Study of the structural and energetic properties of nanoligas formed by CeO2-ZrO2 via molecular dynamics calculations

• Grant number: 20/10532-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2020
• End date: October 31, 2022
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Juarez Lopes Ferreira da Silva
• Grantee: Mylena Novaes Santos
• Host Institution: Instituto de Química de São Carlos (IQSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Company: Universidade de São Paulo (USP). Instituto de Química de São Carlos (IQSC)
• Associated research grant: 17/11631-2 - CINE: computational materials design based on atomistic simulations, meso-scale, multi-physics, and artificial intelligence for energy applications, AP.PCPE

Abstract

In the face of global warming, intensified by the increase in the emission of CO2 from the burning of fossil fuels, there is an urgent search for ways to mitigate the emission of carbon dioxide, since climate change can be irreversible. Thus, as a promising approach for reducing emissions of CO2 and replacing the use of fossil fuels, there is the conversion of carbon dioxide into chemicals and fuels with high added value, such as methanol (CH3OH), which can be obtained through hydrogenation by heterogeneous catalysis in which different nanostructured materials are used. A nanoliga (a nanoparticle formed by more than one or two metals), can have specific properties enhanced or induced due to synergistic effects of the atoms in its structure. In addition, its application in catalysis is potentially promising compared to analogous bulks. In this way, the formation of a nanoliga Ce1-xZrxO2 results in an increase in the performance of the catalyst by promoting greater resistance to sintering, greater reducibility of the oxide and improving the capacity of oxygen storage. However, for nanoliga to achieve the best performance, an understanding of the correlation between the fractions of the ions Ce+4 and Zr+4, the chemical structure of material and the effects of temperature on its structural and energetic properties. Therefore, in this work, simulations of Molecular Dynamics (DM) with classical force fields (second-generation) implemented in the LAMMPS molecular dynamics simulation package will be carried out for the study of such properties of nanoparticles formed by binary mixtures of Ce1-xZrxO2, making it possible to obtain structural and physicochemical properties such as diffusivity and ionic conductivity. Different analysis techniques will be used as well as calculation of the transport properties of the atoms of the systems to obtain a complete understanding of the catalytic properties, which will be evaluated in terms of their electrostatic potentials, excess energies, etc.