Interplay between the metal- support interaction and stability in Pt/ Co3O4(111) model catalysts

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F18%3A10391197" target="_blank" >RIV/00216208:11320/18:10391197 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.1039/c8ta08142e" target="_blank" >https://doi.org/10.1039/c8ta08142e</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/c8ta08142e" target="_blank" >10.1039/c8ta08142e</a>

Result language

angličtina

Original language name

Interplay between the metal- support interaction and stability in Pt/ Co3O4(111) model catalysts

Original language description

The interplay between the metal-support interaction and stability with respect to sintering has been investigated for Pt nanoparticles supported on well-ordered Co3O4(111)/Ir(100) films in UHV and under oxidizing conditions by means of synchrotron radiation photoelectron spectroscopy (SRPES) and near ambient pressure X-ray photoelectron spectroscopy (NAP XPS). The electronic metal-support interaction between Pt and Co3O4(111) associated with charge transfer results in partial reduction of Co3O4(111) yielding partially oxidized Pt+ species at the interface. The stability of the supported Pt particles is coupled with the oxidation state of Pt+ species, which can be reduced or oxidized depending on the Pt coverage and reactive environment. Annealing of Pt/Co3O4(111)/Ir(100) in UHV triggers the reduction of Pt+ species. At higher temperature, reverse spillover of oxygen to the Pt nanoparticles is accompanied by reduction of Co3O4(111). Under these conditions, the oxidation state of Pt+ species depends strongly on Pt coverage. Thus, at low Pt coverage (0.3 ML Pt), Pt+ is converted to Pt4+, at intermediate coverage (1.3 ML Pt), Pt+ remains stable, and at high Pt coverage (1.93 ML), Pt+ is reduced to Pt-0. Sintering of Pt particles is associated with the reduction of the Pt+ species. This process is prevented under oxidizing conditions due to the formation of an interfacial oxide PtOx. The formation of an interfacial PtOx is observed at 300 K under exposure to 1 x 10(-6) mbar O-2 at Pt coverages below 1.3 ML. Using NAP XPS, we observe the formation of an interfacial PtOx at high Pt coverage (2.0 ML) in an oxygen atmosphere (1 mbar) at 300 K while the formation of surface PtOx is kinetically hindered and occurs above 550 K only.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10305 - Fluids and plasma physics (including surface physics)

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>S - Specificky vyzkum na vysokych skolach<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2018

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Journal of Materials Chemistry A

ISSN

2050-7488

e-ISSN

—

Volume of the periodical

6

Issue of the periodical within the volume

45

Country of publishing house

GB - UNITED KINGDOM

Number of pages

9

Pages from-to

23078-23086

UT code for WoS article

000451738200074

EID of the result in the Scopus database

2-s2.0-85057061637