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Identification of Subnanometric Ag Species, Their Interaction with Supports and Role in Catalytic CO Oxidation

The nature and size of the real active species of nanoparticulated metal supported catalysts is still an unresolved question. The technique of choice to measure particle sizes at the nanoscale, HRTEM, has a practical limit of 1 nm. This work is aimed to identify the catalytic role of subnanometer sp...

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Autores principales: Kotolevich, Yulia, Kolobova, Ekaterina, Khramov, Evgeniy, Cabrera Ortega, Jesús Efren, Farías, Mario H., Zubavichus, Yan, Zanella, Rodolfo, Mota-Morales, Josué D., Pestryakov, Alexey, Bogdanchikova, Nina, Cortés Corberán, Vicente
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6273660/
https://www.ncbi.nlm.nih.gov/pubmed/27110757
http://dx.doi.org/10.3390/molecules21040532
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author Kotolevich, Yulia
Kolobova, Ekaterina
Khramov, Evgeniy
Cabrera Ortega, Jesús Efren
Farías, Mario H.
Zubavichus, Yan
Zanella, Rodolfo
Mota-Morales, Josué D.
Pestryakov, Alexey
Bogdanchikova, Nina
Cortés Corberán, Vicente
author_facet Kotolevich, Yulia
Kolobova, Ekaterina
Khramov, Evgeniy
Cabrera Ortega, Jesús Efren
Farías, Mario H.
Zubavichus, Yan
Zanella, Rodolfo
Mota-Morales, Josué D.
Pestryakov, Alexey
Bogdanchikova, Nina
Cortés Corberán, Vicente
author_sort Kotolevich, Yulia
collection PubMed
description The nature and size of the real active species of nanoparticulated metal supported catalysts is still an unresolved question. The technique of choice to measure particle sizes at the nanoscale, HRTEM, has a practical limit of 1 nm. This work is aimed to identify the catalytic role of subnanometer species and methods to detect and characterize them. In this frame, we investigated the sensitivity to redox pretreatments of Ag/Fe/TiO(2), Ag/Mg/TiO(2) and Ag/Ce/TiO(2) catalysts in CO oxidation. The joint application of HRTEM, SR-XRD, DRS, XPS, EXAFS and XANES methods indicated that most of the silver in all samples is in the form of Ag species with size <1 nm. The differences in catalytic properties and sensitivity to pretreatments, observed for the studied Ag catalysts, could not be explained taking into account only the Ag particles whose size distribution is measured by HRTEM, but may be explained by the presence of the subnanometer Ag species, undetectable by HRTEM, and their interaction with supports. This result highlights their role as active species and the need to take them into account to understand integrally the catalysis by supported nanometals.
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spelling pubmed-62736602018-12-28 Identification of Subnanometric Ag Species, Their Interaction with Supports and Role in Catalytic CO Oxidation Kotolevich, Yulia Kolobova, Ekaterina Khramov, Evgeniy Cabrera Ortega, Jesús Efren Farías, Mario H. Zubavichus, Yan Zanella, Rodolfo Mota-Morales, Josué D. Pestryakov, Alexey Bogdanchikova, Nina Cortés Corberán, Vicente Molecules Article The nature and size of the real active species of nanoparticulated metal supported catalysts is still an unresolved question. The technique of choice to measure particle sizes at the nanoscale, HRTEM, has a practical limit of 1 nm. This work is aimed to identify the catalytic role of subnanometer species and methods to detect and characterize them. In this frame, we investigated the sensitivity to redox pretreatments of Ag/Fe/TiO(2), Ag/Mg/TiO(2) and Ag/Ce/TiO(2) catalysts in CO oxidation. The joint application of HRTEM, SR-XRD, DRS, XPS, EXAFS and XANES methods indicated that most of the silver in all samples is in the form of Ag species with size <1 nm. The differences in catalytic properties and sensitivity to pretreatments, observed for the studied Ag catalysts, could not be explained taking into account only the Ag particles whose size distribution is measured by HRTEM, but may be explained by the presence of the subnanometer Ag species, undetectable by HRTEM, and their interaction with supports. This result highlights their role as active species and the need to take them into account to understand integrally the catalysis by supported nanometals. MDPI 2016-04-22 /pmc/articles/PMC6273660/ /pubmed/27110757 http://dx.doi.org/10.3390/molecules21040532 Text en © 2016 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons by Attribution (CC-BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Kotolevich, Yulia
Kolobova, Ekaterina
Khramov, Evgeniy
Cabrera Ortega, Jesús Efren
Farías, Mario H.
Zubavichus, Yan
Zanella, Rodolfo
Mota-Morales, Josué D.
Pestryakov, Alexey
Bogdanchikova, Nina
Cortés Corberán, Vicente
Identification of Subnanometric Ag Species, Their Interaction with Supports and Role in Catalytic CO Oxidation
title Identification of Subnanometric Ag Species, Their Interaction with Supports and Role in Catalytic CO Oxidation
title_full Identification of Subnanometric Ag Species, Their Interaction with Supports and Role in Catalytic CO Oxidation
title_fullStr Identification of Subnanometric Ag Species, Their Interaction with Supports and Role in Catalytic CO Oxidation
title_full_unstemmed Identification of Subnanometric Ag Species, Their Interaction with Supports and Role in Catalytic CO Oxidation
title_short Identification of Subnanometric Ag Species, Their Interaction with Supports and Role in Catalytic CO Oxidation
title_sort identification of subnanometric ag species, their interaction with supports and role in catalytic co oxidation
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6273660/
https://www.ncbi.nlm.nih.gov/pubmed/27110757
http://dx.doi.org/10.3390/molecules21040532
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