Atomic-level insights into the steric hindrance effect of single-atom Pd catalyst to boost the synthesis of dimethyl carbonate

2021 ◽  
pp. 120922
Author(s):  
Shufang Ji ◽  
Yuanjun Chen ◽  
Guofeng Zhao ◽  
Yu Wang ◽  
Wenming Sun ◽  
...  
Keyword(s):  
Steric Hindrance ◽  
Dimethyl Carbonate ◽  
Atomic Level ◽  
Single Atom ◽  
Pd Catalyst

scholarly journals Electronic metal–support interaction modulates single-atom platinum catalysis for hydrogen evolution reaction

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yi Shi ◽  
Zhi-Rui Ma ◽  
Yi-Ying Xiao ◽  
Yun-Chao Yin ◽  
Wen-Mao Huang ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Structure Activity Relationship ◽  
Atomic Level ◽  
Single Atom ◽  
Activity Relationship ◽  
Support Interaction ◽  
Structure Activity ◽  
Metal Support Interaction ◽  
Metal Support

AbstractTuning metal–support interaction has been considered as an effective approach to modulate the electronic structure and catalytic activity of supported metal catalysts. At the atomic level, the understanding of the structure–activity relationship still remains obscure in heterogeneous catalysis, such as the conversion of water (alkaline) or hydronium ions (acid) to hydrogen (hydrogen evolution reaction, HER). Here, we reveal that the fine control over the oxidation states of single-atom Pt catalysts through electronic metal–support interaction significantly modulates the catalytic activities in either acidic or alkaline HER. Combined with detailed spectroscopic and electrochemical characterizations, the structure–activity relationship is established by correlating the acidic/alkaline HER activity with the average oxidation state of single-atom Pt and the Pt–H/Pt–OH interaction. This study sheds light on the atomic-level mechanistic understanding of acidic and alkaline HER, and further provides guidelines for the rational design of high-performance single-atom catalysts.

scholarly journals Regulating coordination number in atomically dispersed Pt species on defect-rich graphene for n-butane dehydrogenation reaction

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xiaowen Chen ◽  
Mi Peng ◽  
Xiangbin Cai ◽  
Yunlei Chen ◽  
Zhimin Jia ◽  
...  
Keyword(s):  
Coordination Number ◽  
Density Functional ◽  
Activation Barrier ◽  
Density Functional Theory Calculation ◽  
Catalytic Performance ◽  
Atomic Level ◽  
Metal Nanoparticle ◽  
Single Atom ◽  
Nano Structure ◽  
Theory Calculation

AbstractMetal nanoparticle (NP), cluster and isolated metal atom (or single atom, SA) exhibit different catalytic performance in heterogeneous catalysis originating from their distinct nanostructures. To maximize atom efficiency and boost activity for catalysis, the construction of structure–performance relationship provides an effective way at the atomic level. Here, we successfully fabricate fully exposed Pt3 clusters on the defective nanodiamond@graphene (ND@G) by the assistance of atomically dispersed Sn promoters, and correlated the n-butane direct dehydrogenation (DDH) activity with the average coordination number (CN) of Pt-Pt bond in Pt NP, Pt3 cluster and Pt SA for fundamentally understanding structure (especially the sub-nano structure) effects on n-butane DDH reaction at the atomic level. The as-prepared fully exposed Pt3 cluster catalyst shows higher conversion (35.4%) and remarkable alkene selectivity (99.0%) for n-butane direct DDH reaction at 450 °C, compared to typical Pt NP and Pt SA catalysts supported on ND@G. Density functional theory calculation (DFT) reveal that the fully exposed Pt3 clusters possess favorable dehydrogenation activation barrier of n-butane and reasonable desorption barrier of butene in the DDH reaction.

scholarly journals Atomic engineering of single-atom nanozymes for enzyme-like catalysis

2020 ◽  
Vol 11 (36) ◽  
pp. 9741-9756 ◽  
Author(s):  
Weiwei Wu ◽  
Liang Huang ◽  
Erkang Wang ◽  
Shaojun Dong
Keyword(s):  
Atomic Level ◽  
Single Atom ◽  
Active Centers ◽  
Catalytic Activities ◽  
New Period ◽  
Atomic Engineering

Single-atom nanozymes with definite active centers, high catalytic activities and enzyme-like selectivities promote the nanozyme research entering a new period of atomic level.

Atomic-level active sites of efficient imidazolate framework-derived nickel catalysts for CO2 reduction

2019 ◽  
Vol 7 (46) ◽  
pp. 26231-26237 ◽  
Author(s):  
Fuping Pan ◽  
Hanguang Zhang ◽  
Zhenyu Liu ◽  
David Cullen ◽  
Kexi Liu ◽  
...  
Keyword(s):  
Active Sites ◽  
Co2 Reduction ◽  
Nickel Catalysts ◽  
Atomic Level ◽  
Single Atom ◽  
Dangling Bond

Active sites of single-atom nickel catalysts for CO2 reduction were revealed to be edge-located Ni–N2+2 sites with dangling bond-containing carbon atoms, which facilitate the dissociation of the C–O bond of *COOH intermediate.

scholarly journals Quantum Computation and Quantum Information by Michael E. Nielson and Isaac L. Chuang

2003 ◽  
Vol 1 (2) ◽  
pp. 120-121
Author(s):  
Neeraj Sinha
Keyword(s):  
Quantum Mechanics ◽  
Quantum Information ◽  
Quantum Computation ◽  
Semiconductor Industry ◽  
Atomic Level ◽  
Present Form ◽  
Single Atom ◽  
Large Size ◽  
Physical Laws ◽  
Ultimate Limit

One of the most promising scieniifc of East century was the Computers. Computers of initial days were of very large size consisting vacuum tubes ond valves. This has taken over by sernicor-,ductor and transistors which were 0' smaller size and more efficient. The rapid growth in the semiconductor industry hos led to the present form computer on our desktop. This hos initiated the questions about the ultimate limit of this development. AS size Of computer chip is decreasing, if has been predicted by Moor's law that within next twenty year, the size Of a sing bit will be of the order of a single atom. Physical laws governing the atomic phenomena, such cs quantum mechanics, are very different from macroscopic laws. so the computers operating on atomic level will not be Same cs pæsent days computers. This possibility has openee c completely new field of Quantum Computation.

Modeling of Steels and Steel Surfaces Using Quantum Mechanical First Principles Methods

2013 ◽  
Vol 762 ◽  
pp. 445-450
Author(s):  
Matti Alatalo ◽  
Heikki Pitkänen ◽  
Matti Ropo ◽  
Kalevi Kokko ◽  
Levente Vitos
Keyword(s):  
First Principles ◽  
Atomic Level ◽  
Single Atom ◽  
Quantum Mechanical ◽  
Bulk Alloy ◽  
Potential Approximation ◽  
Materials Modelling ◽  
Chemical Disorder ◽  
Steel Surfaces ◽  
Random Alloys

We describe recent progress in first principles materials modelling applied to iron alloys. First principles methods in general have proven to be an effective way of describing atomic level phenomena in solids. When applied to alloys with chemical disorder, however, the widely used supercell methods turn out to be impractical due to the vast variety of different possible configurations. This problem can be overcome using the coherent potential approximation (CPA), which enables the description of a multicomponent alloy in terms of an effective medium constructed in such a way that it represents, on the average, the scattering properties of the alloy. A bulk alloy, in the case of substitutional random alloys, can thus be described with a single atom while a slab is needed to describe surfaces. The exact muffin-tin orbitals (EMTO) method provides a first principles method that can be combined with the CPA in order to describe steels and other multicomponent alloys. We describe the EMTO-CPA method and provide examples of both bulk and surface properties that can be modelled with this method.

scholarly journals Broad and Comprehensive Approach to Evaluate Infrared Intensities at Atomic Level: The AC/DC Analysis

2020 ◽  
Author(s):  
Wagner Richter ◽  
Leonardo Duarte ◽  
Luciano N. Vidal ◽  
Roy E. Bruns
Keyword(s):  
Electronic Structure ◽  
Population Analysis ◽  
Atomic Level ◽  
Numerical Results ◽  
Comprehensive Approach ◽  
The Other ◽  
Single Atom ◽  
Infrared Intensity ◽  
Infrared Intensities ◽  
Automated Protocol

<div>We present a complete theoretical protocol to split infrared intensity in terms owing to individual atoms in two different but related approaches: the Atomic Contributions (AC's) how how the entire molecule motion is noticed by the electronic structure of a single atom, and therefore reflected on the intensity. On the other hand, the Dynamic Contributions (DC's) show how the displacement of a single atom is noticed by the electronic structure of the entire molecule, and reflected on the IR intensity. The two analyses are complementary ways of partitioning the same total intensity, and conserve most of the features of the total intensity itself. Combined they are called the AC/DC analysis. These can be further partitioned following the CCTDP (or CCT) models regarding the population analysis chosen by the researcher. The main conceptual features of the equations are highlighted and representative numerical results are shown to support the interpretation of the equations. The results are invariant to rotation and translation and can readily be extended to molecules of any size, shape or symmetry. A fully automated protocol managed by Placzek program is made available, free of charge.</div>

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