Atomically Dispersed Pd, Ni, and Pt Species in Ceria-Based Catalysts: Principal Differences in Stability and Reactivity

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F16%3A10334198" target="_blank" >RIV/00216208:11320/16:10334198 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=Dqh0EN-UfD" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=Dqh0EN-UfD</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/acs.jpcc.6b02264" target="_blank" >10.1021/acs.jpcc.6b02264</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Atomically Dispersed Pd, Ni, and Pt Species in Ceria-Based Catalysts: Principal Differences in Stability and Reactivity

Popis výsledku v původním jazyce

We have investigated the stability and the reactivity of atomically dispersed Pt, Pd, and Ni species on nanostructured CeO2 films by means of synchrotron radiation photoelectron spectroscopy and resonant photoemission spectroscopy in combination with density functional calculations. All three metals reveal specific similarities associated with the high adsorption energy of atomically dispersed Pt2+, Pd2+, and Ni2+ species that exceeds the corresponding cohesive energies of the bulk metals. The corresponding Pt-CeO2, Pd-CeO2, and Ni-CeO2 model catalysts have been prepared in the form of thin films on CeO2(111)/Cu(111) substrates and investigated experimentally under ultrahigh vacuum conditions. The atomically dispersed Pt2+, Pd2+, and Ni-2 species were formed exclusively at low concentrations of the corresponding metals. High concentrations resulted in the presence of additional metal oxide phases and emergence of metallic particles. We found that under the employed experimental conditions the Pd-CeO2 films closely resemble the Pt-CeO2 system with respect to the redox behavior upon reaction with hydrogen. Unlike Pt-CeO2, the Pd-CeO2 system shows a strong tendency to stabilize Pd2+ not only at the surface but also in the ceria bulk. In sharp contrast to both Pt-CeO2 and Pd-CeO2, the Ni-CeO2 system does not exhibit the redox functionality required for hydrogen activation due to the remarkably high stability of Ni2+ species.

Název v anglickém jazyce

Atomically Dispersed Pd, Ni, and Pt Species in Ceria-Based Catalysts: Principal Differences in Stability and Reactivity

Popis výsledku anglicky

We have investigated the stability and the reactivity of atomically dispersed Pt, Pd, and Ni species on nanostructured CeO2 films by means of synchrotron radiation photoelectron spectroscopy and resonant photoemission spectroscopy in combination with density functional calculations. All three metals reveal specific similarities associated with the high adsorption energy of atomically dispersed Pt2+, Pd2+, and Ni2+ species that exceeds the corresponding cohesive energies of the bulk metals. The corresponding Pt-CeO2, Pd-CeO2, and Ni-CeO2 model catalysts have been prepared in the form of thin films on CeO2(111)/Cu(111) substrates and investigated experimentally under ultrahigh vacuum conditions. The atomically dispersed Pt2+, Pd2+, and Ni-2 species were formed exclusively at low concentrations of the corresponding metals. High concentrations resulted in the presence of additional metal oxide phases and emergence of metallic particles. We found that under the employed experimental conditions the Pd-CeO2 films closely resemble the Pt-CeO2 system with respect to the redox behavior upon reaction with hydrogen. Unlike Pt-CeO2, the Pd-CeO2 system shows a strong tendency to stabilize Pd2+ not only at the surface but also in the ceria bulk. In sharp contrast to both Pt-CeO2 and Pd-CeO2, the Ni-CeO2 system does not exhibit the redox functionality required for hydrogen activation due to the remarkably high stability of Ni2+ 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

2016

Kód důvěrnosti údajů

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

Název periodika

Journal of Physical Chemistry C

ISSN

1932-7447

e-ISSN

—

Svazek periodika

120

Číslo periodika v rámci svazku

18

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

11

Strana od-do

9852-9862

Kód UT WoS článku

000375969000035

EID výsledku v databázi Scopus

2-s2.0-84971255027