Surface restructuring of Cu-based single-atom alloy catalysts under reaction conditions: the essential role of adsorbates

2017 ◽  
Vol 19 (27) ◽  
pp. 18010-18017 ◽  
Author(s):  
Kunran Yang ◽  
Bo Yang
Keyword(s):  
Density Functional ◽  
Essential Role ◽  
Single Atom ◽  
Surface Restructuring ◽  
Reaction Conditions ◽  
Functional Theory ◽  
Alloy Catalysts ◽  
Single Atom Alloy ◽  
Catalytic Performances

The stabilities and catalytic performances of single-atom alloy (SAA) structures under the reaction conditions of acetylene hydrogenation are thoroughly examined utilizing density functional theory (DFT) calculations.

scholarly journals Selective Hydrogenation of Acetylene Catalysed by a B12N12 Cluster Doped with a Single Nickel Atom: A DFT Study

Catalysts ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 115 ◽  
Author(s):  
Yun Wang ◽  
Lihua Kang
Keyword(s):  
Selective Hydrogenation ◽  
Density Functional ◽  
Reaction Path ◽  
Nickel Atom ◽  
Single Atom ◽  
Functional Theory ◽  
Acetylene Hydrogenation ◽  
Selective Hydrogenation Of Acetylene ◽  
New Type ◽  
Catalytic Performances

To obtain a catalyst based on a non-precious metal that can replace traditional palladium-based selective catalysts of acetylene hydrogenation, the catalytic performances of two different configurations of a B12N12 cluster doped with a single nickel atom were studied by a density functional theory computational approach. After analysing the effect that the adsorption of reactants onto the clusters has on the reaction path, we determined the lowest energy path for the acetylene double hydrogenation. Comparing the acetylene hydrogenation activities and ethylene product selectivities of the B11N12Ni and B12N11Ni clusters, which have different doping sites, we determined the activities of these two catalysts to be similar to each other; however, the B11N12Ni cluster was calculated to have higher selectivity for ethylene as a product. This difference may be related to the moderate adsorption of hydrogen and acetylene on the B11N12Ni cluster. As a new type of nickel-based single-atom catalyst, B11N12Ni clusters may have research value in the selective hydrogenation of acetylene.

scholarly journals High-Throughput Screening Single-Atom Alloy for Electroreduction of Dinitrogen to Ammonia

2021 ◽  
Author(s):  
Guokui Zheng ◽  
Ziqi Tian ◽  
Xingwang Zhang ◽  
Liang Chen ◽  
Xu Qian ◽  
...  
Keyword(s):  
High Throughput Screening ◽  
Density Functional ◽  
Ammonia Synthesis ◽  
Density Functional Theory Calculations ◽  
Reduction Reaction ◽  
Single Atom ◽  
Functional Theory ◽  
Metal Doped ◽  
Single Atom Alloy ◽  
Single Atom Alloys

<p></p><p>Exploring electrocatalyst with high activity, selectivity and stability is essential for development of applicable electrocatalytic ammonia synthesis technology. By performing density functional theory calculations, we systematically investigated a series of transition-metal doped Au-based single atom alloys (SAAs) as promising electrocatalysts for nitrogen reduction reaction (NRR). For Au-based electrocatalyst, the first hydrogenation step (*N<sub>2</sub>→*NNH) normally determines the limiting potential of the overall reaction process. Compared with pristine Au(111) surface, introducing single atom can significantly enhance the binding strength of N<sub>2</sub>, leading to decreased energy barrier of the key step, i.e., ΔG(*N<sub>2</sub>→*NNH). According to simulation results, three descriptors were proposed to describe ΔG(*N<sub>2</sub>→*NNH), including ΔG(*NNH), <i>d</i>-band center, and . Eight doped elements (Ti, V, Nb, Ru, Ta, Os, W, and Mo) were initially screened out with limiting potential ranging from -0.75V to -0.30 V. Particularly, Mo- and W-doped systems possess the best activity with limiting potentials of -0.30 V, respectively. Then the intrinsic relationship between structure and the potential performance was further analyzed by using machine-learning. The selectivity, feasibility, stability of these candidates were also evaluated, confirming that SAA containing Mo, Ru ,Ta, and W could be outstanding NRR electrocatalysts. This work not only broadens the understating of SAA application in electrocatalysis, but also devotes to the discovery of novel NRR electrocatalysts.</p><br><p></p>

scholarly journals Single-atom alloy catalysts designed by first-principles calculations and artificial intelligence

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zhong-Kang Han ◽  
Debalaya Sarker ◽  
Runhai Ouyang ◽  
Aliaksei Mazheika ◽  
Yi Gao ◽  
...  
Keyword(s):  
Data Analytics ◽  
Density Functional ◽  
Simultaneous Optimization ◽  
Single Atom ◽  
Subgroup Discovery ◽  
First Principles Calculations ◽  
Reliable Prediction ◽  
Novel Approach ◽  
Alloy Catalysts ◽  
Single Atom Alloy

AbstractSingle-atom-alloy catalysts (SAACs) have recently become a frontier in catalysis research. Simultaneous optimization of reactants’ facile dissociation and a balanced strength of intermediates’ binding make them highly efficient catalysts for several industrially important reactions. However, discovery of new SAACs is hindered by lack of fast yet reliable prediction of catalytic properties of the large number of candidates. We address this problem by applying a compressed-sensing data-analytics approach parameterized with density-functional inputs. Besides consistently predicting efficiency of the experimentally studied SAACs, we identify more than 200 yet unreported promising candidates. Some of these candidates are more stable and efficient than the reported ones. We have also introduced a novel approach to a qualitative analysis of complex symbolic regression models based on the data-mining method subgroup discovery. Our study demonstrates the importance of data analytics for avoiding bias in catalysis design, and provides a recipe for finding best SAACs for various applications.

scholarly journals High-Throughput Screening Single-Atom Alloy for Electroreduction of Dinitrogen to Ammonia

2021 ◽  
Author(s):  
Guokui Zheng ◽  
Ziqi Tian ◽  
Xingwang Zhang ◽  
Liang Chen ◽  
Xu Qian ◽  
...  
Keyword(s):  
High Throughput Screening ◽  
Density Functional ◽  
Ammonia Synthesis ◽  
Density Functional Theory Calculations ◽  
Reduction Reaction ◽  
Single Atom ◽  
Functional Theory ◽  
Metal Doped ◽  
Single Atom Alloy ◽  
Single Atom Alloys

<p></p><p>Exploring electrocatalyst with high activity, selectivity and stability is essential for development of applicable electrocatalytic ammonia synthesis technology. By performing density functional theory calculations, we systematically investigated a series of transition-metal doped Au-based single atom alloys (SAAs) as promising electrocatalysts for nitrogen reduction reaction (NRR). For Au-based electrocatalyst, the first hydrogenation step (*N<sub>2</sub>→*NNH) normally determines the limiting potential of the overall reaction process. Compared with pristine Au(111) surface, introducing single atom can significantly enhance the binding strength of N<sub>2</sub>, leading to decreased energy barrier of the key step, i.e., ΔG(*N<sub>2</sub>→*NNH). According to simulation results, three descriptors were proposed to describe ΔG(*N<sub>2</sub>→*NNH), including ΔG(*NNH), <i>d</i>-band center, and . Eight doped elements (Ti, V, Nb, Ru, Ta, Os, W, and Mo) were initially screened out with limiting potential ranging from -0.75V to -0.30 V. Particularly, Mo- and W-doped systems possess the best activity with limiting potentials of -0.30 V, respectively. Then the intrinsic relationship between structure and the potential performance was further analyzed by using machine-learning. The selectivity, feasibility, stability of these candidates were also evaluated, confirming that SAA containing Mo, Ru ,Ta, and W could be outstanding NRR electrocatalysts. This work not only broadens the understating of SAA application in electrocatalysis, but also devotes to the discovery of novel NRR electrocatalysts.</p><br><p></p>

The Nature of S-N Bonding in Sulfonamides and Related Compounds: Insights into π-Bonding Contributions from Sulfur K-Edge XAS

2020 ◽  
Author(s):  
Tulin Okbinoglu ◽  
Pierre Kennepohl
Keyword(s):  
Density Functional ◽  
Chemical Properties ◽  
Functional Theory ◽  
Rotational Barriers ◽  
Td Dft ◽  
Nitrogen Bonds ◽  
X Ray Absorption ◽  
Related Compounds ◽  
And Chemical Properties

Molecules containing sulfur-nitrogen bonds, like sulfonamides, have long been of interest due to their many uses and chemical properties. Understanding the factors that cause sulfonamide reactivity is important, yet their continues to be controversy regarding the relevance of S-N π bonding in describing these species. In this paper, we use sulfur K-edge x-ray absorption spectroscopy (XAS) in conjunction with density functional theory (DFT) to explore the role of S<sub>3p</sub> contributions to π-bonding in sulfonamides, sulfinamides and sulfenamides. We explore the nature of electron distribution of the sulfur atom and its nearest neighbors and extend the scope to explore the effects on rotational barriers along the sulfur-nitrogen axis. The experimental XAS data together with TD-DFT calculations confirm that sulfonamides, and the other sulfinated amides in this series, have essentially no S-N π bonding involving S<sub>3p</sub> contributions and that electron repulsion and is the dominant force that affect rotational barriers.

γ-Valerolactone-Introduced Controlled-Isomerization of Glucose for Lactic Acid Production over Sn-Beta Catalyst

2021 ◽  
Author(s):  
Xinpeng Zhao ◽  
Zhimin Zhou ◽  
hu luo ◽  
Yanfei Zhang ◽  
Wang Liu ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Lactic Acid ◽  
Dft Calculations ◽  
Acid Production ◽  
Density Functional ◽  
Lactic Acid Production ◽  
Hydrothermal Conversion ◽  
Functional Theory ◽  
Environment Friendly

Combined experiments and density functional theory (DFT) calculations provided insights into the role of the environment-friendly γ-valerolactone (GVL) as a solvent in the hydrothermal conversion of glucose into lactic acid...

scholarly journals Role of Chemistry and Crystal Structure on the Electronic Defect States in Cs-Based Halide Perovskites

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1032
Author(s):  
Anirban Naskar ◽  
Rabi Khanal ◽  
Samrat Choudhury
Keyword(s):  
Crystal Structure ◽  
Density Functional ◽  
Covalent Bond ◽  
Density Functional Theory Calculations ◽  
Antisite Defect ◽  
Defect States ◽  
Functional Theory ◽  
Electronic Defect ◽  
Constituent Elements

The electronic structure of a series perovskites ABX3 (A = Cs; B = Ca, Sr, and Ba; X = F, Cl, Br, and I) in the presence and absence of antisite defect XB were systematically investigated based on density-functional-theory calculations. Both cubic and orthorhombic perovskites were considered. It was observed that for certain perovskite compositions and crystal structure, presence of antisite point defect leads to the formation of electronic defect state(s) within the band gap. We showed that both the type of electronic defect states and their individual energy level location within the bandgap can be predicted based on easily available intrinsic properties of the constituent elements, such as the bond-dissociation energy of the B–X and X–X bond, the X–X covalent bond length, and the atomic size of halide (X) as well as structural characteristic such as B–X–B bond angle. Overall, this work provides a science-based generic principle to design the electronic states within the band structure in Cs-based perovskites in presence of point defects such as antisite defect.

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