Redox behavior of a low-doped Pr-CeO 2 (111) surface. A DFT+U study

In this work, we investigated the redox behavior (donation and replenishing of oxygen) of a low praseodymium (Pr)-doped CeO 2 (111) surface. We considered a 3.7 at.% Pr doping and performed density functional calculations using the GGA formalism with the ‘U’ correction on Ce(4f) and Pr(4f) orbitals....

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Autores principales: Milberg, B., Juan, A., Irigoyen, B.
Formato: JOUR
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Acceso en línea:http://hdl.handle.net/20.500.12110/paper_01694332_v401_n_p206_Milberg
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spelling todo:paper_01694332_v401_n_p206_Milberg2023-10-03T15:07:09Z Redox behavior of a low-doped Pr-CeO 2 (111) surface. A DFT+U study Milberg, B. Juan, A. Irigoyen, B. DFT+U Dioxygen radicals Pr-doped CeO 2 Redox capacity Cerium oxide Doping (additives) Molecules Oxygen Oxygen vacancies Positive ions Anionic vacancies Catalytic performance Dft + u Dioxygens Doped CeO2 Excess electrons Molecular adsorption Redox capacity Praseodymium compounds In this work, we investigated the redox behavior (donation and replenishing of oxygen) of a low praseodymium (Pr)-doped CeO 2 (111) surface. We considered a 3.7 at.% Pr doping and performed density functional calculations using the GGA formalism with the ‘U’ correction on Ce(4f) and Pr(4f) orbitals. Our results indicate that Pr doping promotes oxygen donation by lowering the energy necessary to form surface anionic vacancies. When the Ce 0.963 Pr 0.037 O 2 (111) surface donates one oxygen, the two excess electrons locate on Pr and Ce cations and reduce them to Pr 3+ and Ce 3+ ones. Praseodymium doping also favors the activation of O 2 molecule on surface O-holes, leading to formation of a superoxide (O 2 − ) radical as well as to reoxidation of the Ce 3+ cation to Ce 4+ one. Additionally, we used the CO molecular adsorption for testing the reactivity of those superoxide species. The calculations expose the ability of these radicals to oxidize CO forming a CO 2 molecule floating on the surface. However, when the superoxide is in the immediate vicinity of Pr dopant a carbonate-type species is formed. Our theoretical results may help to gain insight into redox properties and improved catalytic performance of low-doped Pr-CeO 2 solids. © 2016 Elsevier B.V. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_01694332_v401_n_p206_Milberg
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic DFT+U
Dioxygen radicals
Pr-doped CeO 2
Redox capacity
Cerium oxide
Doping (additives)
Molecules
Oxygen
Oxygen vacancies
Positive ions
Anionic vacancies
Catalytic performance
Dft + u
Dioxygens
Doped CeO2
Excess electrons
Molecular adsorption
Redox capacity
Praseodymium compounds
spellingShingle DFT+U
Dioxygen radicals
Pr-doped CeO 2
Redox capacity
Cerium oxide
Doping (additives)
Molecules
Oxygen
Oxygen vacancies
Positive ions
Anionic vacancies
Catalytic performance
Dft + u
Dioxygens
Doped CeO2
Excess electrons
Molecular adsorption
Redox capacity
Praseodymium compounds
Milberg, B.
Juan, A.
Irigoyen, B.
Redox behavior of a low-doped Pr-CeO 2 (111) surface. A DFT+U study
topic_facet DFT+U
Dioxygen radicals
Pr-doped CeO 2
Redox capacity
Cerium oxide
Doping (additives)
Molecules
Oxygen
Oxygen vacancies
Positive ions
Anionic vacancies
Catalytic performance
Dft + u
Dioxygens
Doped CeO2
Excess electrons
Molecular adsorption
Redox capacity
Praseodymium compounds
description In this work, we investigated the redox behavior (donation and replenishing of oxygen) of a low praseodymium (Pr)-doped CeO 2 (111) surface. We considered a 3.7 at.% Pr doping and performed density functional calculations using the GGA formalism with the ‘U’ correction on Ce(4f) and Pr(4f) orbitals. Our results indicate that Pr doping promotes oxygen donation by lowering the energy necessary to form surface anionic vacancies. When the Ce 0.963 Pr 0.037 O 2 (111) surface donates one oxygen, the two excess electrons locate on Pr and Ce cations and reduce them to Pr 3+ and Ce 3+ ones. Praseodymium doping also favors the activation of O 2 molecule on surface O-holes, leading to formation of a superoxide (O 2 − ) radical as well as to reoxidation of the Ce 3+ cation to Ce 4+ one. Additionally, we used the CO molecular adsorption for testing the reactivity of those superoxide species. The calculations expose the ability of these radicals to oxidize CO forming a CO 2 molecule floating on the surface. However, when the superoxide is in the immediate vicinity of Pr dopant a carbonate-type species is formed. Our theoretical results may help to gain insight into redox properties and improved catalytic performance of low-doped Pr-CeO 2 solids. © 2016 Elsevier B.V.
format JOUR
author Milberg, B.
Juan, A.
Irigoyen, B.
author_facet Milberg, B.
Juan, A.
Irigoyen, B.
author_sort Milberg, B.
title Redox behavior of a low-doped Pr-CeO 2 (111) surface. A DFT+U study
title_short Redox behavior of a low-doped Pr-CeO 2 (111) surface. A DFT+U study
title_full Redox behavior of a low-doped Pr-CeO 2 (111) surface. A DFT+U study
title_fullStr Redox behavior of a low-doped Pr-CeO 2 (111) surface. A DFT+U study
title_full_unstemmed Redox behavior of a low-doped Pr-CeO 2 (111) surface. A DFT+U study
title_sort redox behavior of a low-doped pr-ceo 2 (111) surface. a dft+u study
url http://hdl.handle.net/20.500.12110/paper_01694332_v401_n_p206_Milberg
work_keys_str_mv AT milbergb redoxbehaviorofalowdopedprceo2111surfaceadftustudy
AT juana redoxbehaviorofalowdopedprceo2111surfaceadftustudy
AT irigoyenb redoxbehaviorofalowdopedprceo2111surfaceadftustudy
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