret observed Intra-IDs of a compound accurately and fully.

scholarly journals Ideas and perspectives: Same Carbon Different Elements – An Insight into Position-Specific Isotope Patterns Within a Single Compound

2020 ◽  
Author(s):  
Yuyang He ◽  
Xiaobin Cao ◽  
Huiming Bao
Keyword(s):  
Isotope Fractionation ◽  
Reaction Pathway ◽  
Research Effort ◽  
Bond Breaking ◽  
Limited Information ◽  
Kinetic Isotope ◽  
Open Debate ◽  
Single Compound ◽  
Kinetics Of ◽  
Insight Into

Abstract. It is expected that information on the source, reaction pathway, and kinetics of an organic compound can be obtained from its position-specific isotope compositions or intramolecular isotope distribution (Intra-ID). To retrieve the information, we could use its equilibrium Intra-ID as a reference for understanding the observed Intra-IDs. Historically, observed, apparently close-to-equilibrium carbon Intra-ID had prompted an open debate on the nature of biosystem and specifically the pervasiveness of reversible biochemical reactions. Much of the debates remain unresolved, and the discussion has not clearly distinguished two states of equilibrium: (1) the equilibrium among the bond-breaking/forming positions in reactant and product, and (2) the equilibrium among all carbon positions in a compound. For an organic molecule with multiple carbon positions, equilibrium carbon Intra-ID can be attained only when a specific reaction is in equilibrium and the sources of each position are also in equilibrium with each other. An Intra-ID provides limited information if the sources and pathways are both unconstrained. Here, we elaborate on this insight using examples of the Intra-IDs of hydroxyl-bearing minerals, N2O, and acetic acid. Research effort aiming at calibrating position-specific equilibrium and kinetic isotope fractionation factors for defined processes will help to interpret Intra-IDs of a compound accurately and fully.

Theoretical Insight into Single Rh Atom Anchored on N-Doped γ-Graphyne as Excellent Bifunctional Electrocatalyst for OER and ORR: Electronic Regulation of Graphite Nitrogen

Nanoscale ◽  
2021 ◽  
Author(s):  
Youcheng Qin ◽  
Miao Yang ◽  
Chaofang Deng ◽  
Wei Shen ◽  
Rongxing He ◽  
...  
Keyword(s):  
Transition Metals ◽  
High Performance ◽  
Reaction Rate ◽  
Bifunctional Electrocatalyst ◽  
Late Transition Metals ◽  
Thermodynamics And Kinetics ◽  
Late Transition ◽  
Kinetics Of ◽  
Theoretical Insight ◽  
Insight Into

Reducing overpotential and increasing reaction rate, which are respectively determined by thermodynamics and kinetics of electrocatalysis, are the key to high performance bifunctional electrocatalysts for OER/ORR. Herein, six late-transition metals...

scholarly journals Self-consistent kinetic model of nested electron- and ion-scale magnetic cavities in space plasmas

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Jing-Huan Li ◽  
Fan Yang ◽  
Xu-Zhi Zhou ◽  
Qiu-Gang Zong ◽  
Anton V. Artemyev ◽  
...  
Keyword(s):  
Kinetic Model ◽  
Energy Partition ◽  
Multi Scale ◽  
Self Organized ◽  
Laboratory Plasmas ◽  
Self Consistent ◽  
Scale Structures ◽  
Kinetics Of ◽  
Theoretical Insight ◽  
Insight Into

Abstract NASA’s Magnetospheric Multi-Scale (MMS) mission is designed to explore the proton- and electron-gyroscale kinetics of plasma turbulence where the bulk of particle acceleration and heating takes place. Understanding the nature of cross-scale structures ubiquitous as magnetic cavities is important to assess the energy partition, cascade and conversion in the plasma universe. Here, we present theoretical insight into magnetic cavities by deriving a self-consistent, kinetic theory of these coherent structures. By taking advantage of the multipoint measurements from the MMS constellation, we demonstrate that our kinetic model can utilize magnetic cavity observations by one MMS spacecraft to predict measurements from a second/third spacecraft. The methodology of “observe and predict” validates the theory we have derived, and confirms that nested magnetic cavities are self-organized plasma structures supported by trapped proton and electron populations in analogous to the classical theta-pinches in laboratory plasmas.

Theoretical insight into the CdS/FAPbI3 heterostructure: a promising visible-light absorber

2021 ◽  
Author(s):  
Junli Chang ◽  
Liping Jiang ◽  
Guangzhao Wang ◽  
Yuhong Huang ◽  
Hong Chen
Keyword(s):  
Optical Absorption ◽  
Visible Light ◽  
Visible Light Range ◽  
Light Absorber ◽  
Absorption Performance ◽  
Theoretical Insight ◽  
Insight Into

The optical absorption performance of the perovskite FAPbI3 in the visible-light range is significantly improved by constructing a CdS/FAPbI3 heterostructure.

scholarly journals Theoretical Insight into the Reversal of Chemoselectivity in Diels-Alder Reactions of α,β-Unsaturated Aldehydes and Ketones Catalyzed by Brønsted and Lewis Acids

Organics ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 38-49
Author(s):  
Lakhdar Benhamed ◽  
Sidi Mohamed Mekelleche ◽  
Wafaa Benchouk
Keyword(s):  
Lewis Acids ◽  
Major Product ◽  
Diels Alder ◽  
Unsaturated Ketone ◽  
Unsaturated Aldehydes ◽  
Aldehydes And Ketones ◽  
Theoretical Insight ◽  
Insight Into ◽  
Good Agreement

Experimentally, a reversal of chemoselectivity has been observed in catalyzed Diels–Alder reactions of α,β-unsaturated aldehydes (e.g., (2E)-but-2-enal) and ketones (e.g., 2-hexen-4-one) with cyclopentadiene. Indeed, using the triflimidic Brønsted acid Tf2NH as catalyst, the reaction gave a Diels–Alder adduct derived from α,β-unsaturated ketone as a major product. On the other hand, the use of tris(pentafluorophenyl)borane B(C6F5)3 bulky Lewis acid as catalyst gave mainly the cycloadduct of α,β-unsaturated aldehyde as a major product. Our aim in the present work is to put in evidence the role of the catalyst in the reversal of the chemoselectivity of the catalyzed Diels–Alder reactions of (2E)-but-2-enal and 2-Hexen-4-one with cyclopentadiene. The calculations were performed at the ωB97XD/6-311G(d,p) level of theory and the solvent effects of dichloromethane were taken into account using the PCM solvation model. The obtained results are in good agreement with experimental outcomes.

Mechanistic Study of Metal–Ligand Cooperativity in Mn(II)-Catalyzed Hydroborations: Hemilabile SNS Ligand Enables Metal Hydride-Free Reaction Pathway

ACS Catalysis ◽  
2021 ◽  
pp. 9043-9051
Author(s):  
Matthew R. Elsby ◽  
Mina Son ◽  
Changjin Oh ◽  
Jessica Martin ◽  
Mu-Hyun Baik ◽  
...  
Keyword(s):  
Metal Hydride ◽  
Reaction Pathway ◽  
Mechanistic Study ◽  
Sns Ligand ◽  
Metal Ligand
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