scholarly journals Reducing the irreducible: Dispersed metal atoms facilitate reduction of irreducible oxides.

2021 ◽  
Author(s):  
Ville Korpelin ◽  
Marko M. Melander ◽  
Karoliina Honkala
Keyword(s):  
Metal Atom ◽  
Single Atom ◽  
Strong Interactions ◽  
Theoretical Understanding ◽  
Precise Control ◽  
Orbital Interactions ◽  
Metal Atoms ◽  
Catalytically Active ◽  
Reducible Oxides

Oxide reducibility is a central concept quantifying the role of the support in catalysis. While reducible oxides are often considered catalytically active, irreducible oxides are seen as inert supports. Enhancing the reducibility of irreducible oxides has, however, emerged as an effective way to increase their catalytic activity while retaining their inherent thermal stability. In this work, we focus on the prospect of using single metal atoms to increase the reducibility of a prototypical irreducible oxide, zirconia. Based on extensive self-consistent DFT+U calculations, we demonstrate that single metal atoms significantly improve and tune the surface reducibility of zirconia. Detailed analysis of the observed single atom induced reducibility allows us to attribute the enhanced reducibility to strong interactions between the metal atom and the electrons trapped in the vacancy, and d-p orbital interactions between the metal atom and oxygen. This analysis enables transferring the obtained theoretical understanding to other irreducible oxides as well. The detailed understanding of how oxide reducibility can be tuned offers precise control over the catalytic properties of metal--oxides.

scholarly journals Role of Chemical Structure of Support in Enhancing the Catalytic Activity of a Single Atom Catalyst Toward NRR: A Computational Study

2021 ◽  
Vol 9 ◽  
Author(s):  
Thillai Govindaraja Senthamaraikannan ◽  
Selvaraj Kaliaperumal ◽  
Sailaja Krishnamurty
Keyword(s):  
Metal Atom ◽  
Density Functional ◽  
Computational Study ◽  
Molecular Nitrogen ◽  
Red Shift ◽  
Single Atom ◽  
Metal Atoms ◽  
Doped Graphene ◽  
Adsorption Energies

Using the periodic density functional theory–based methodology, we propose a potential catalytic system for dinitrogen activation, viz., single metal atoms (Mo, Fe, and V) supported on graphene-based sheets. Graphene-based sheets show an excellent potential toward the anchoring of single atoms on them (Mo, Fe, and V) with adsorption energies ranging between 1.048 and 10.893 eV. Factors such as defects and BN doping are noted to enhance the adsorption energies of single metal atoms on the support. The adsorption of a dinitrogen molecule on metal atom–anchored graphene-based supports is seen to be highly favorable, ranging between 0.620 and 2.278 eV. The adsorption is driven through a direct hybridization between the d orbitals of the metal atom (Mo, Fe, and V) on the support and the p orbital of the molecular nitrogen. Noticeably, BN-doped graphene supporting a single metal atom (Mo, Fe, and V) activates the N2 molecule with a red shift in the N–N stretching frequency (1,597 cm−1 as compared to 2,330 cm−1 in the free N2 molecule). This red shift is corroborated by an increase in the N–N bond length (1.23 Å from 1.09 Å) and charge transfer to an N2 molecule from the catalyst.

First-principles screening of single transition metal atoms anchored on two-dimensional C9N4 for the nitrogen reduction reaction

2021 ◽  
Vol 23 (14) ◽  
pp. 8784-8791
Author(s):  
Qingling Meng ◽  
Ling Zhang ◽  
Jinge Wu ◽  
Shuwei Zhai ◽  
Xiamin Hao ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Transition Metal ◽  
First Principles ◽  
Reduction Reaction ◽  
Single Atom ◽  
Two Dimensional ◽  
Metal Atoms ◽  
Transition Metal Atoms ◽  
Catalytically Active ◽  
Single Transition

Theoretical screening of transition metal atoms anchored on monolayer C9N4 as highly stable, catalytically active and selective single-atom catalysts for nitrogen fixation.

Pd1/BN as a promising single atom catalyst of CO oxidation: a dispersion-corrected density functional theory study

RSC Advances ◽  
2015 ◽  
Vol 5 (103) ◽  
pp. 84381-84388 ◽  
Author(s):  
Zhansheng Lu ◽  
Peng Lv ◽  
Jie Xue ◽  
Huanhuan Wang ◽  
Yizhe Wang ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Co Oxidation ◽  
Metal Atom ◽  
Density Functional ◽  
Single Atom ◽  
Two Dimensional ◽  
Density Functional Theory Study ◽  
Functional Theory ◽  
Metal Atoms ◽  
Two Dimensional Materials

Single metal atom catalysts exhibit extraordinary activity in a large number of reactions, and some two-dimensional materials (such as graphene and h-BN) are found to be prominent supports to stabilize single metal atoms.

Single Metal Atom Anchored on CN monolayer as an Excellent Electrocatalyst for the Nitrogen Reduction Reaction

2021 ◽  
Author(s):  
Zhaoqin Chu ◽  
Xuxin Kang ◽  
Xiangmei Duan
Keyword(s):  
Metal Atom ◽  
First Principles ◽  
Reduction Reaction ◽  
Single Atom ◽  
First Principles Calculations ◽  
Nitrogen Reduction ◽  
Metal Atoms

Based on the first-principles calculations, we have studied the behavior of single-atom catalysts formed by a series of single metal atoms (From Ti to Cu) and CN monolayer in nitrogen...

scholarly journals Potential Energy Surfaces for Reactions of X Metal Atoms (X = Cu, Zn, Cd, Ga, Al, Au, or Hg) with YH4 Molecules (Y = C, Si, or Ge) and Transition Probabilities at Avoided Crossings in Some Cases

2012 ◽  
Vol 2012 ◽  
pp. 1-17 ◽  
Author(s):  
Octavio Novaro ◽  
María del Alba Pacheco-Blas ◽  
Juan Horacio Pacheco-Sánchez
Keyword(s):  
Excited State ◽  
Excited States ◽  
Metal Atom ◽  
Potential Energy Surfaces ◽  
Transition Probabilities ◽  
Metal Atoms ◽  
Avoided Crossings ◽  
Reaction Barriers ◽  
Energy Surfaces

We review ab initio studies based on quantum mechanics on the most important mechanisms of reaction leading to the C–H, Si–H, and Ge–H bond breaking of methane, silane, and germane, respectively, by a metal atom in the lowest states in symmetry: X(2nd excited state, 1st excited state and ground state) + YH4 H3XYH H + XYH3 and XH + YH3. with X = Au, Zn, Cd, Hg, Al, and G, and Y = C, Si, and Ge. Important issues considered here are (a) the role that the occupation of the d-, s-, or p-shells of the metal atom plays in the interactions with a methane or silane or germane molecule, (b) the role of either singlet or doublet excited states of metals on the reaction barriers, and (c) the role of transition probabilities for different families of reacting metals with these gases, using the H–X–Y angle as a reaction coordinate. The breaking of the Y–H bond of YH4 is useful in the production of amorphous hydrogenated films, necessary in several fields of industry.

On the role of metal atom doping in hematite for improved photoelectrochemical properties: a comparison study

RSC Advances ◽  
2016 ◽  
Vol 6 (104) ◽  
pp. 101745-101751 ◽  
Author(s):  
Jinzhan Su ◽  
Jian Wang ◽  
Cong Liu ◽  
Bo Feng ◽  
Yubin Chen ◽  
...  
Keyword(s):  
Metal Atom ◽  
Photoelectrochemical Properties ◽  
Comparison Study ◽  
Systematic Comparison ◽  
Metal Atoms ◽  
Element Doping ◽  
Metal Element

A systematic comparison study of various metal atoms doped hematites was performed to look into the effect of metal element doping on the photoelectrochemical (PEC) properties of hematite photoelectrodes.

Influence of social networks on business processes’ development

2020 ◽  
Vol 19 (12) ◽  
pp. 2225-2252
Author(s):  
E.V. Popov ◽  
V.L. Simonova ◽  
O.V. Komarova ◽  
S.S. Kaigorodova
Keyword(s):  
Social Networks ◽  
Social Media ◽  
Business Models ◽  
Business Processes ◽  
Digital Economy ◽  
Theoretical Understanding ◽  
Sales Channels ◽  
A Value ◽  
The Impact

Subject. The emergence of new ways of interaction between sellers and buyers, the formation of new sales channels and product promotion based on the use of digital economy tools is at the heart of improving the business processes. Social networks became a tool for development; their rapid growth necessitates theoretical understanding and identification of potential application in enterprise's business process digitalization. Objectives. We explore the role of social media in the digitalization of business processes, systematize the impact of social networks on business processes of enterprises in the digital economy. Methods. The theoretical and methodological analysis of social networks as a tool for digitalization of company's business processes rests on the content analysis of domestic and foreign scientific studies, comparison, generalization and systematization. Results. We highlight the key effects of the impact of social networks on the business processes of the company; show that the digitalization of business processes should be considered in the context of a value-based approach, aimed at creating a value through the algorithmization of company operations. We determine that social networks are one of the most important tools for digitalization of company's business processes, as they have a high organizational and management potential. We also systematize the effects of social media on company's business processes. Conclusions. We present theoretical provisions of the impact of social networks on business processes of enterprises, which will enable to model and organize ideas about the development of digital ecosystems and the formation of business models.

SUSTAINABLE LIVELIHOOD THROUGH SKILL DEVELOPMENT AMONG RURAL YOUTH: ROLE OF MICRO-FINANCE IN THE DEVELOPMENTAL PARADIGM

2017 ◽  
Vol 14 (1) ◽  
pp. 156-173
Author(s):  
Vikram Singh
Keyword(s):  
Social Interactions ◽  
Skill Development ◽  
Well Being ◽  
Rural Youth ◽  
Inclusive Development ◽  
Sustainable Livelihood ◽  
Theoretical Understanding ◽  
Societal Structure ◽  
Policy Shifts

This  article  attempts to  analyse  the  process  of  sustainable  livelihood  through skill development and its conceptual and theoretical understanding in India with reference to rural youth. In India skill development is demanded for economic growth and inclusive development; hence the rural population cannot be overlooked. Employable skills alone have not been able to generate sufficient employment among rural youth or address/promote well-being and sustainable livelihood. Various frameworks associated with skill development leave scope for reforms to strengthen the implementation of various policy shifts in respect of rural development and government/non-government organisations. The process of skill development for rural youth through the establishment of institutions, launch of policy/programmes and their linkages with micro-finance are considered, as the distinctive nature and features of micro-finance in relation to the forces of societal structure, social relationships, and social interactions leading towards collective interests and norms that shape the lives of rural youth. Lastly, analysis is done and conclusions drawn on the basis of discussion.

Sewage sludge as a precursor of adsorbents/catalysts for environmental applications

2007 ◽  
Vol 2 (1) ◽  
Author(s):  
A. Ros ◽  
C. Canals-Batlle ◽  
M.A. Lillo-Ródenas ◽  
E. Fuente ◽  
M. A. Montes-Morán ◽  
...  
Keyword(s):  
Sewage Sludge ◽  
Room Temperature ◽  
Waste Water Treatment ◽  
Textural Properties ◽  
Active Species ◽  
Elemental Sulphur ◽  
Gaseous Emissions ◽  
Removal Experiments ◽  
Catalytically Active

This paper focuses on the valorisation of solid residues obtained from the thermal treatment of sewage sludge. In particular, sewage sludge samples were collected from two waste water treatment plants (WWTPs) with different sludge line basic operations. After drying, sludges were heated up to 700 °C in appropriate ovens under diluted air (gasification) and inert (pyrolysis) atmospheres. The solids obtained, as well as the dried (raw) sludges, were characterised to determine their textural properties and chemical composition, including the speciation of their inorganic fraction. All the materials under study were employed as adsorbents/catalysts in H2S removal experiments at room temperature. It was found that, depending on the particular sludge characteristics, outstanding results can be achieved both in terms of retention capacities and selectivity. Some of the solids outperform commercially available sorbents specially designed for gaseous emissions control. In these adsorbents/catalysts, H2S is selectively oxidised to elemental sulphur most likely due to the presence of inorganic, catalytically active species. The role of the carbon-enriched part on these solids is also remarked.

Promotion of Sustainable Livelihood through Skill Development Among Rural Youth - Role of Micro-Finance in Developmental Paradigm

2016 ◽  
Vol 4 (1) ◽  
Author(s):  
Vikram Singh
Keyword(s):  
Skill Development ◽  
Well Being ◽  
Rural Youth ◽  
Inclusive Development ◽  
Sustainable Livelihood ◽  
Theoretical Understanding ◽  
Government Organizations ◽  
Policy Shift ◽  
Development Paradigm

The present paper attempts to analyze the process of sustainable livelihood through skill development and its conceptual and theoretical understanding in India with reference to rural youth. In India skill development is demanded for economic growth and inclusive development, hence rural population cannot be overlooked. It also tries to highlight that employable skills alone have not been able to sufficiently generate employment among rural youth despite it wont address/promote the well-being process and sustainable livelihood. It is also based on the assumption that various frameworks associated with skill development leave scope for reforms as the gaps prevails that weaken implementation addressed by various policy shift in rural development paradigm and government/non-government organizations. The paper also aspires to look into the process of skill development towards rural youth through establishments of institutions, launch of policy/programmes and their linkages with micro-finance. It also look into the distinctive nature/features of micro-finance against the dominant forces of societal structure, social relationships, social interactions leading towards collective interests and norms that shape the quality and quantity of lives of individuals. Lastly analysis and conclusion have been made on the basis of discussion.

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