Molecular dynamics investigation of the structural and energetic properties of CeO2–MOx (M = Gd, La, Ce, Zr) nanoparticles

Mendonça, João Paulo Almeida de; Lourenço, Tuanan C.; Freitas, Luis Paulo Mezzina; Santo, Anderson Aparecido Espirito; Feliciano, Gustavo Troiano; Silva, Juarez L. F. Da

doi:10.1039/d1ma00543j

Cited by 10 publications

(34 citation statements)

References 70 publications

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“…Therefore, MD calculations are appropriate when the objective of the simulation seeks to obtain trajectory data for visualizing atom motion and studying system changes, energy profiles to identify stable configurations and energy transitions, RMSD to measure position deviation over time, and RDF (radial distribution function) to analyze system structure and interactions . MD has been widely used in biochemistry and biophysics to study the responses of macromolecules to changes in their environment, − in medical applications, drug discovery, and design, in the characterization of nanoparticles, , and, relevant to this article, in environmental pollution studies to guide treatment technologies, materials development, and discovery of adsorption and degradation pollutant mechanisms. ,− …”

Section: Computational Chemistry Methodsmentioning

confidence: 99%

Computational Chemistry as Applied in Environmental Research: Opportunities and Challenges

Sandoval-Pauker,

Yin,

Castillo

et al. 2023

ACS EST Eng.

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The constant development of computer systems and infrastructure has allowed computational chemistry to become an important component of environmental chemistry research. In the past decade, the application of quantum and classical mechanical calculations to model and understand environmental systems has increased exponentially. In this review, we highlight various applications of computational chemistry techniques in areas of environmental chemistry research (e.g., wastewater/air treatment, sensing, biodegradation). We briefly describe each computational approach, starting with quantum chemistry principle methods followed by molecular mechanics (MM), molecular dynamics (MD), and hybrid QM/MM methods. The recent introduction of artificial intelligence and machine learning techniques and their potential to disrupt the field are also discussed. Challenges and current and future directions to address them are presented.

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Section: Computational Chemistry Methodsmentioning

confidence: 99%

Computational Chemistry as Applied in Environmental Research: Opportunities and Challenges

Sandoval-Pauker,

Yin,

Castillo

et al. 2023

ACS EST Eng.

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“…Here, we propose a theoretical framework to characterize the thermodynamic properties and the PES of finite-size particles . Our framework is based on three complementary steps, namely, generation of local and putative global minimum configurations for particles of finite-size, , evaluation of the thermodynamic properties via molecular dynamics simulations, and characterization of the PES via data mining analyses combined with dimensionality reduction. Figure shows the flowchart, which summarizes the framework and techniques used in each step.…”

Section: Theoretical Approach and Data Analysesmentioning

confidence: 99%

Theoretical Framework Based on Molecular Dynamics and Data Mining Analyses for the Study of Potential Energy Surfaces of Finite-Size Particles

Mendonça

Calderan

Lourenço

et al. 2022

J. Chem. Inf. Model.

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Nanoclusters are remarkably promising for the capture and activation of small molecules for fuel production or as precursors for other chemicals of high commercial value. Since this process occurs under a wide variety of experimental conditions, an improved atomistic understanding of the stability and phase transitions of these systems will be key to the development of successful technological applications. In this work, we proposed a theoretical framework to explore the potential energy surface and configuration space of nanoclusters to map the most important morphologies presented by those systems and the phase transitions between them. A fully automated process was developed, which combines global optimization techniques, classical molecular dynamics, and unsupervised machine learning algorithms. To showcase these capabilities of the approach, we explored the example of copper nanoclusters (Cu n ) where n = 13, 38, 55, 75, 98, 102, and 147. We not only reported a graphical potential energy surface for each size, but also explored the topology of the configuration space via structural and thermodynamic analyses. The effect of size on the potential energy surface and the critical temperature for solid−liquid phase transitions were also reported, highlighting the impact of magic numbers on those quantities.

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“…Experimentalmente, a presença de La é capaz de aumentar a estabilidade térmica do material, levando a maior resistência a sinterização. 31,32 Esses materiais são mais propensos a formarem a espécie ativa O 2 e que favorece a reação de acoplamento oxidativo do metano (OCM). 11 Devido aos resultados promissores com superfícies, nanoclusters e nanopartículas têm sido estudados.…”

Section: Revisão Da Literatura: óXidos De Lantânio E Cériounclassified

“…Nanoclusters baseados em CeO 2 têm atraído a atenção de pesquisadores de diversas áreas devido a suas interessantes figuras de mérito: abundância do cério, estabilidade térmica, superfície alcalina, estados de oxidação altamente reversíveis e energias de formação de vacâncias baixa. 15,32,35 Sendo assim, diversos estudos, experimentais [36][37][38][39][40] e teóricos, 31,[41][42][43][44] têm sido publicados para melhorar o entendimento das propriedades desses materiais na nanoescala. A principal dificuldade de aplicações práticas de nanoclusters é a sinterização que ocorre quando são submetidos a altas temperaturas, diminuindo a área superficial.…”

Section: Revisão Da Literatura: óXidos De Lantânio E Cériounclassified

“…Estudos teóricos demonstraram que abaixo da temperatura de transição de fase, a temperatura tem pouca influência na morfologia de nanopartículas, que por sua vez é mais influenciada pela composição. 31 Isso é válido para nanopartículas com algumas centenas de átomos, no entanto não existem ainda evidências sólidas para nanoclusters. Como discutido anteriormente, as vacâncias desempenham papel fundamental nesses materiais, sendo assim trabalhos teóricos sobre nanoclusters de céria revelaram que, ao aumentar o tamanho das partículas de céria, a energia de formação das vacâncias de oxigênio é reduzida.…”

Section: Problemas Em Aberto Na Escala Nanométricaunclassified

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Investigação teórica da distribuição de espécies químicas e formação de vacâncias de oxigênio em >i<nanoclusters>/i< de óxidos mistos La>sub<2>/sub<Ce>sub<2>/sub<O>sub<7>/su

Mocelim

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Nanoclusters of cerium oxides have applications in gas sensors, biomedicine, and catalysis of methane conversion reactions. The diverse applications are possible due to the redox capacity of cerium atoms with the formation of oxygen vacancies. The combination of two oxides modifies physical and chemical properties. Recent studies have shown that the addition of La to the structure of CeO 2 favors the formation of oxygen vacancies, which are essential to enhance the catalytic activities. Despite the advances made, our understanding is not yet satisfactory, particularly on the nano scale, where size effects are crucial. The objectives of this work are to investigate the distribution of chemical species as a function of temperature and the formation of vacancies in nanoclusters La 2 Ce 2 O 7 , CeO 2 , and La 2 O 3 , with 72 and 40 cations. The configurations were obtained via molecular dynamics (MD) and optimized through calculations based on density functional theory (DFT), using the exchange-correlation functional proposed by Perdew, Burke, and Ernzerhof, along with Hubbard corrections (PBE+U). Our data indicate that temperature influences the morphology and distribution of chemical species in the MD configurations. Our calculations of the radii of the nanoclusters and the effective coordination number (ECN) support this hypothesis, as the radii increase and the ECN decreases with temperature. The Ce 36 La 36 O 126 is an exception, with radii decreasing in regions close to the phase transition temperature (T c ). This is because this nanocluster exhibits cubic morphologies below the phase transition temperature (solid), and above the transition temperature (liquid), the configurations assume globular morphologies. For all nanoclusters, optimization reduces the influence of temperature on properties and eliminates voids in the configurations. The results of the ECN histograms show a diffuse distribution for the MD configurations, and after optimization, we observe a Gaussian distribution.

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Molecular dynamics investigation of the structural and energetic properties of CeO₂–MO_x (M = Gd, La, Ce, Zr) nanoparticles

Abstract: CeO2 -based materials have played a critical role in catalysis, where the substrate particles have reduced the size year by year due to experimental achievements in synthesis control. Thus, there...

Cited by 10 publications

References 70 publications

Computational Chemistry as Applied in Environmental Research: Opportunities and Challenges

Computational Chemistry as Applied in Environmental Research: Opportunities and Challenges

Theoretical Framework Based on Molecular Dynamics and Data Mining Analyses for the Study of Potential Energy Surfaces of Finite-Size Particles

Investigação teórica da distribuição de espécies químicas e formação de vacâncias de oxigênio em >i<nanoclusters>/i< de óxidos mistos La>sub<2>/sub<Ce>sub<2>/sub<O>sub<7>/su

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