Does Cluster Encapsulation Inhibit Sintering? Stabilization of Size-Selected Pt Clusters on Fe3O4(001) by SMSI
(2023) In ACS Catalysis 13(9). p.6203-6213- Abstract
The metastability of supported metal nanoparticles limits their application in heterogeneous catalysis at elevated temperatures due to their tendency to sinter. One strategy to overcome these thermodynamic limits on reducible oxide supports is encapsulation via strong metal-support interaction (SMSI). While annealing-induced encapsulation is a well-explored phenomenon for extended nanoparticles, it is as yet unknown whether the same mechanisms hold for subnanometer clusters, where concomitant sintering and alloying might play a significant role. In this article, we explore the encapsulation and stability of size-selected Pt5, Pt10, and Pt19 clusters deposited on Fe3O4(001). In a... (More)
The metastability of supported metal nanoparticles limits their application in heterogeneous catalysis at elevated temperatures due to their tendency to sinter. One strategy to overcome these thermodynamic limits on reducible oxide supports is encapsulation via strong metal-support interaction (SMSI). While annealing-induced encapsulation is a well-explored phenomenon for extended nanoparticles, it is as yet unknown whether the same mechanisms hold for subnanometer clusters, where concomitant sintering and alloying might play a significant role. In this article, we explore the encapsulation and stability of size-selected Pt5, Pt10, and Pt19 clusters deposited on Fe3O4(001). In a multimodal approach using temperature-programmed desorption (TPD), X-ray photoelectron spectroscopy (XPS), and scanning tunneling microscopy (STM), we demonstrate that SMSI indeed leads to the formation of a defective, FeO-like conglomerate encapsulating the clusters. By stepwise annealing up to 1023 K, we observe the succession of encapsulation, cluster coalescence, and Ostwald ripening, resulting in square-shaped crystalline Pt particles, independent of the initial cluster size. The respective sintering onset temperatures scale with the cluster footprint and thus size. Remarkably, while small encapsulated clusters can still diffuse as a whole, atom detachment and thus Ostwald ripening are successfully suppressed up to 823 K, i.e., 200 K above the Hüttig temperature that indicates the thermodynamic stability limit.
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- author
- Kaiser, Sebastian ; Plansky, Johanna ; Krinninger, Matthias ; Shavorskiy, Andrey LU ; Zhu, Suyun LU ; Heiz, Ueli ; Esch, Friedrich and Lechner, Barbara A.J.
- organization
- publishing date
- 2023-05
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- encapsulation, heterogeneous catalysis, scanning tunneling microscopy, sintering, size-selected clusters, strong metal−support interaction, temperature-programmed desorption, X-ray photoelectron spectroscopy
- in
- ACS Catalysis
- volume
- 13
- issue
- 9
- pages
- 11 pages
- publisher
- The American Chemical Society (ACS)
- external identifiers
-
- pmid:37180966
- scopus:85154042308
- ISSN
- 2155-5435
- DOI
- 10.1021/acscatal.3c00448
- language
- English
- LU publication?
- yes
- id
- 8ceb6caf-b390-47cf-8bfe-7243b710253a
- date added to LUP
- 2023-07-14 11:22:28
- date last changed
- 2024-12-29 01:22:38
@article{8ceb6caf-b390-47cf-8bfe-7243b710253a,
abstract = {{<p>The metastability of supported metal nanoparticles limits their application in heterogeneous catalysis at elevated temperatures due to their tendency to sinter. One strategy to overcome these thermodynamic limits on reducible oxide supports is encapsulation via strong metal-support interaction (SMSI). While annealing-induced encapsulation is a well-explored phenomenon for extended nanoparticles, it is as yet unknown whether the same mechanisms hold for subnanometer clusters, where concomitant sintering and alloying might play a significant role. In this article, we explore the encapsulation and stability of size-selected Pt<sub>5</sub>, Pt<sub>10</sub>, and Pt<sub>19</sub> clusters deposited on Fe<sub>3</sub>O<sub>4</sub>(001). In a multimodal approach using temperature-programmed desorption (TPD), X-ray photoelectron spectroscopy (XPS), and scanning tunneling microscopy (STM), we demonstrate that SMSI indeed leads to the formation of a defective, FeO-like conglomerate encapsulating the clusters. By stepwise annealing up to 1023 K, we observe the succession of encapsulation, cluster coalescence, and Ostwald ripening, resulting in square-shaped crystalline Pt particles, independent of the initial cluster size. The respective sintering onset temperatures scale with the cluster footprint and thus size. Remarkably, while small encapsulated clusters can still diffuse as a whole, atom detachment and thus Ostwald ripening are successfully suppressed up to 823 K, i.e., 200 K above the Hüttig temperature that indicates the thermodynamic stability limit.</p>}},
author = {{Kaiser, Sebastian and Plansky, Johanna and Krinninger, Matthias and Shavorskiy, Andrey and Zhu, Suyun and Heiz, Ueli and Esch, Friedrich and Lechner, Barbara A.J.}},
issn = {{2155-5435}},
keywords = {{encapsulation; heterogeneous catalysis; scanning tunneling microscopy; sintering; size-selected clusters; strong metal−support interaction; temperature-programmed desorption; X-ray photoelectron spectroscopy}},
language = {{eng}},
number = {{9}},
pages = {{6203--6213}},
publisher = {{The American Chemical Society (ACS)}},
series = {{ACS Catalysis}},
title = {{Does Cluster Encapsulation Inhibit Sintering? Stabilization of Size-Selected Pt Clusters on Fe<sub>3</sub>O<sub>4</sub>(001) by SMSI}},
url = {{http://dx.doi.org/10.1021/acscatal.3c00448}},
doi = {{10.1021/acscatal.3c00448}},
volume = {{13}},
year = {{2023}},
}