In Situ Spectroscopy and Microscopy Insights into the CO Oxidation Mechanism on Au/CeO2(111)

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F22%3A10456752" target="_blank" >RIV/00216208:11320/22:10456752 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=_bfBu2VjD7" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=_bfBu2VjD7</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/acsami.2c15792" target="_blank" >10.1021/acsami.2c15792</a>

Jazyk výsledku

angličtina

Název v původním jazyce

In Situ Spectroscopy and Microscopy Insights into the CO Oxidation Mechanism on Au/CeO2(111)

Popis výsledku v původním jazyce

In this work, we prepared and investigated in ultrahigh vacuum (UHV) two stoichiometric CeO2(111) surfaces containing low and high amounts of step edges decorated with 0.05 ML of gold using synchrotron-radiation photoelectron spectroscopy (SRPES) and scanning tunneling microscopy (STM). The UHV study helped to solve the still unresolved puzzle on how the one-monolayer-high ceria step edges affect the metal- substrate interaction between Au and the CeO2(111) surface. It was found that the concentration of ionic Au+ species on the ceria surface increases with increasing number of ceria step edges and is not correlated with the concentration of Ce3+ ions that are supposed to form on the surface after its interaction with gold nanoparticles. We associated this with an additional channel of Au+ formation on the surface of CeO2(111) related to the interaction of Au atoms with various peroxo oxygen species formed at the ceria step edges during the film growth. The study of CO oxidation on the highly stepped Au/CeO2(111) model sample was performed by combining near-ambient-pressure X-ray photoelectron spectroscopy (NAP-XPS), UHV-STM, and near-ambient-pressure STM (NAP-STM). This powerful combination provided comprehensive information on the processes occurring on the Au/CeO2(111) surface during the interaction with CO, O2, and CO + O2 (1:1) mixture at conditions close to the real working conditions of CO oxidation. It was found that the system demonstrates high stability in CO. However, the surface undergoes substantial chemical and morphological changes as the O2 is added to the reaction cell. Already at 300 K, gold nanoparticles begin to grow using a mechanism that involves the disintegration of small gold nanoparticles in favor of the large ones. With increasing temperature, the model catalyst quickly transforms into a system of primarily large Au particles that contains no ionic gold species.

Název v anglickém jazyce

In Situ Spectroscopy and Microscopy Insights into the CO Oxidation Mechanism on Au/CeO2(111)

Popis výsledku anglicky

In this work, we prepared and investigated in ultrahigh vacuum (UHV) two stoichiometric CeO2(111) surfaces containing low and high amounts of step edges decorated with 0.05 ML of gold using synchrotron-radiation photoelectron spectroscopy (SRPES) and scanning tunneling microscopy (STM). The UHV study helped to solve the still unresolved puzzle on how the one-monolayer-high ceria step edges affect the metal- substrate interaction between Au and the CeO2(111) surface. It was found that the concentration of ionic Au+ species on the ceria surface increases with increasing number of ceria step edges and is not correlated with the concentration of Ce3+ ions that are supposed to form on the surface after its interaction with gold nanoparticles. We associated this with an additional channel of Au+ formation on the surface of CeO2(111) related to the interaction of Au atoms with various peroxo oxygen species formed at the ceria step edges during the film growth. The study of CO oxidation on the highly stepped Au/CeO2(111) model sample was performed by combining near-ambient-pressure X-ray photoelectron spectroscopy (NAP-XPS), UHV-STM, and near-ambient-pressure STM (NAP-STM). This powerful combination provided comprehensive information on the processes occurring on the Au/CeO2(111) surface during the interaction with CO, O2, and CO + O2 (1:1) mixture at conditions close to the real working conditions of CO oxidation. It was found that the system demonstrates high stability in CO. However, the surface undergoes substantial chemical and morphological changes as the O2 is added to the reaction cell. Already at 300 K, gold nanoparticles begin to grow using a mechanism that involves the disintegration of small gold nanoparticles in favor of the large ones. With increasing temperature, the model catalyst quickly transforms into a system of primarily large Au particles that contains no ionic gold species.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10305 - Fluids and plasma physics (including surface physics)

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2022

Kód důvěrnosti údajů

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

Název periodika

ACS Applied Materials &amp; Interfaces

ISSN

1944-8244

e-ISSN

1944-8252

Svazek periodika

14

Číslo periodika v rámci svazku

50

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

10

Strana od-do

56280-56289

Kód UT WoS článku

000895462200001

EID výsledku v databázi Scopus

2-s2.0-85143856375