Atomic Insights into the Melting Behavior of Metallic Nano-catalysts

Authors

  • Bahareh Mobedpour School of Metallurgical and Materials Engineering, College of Engineering, University of Tehran, Tehran, Iran
  • Reza Roumina School of Metallurgical and Materials Engineering, College of Engineering, University of Tehran, Tehran, Iran
  • Sina Rajabdoust School of Metallurgical and Materials Engineering, College of Engineering, University of Tehran, Tehran, Iran
Abstract:

In the present study, molecular dynamics simulations have been utilized to provide fundamental understanding of melting behavior of pure Pd and Pt nanoparticles with the size of 10 nm in diameter, both free and graphene-supported during continuous heating. The embedded atom method is employed to model the metal-metal interactions, whereas a Lennard-Jones potential is applied to describe the metal-carbon interactions. In addition, interactions between carbon atoms are defined by the adaptive intermolecular reactive bond order potential. Heating curves calculated between 298 K-2000 K are used to determine solid-liquid transitions. Based on simulation results, three approaches are used to investigate the thermal behavior of Pd and Pt nanoparticles. These include potential energy variation, the percentage of FCC atoms as a function of temperature and the mean square displacement method. Melting temperature of nanoparticles is found to decrease when the particles are supported by the graphene substrate. The decrease in melting temperature of particles is ascribed to the interaction of carbon atoms with nanoparticles. Structural changes during melting of nanoparticles are also detected through the common neighbor analysis and the mean square displacement method. The analyses of crystal structure shows that the supported nanoparticles melt from surface. In addition, a sharp increase in the mean square displacement of supported nanoparticles is observed after melting which is suggested to be responsible for the reduction of melting point of nanoparticles.

Upgrade to premium to download articles

Sign up to access the full text

Already have an account?login

similar resources

Insights into the effect of vanadium on chromium-vanadium Phillips catalysts for the ethylene polymerization

The chromium/vanadium bimetallic Phillips catalysts developed by our research group have been proved to be a promising process to produce bimodal polyethylene using a single-reactor process. The vanadium loading of CrV-1/1, CrV-1/2, and CrV-1/3 has a significant effect on the polymerization activity, product molecular weight (MW), as well as th...

full text

Atomic Resolution Characterization of Pt Based Bi-Metallic Nano-Catalysts Using Aberration Corrected STEM

The global energy shortage requires the substitute of new energy strategy and various type of new materials are investigated for energy conversion purpose, including thermoelectric, ferroelectric, superconductors, etc.[1,2]. Among them fuel cell batteries are of particular interest due to their high capacity, good stability and reliability. The oxygen reduction reaction (ORR) in the fuel cells ...

full text

Influence of Size on the Melting Temperature of Metallic Nanoparticle

   In This paper, the effect of size on melting temperature of metallic nanoparticles (Au, Pb and Bi) is theoretically simulated and explained. In this regard, the cause of difference in various experimental data is introduced, which is the difference between nanoparticles’ grain Gaussian distribution. This volume-depended model with the help of the Gaussian distribution can descri...

full text

Newer Insights into the Prsevention of the Common Cold

Since most colds are self-limiting, symptoms will usually resolve on their own in seven to ten days. For the majority of patients, treatment is symptomatic and targeted at the most bothersome symptoms. Specific nonprescription therapy may relieve cold symptoms but should be used with caution, especially in at-risk patient populations. Patients should monitor for worsening symptoms, and progress...

full text

Emerging insights into the biology of metastasis: A review article

Metastasis means the dissemination of the cancer cells from one organ to another which is not directly connected to the primary site. Metastasis has a crucial role in the prognosis of cancer patients. A few theories, different types of cell and several molecular pathways have been proposed to explain the mechanism of metastasis. In this work, the related articles in the limited period of time, ...

full text

My Resources

Save resource for easier access later

Save to my library Already added to my library

{@ msg_add @}


Journal title

volume 50  issue 2

pages  81- 89

publication date 2017-12-01

By following a journal you will be notified via email when a new issue of this journal is published.

Hosted on Doprax cloud platform doprax.com

copyright © 2015-2023