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

Journal Molecules
ISSN: 1420-3049
Output data Year: 2016, Volume: 21, Number: 4, Article number : 532, Pages count : 18 DOI: 10.3390/molecules21040532
Tags CO oxidation; Interaction with support; Sensitivity to pretreatments; Silver catalysts; Subnanometer species
Authors Kotolevich Yulia 1 , Kolobova Ekaterina 2 , Khramov Evgeniy 3 , Cabrera Ortega Jesús Efren 4 , Farías Mario H. 1 , Zubavichus Yan 3 , Zanella Rodolfo 5 , Mota-Morales Josué D. 1,6 , Pestryakov Alexey 2 , Bogdanchikova Nina 1 , Cortés Corberán Vicente 7
Affiliations
1 Departamento de Fisicoquímica de Nanomateriales, Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México (UNAM)
2 Department of Physical and Analytical Chemistry, Tomsk Polytechnic University
3 National Research Center “Kurchatov Institute”
4 Departamento de Fisica Aplicada, Centro de Investigación Científica y de Educación Superior de Ensenada
5 Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México (UNAM)
6 CONACYT Research Fellow at Centro de Nanociencias y Nanotecnología, UNAM
7 Institute of Catalysis and Petroleumchemistry (ICP), Spanish Council for Scientific Research (CSIC)

Abstract: 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/TiO2, Ag/Mg/TiO2 and Ag/Ce/TiO2 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.
Cite: Kotolevich Y. , Kolobova E. , Khramov E. , Cabrera Ortega J.E. , Farías M.H. , Zubavichus Y. , Zanella R. , Mota-Morales J.D. , Pestryakov A. , Bogdanchikova N. , Cortés Corberán V.
Identification of Subnanometric Ag Species, Their Interaction with Supports and Role in Catalytic CO Oxidation
Molecules. 2016. V.21. N4. 532 :1-18. DOI: 10.3390/molecules21040532 WOS Scopus РИНЦ AN OpenAlex
Files: Full text from publisher
Dates:
Submitted: Feb 6, 2016
Accepted: Apr 15, 2016
Published print: Apr 22, 2016
Published online: Apr 22, 2016
Identifiers:
Web of science: WOS:000375155000139
Scopus: 2-s2.0-84969622275
Elibrary: 27156407
Chemical Abstracts: 2016:1517635
OpenAlex: W2341960401
Citing:
DB Citing
Web of science 10
Scopus 13
OpenAlex 12
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