Title :

Atmosphere-dependent stability and mobility of catalytic Pt single atoms and clusters on gamma-Al2O3

Author(s) :

Dessal, Caroline [Auteur]
Sangnier, Alexis [Auteur]
Chizallet, Celine [Auteur]
Dujardin, Christophe [Auteur]
Unité de Catalyse et Chimie du Solide (UCCS) - UMR 8181
Morfin, Franck [Auteur]
Rousset, Jean-Luc [Auteur]
Aouine, Mimoun [Auteur]
Bugnet, Matthieu [Auteur]
Afanasiev, Pavel [Auteur]
Piccolo, Laurent [Auteur]

Journal title :

Nanoscale

Abbreviated title :

Nanoscale

Publication date :

2019-03-26

ISSN :

2040-3372

HAL domain(s) :

Chimie/Catalyse

English abstract : [en]

Atomically dispersed metals promise the ultimate catalytic efficiency, but their stabilization onto suitable supports remains challenging owing to their aggregation tendency. Focusing on the industrially-relevant Pt/γ-Al2O3 ...
Show more >Atomically dispersed metals promise the ultimate catalytic efficiency, but their stabilization onto suitable supports remains challenging owing to their aggregation tendency. Focusing on the industrially-relevant Pt/γ-Al2O3 catalyst, in situ X-ray absorption spectroscopy and environmental scanning transmission electron microscopy allow us to monitor the stabilization of Pt single atoms under O2 atmosphere, as well as their aggregation into mobile reduced subnanometric clusters under H2. Density functional theory calculations reveal that oxygen from the gas phase directly contributes to metal-support adhesion, maximal for single Pt atoms, whereas hydrogen only adsorbs on Pt, and thereby leads to Pt clustering. Finally, Pt cluster mobility is shown to be activated at low temperature and high H2 pressure. Our results highlight the crucial importance of the reactive atmosphere on the stability of single-atom versus cluster catalysts.Show less >

Language :

Anglais

Audience :

Internationale

Popular science :

Non

Administrative institution(s) :

CNRS
Centrale Lille
ENSCL
Univ. Artois
Université de Lille

Collections :

• Unité de Catalyse et Chimie du Solide (UCCS) - UMR 8181

Research team(s) :

Remédiation et matériaux catalytiques (REMCAT)

Submission date :

2022-03-02T07:13:13Z
2024-02-05T17:00:58Z