Atmosphere-dependent stability and mobility of catalytic Pt single atoms and clusters on gamma-Al2O3 - IFPEN - IFP Energies nouvelles Access content directly
Journal Articles Nanoscale Year : 2019

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

Céline Chizallet

Abstract

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/-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.
Fichier principal
Vignette du fichier
Atmosphere Dependent Stability Sup mat.pdf (929.04 Ko) Télécharger le fichier
Atmosphere Dependent Stability Sup mat 2.pdf (2.11 Mo) Télécharger le fichier
c9nr01641d1.avi (10.11 Mo) Télécharger le fichier
c9nr01641d2.avi (14.41 Mo) Télécharger le fichier
Origin : Files produced by the author(s)
Loading...

Dates and versions

hal-02142310 , version 1 (28-05-2019)

Identifiers

Cite

Caroline Dessal, Alexis Sangnier, Céline Chizallet, Christophe Dujardin, Franck Morfin, et al.. Atmosphere-dependent stability and mobility of catalytic Pt single atoms and clusters on gamma-Al2O3. Nanoscale, 2019, 11 (14), pp.6897-6904. ⟨10.1039/C9NR01641D⟩. ⟨hal-02142310⟩
251 View
468 Download

Altmetric

Share

Gmail Facebook X LinkedIn More