April 22 - 26, 2024
Seattle, Washington
May 7 - 9, 2024 (Virtual)

Event Supporters

2024 MRS Spring Meeting
CH04.10.08

Unraveling The Catalytic Effect of Hydrogen Adsorption on Pt Nanoparticle Shape-Change

When and Where

Apr 26, 2024
10:15am - 10:30am
Room 443, Level 4, Summit

Presenter(s)

Co-Author(s)

Cameron Owen1,Nicholas Marcella2,Yu Xie1,Jonathan Vandermause1,Anatoly Frenkel3,4,Ralph Nuzzo2,Boris Kozinsky1,5

Harvard University1,University of Illinois at Urbana-Champaign2,Stony Brook University, The State University of New York3,Brookhaven National Laboratory4,Robert Bosch LLC5

Abstract

Cameron Owen1,Nicholas Marcella2,Yu Xie1,Jonathan Vandermause1,Anatoly Frenkel3,4,Ralph Nuzzo2,Boris Kozinsky1,5

Harvard University1,University of Illinois at Urbana-Champaign2,Stony Brook University, The State University of New York3,Brookhaven National Laboratory4,Robert Bosch LLC5
The activity of metal catalysts depends sensitively on dynamic structural changes that occur during operating conditions. The mechanistic understanding underlying such transformations in small Pt nanoparticles (NPs) of ~1-5 nm in diameter, commonly used in hydrogenation reactions, is currently far from complete. In this study, we investigate the structural evolution of Pt NPs in the presence of hydrogen using long time-scale reactive molecular dynamics (MD) simulations paired with experimental X-ray absorption spectroscopy. From these comparisons, we obtain atomic-level mechanistic insights into `order-disorder' structural transformations exhibited by highly dispersed Pt NP catalysts upon exposure to hydrogen. We report the emergence of previously unknown candidate structures in the 1 nm Pt NP size range, where exposure to hydrogen leads to the appearance of a `quasi-icosahedral' intermediate symmetry, followed by the formation of `rosettes' on the NP surface. Hydrogen adsorption is found to catalyze these shape transitions by lowering their temperatures and increasing the apparent rates at which these candidate structures appear, revealing the mutually catalytic and dynamic nature of interaction between nanoparticle and adsorbate. This study offers a new pathway for deciphering the reversible evolution of catalyst structure resulting from the chemisorption of reactive species, enabling the determination of active sites and improved interpretation of experimental results with atomic resolution.

Keywords

nanostructure

Symposium Organizers

Yuzi Liu, Argonne National Laboratory
Michelle Mejía, Dow Chemical Co
Yang Yang, Brookhaven National Laboratory
Xingchen Ye, Indiana University

Session Chairs

Tianyi Li
Michelle Mejía
Yang Yang

In this Session