Title: Reagent-Triggered Isomerization of Fluxional Cluster Catalyst via Dynamic Coupling

Abstract

Metallic cluster catalysts have many thermodynamically accessible isomers with diverse active sites and low reaction barriers, and lately a strong hypothesis emerged that the many catalyst states collectively drive the catalysis. Furthermore, it remained a hypothesis that catalyst isomerization is actually kinetically feasible under the current reaction conditions. Using high-temperature dynamics simulations and sampling, a range of orientations, and vibrational energy distributions, we probe how thermal effects and molecular events affect cluster catalyst dynamics. We show that even such a delicate affair as the dissociation or scattering of a methane molecule on the heavy and thus slow Pt₁₃ cluster triggers substantial isomerization of the catalyst, far beyond thermal at 700 K. A kinetic coupling between the methane activity and cluster catalyst dynamics is observed. In return, the thermal dynamics of the cluster affects the methane reaction and scattering probabilities. Hence, molecular events at the surfaces of fluxional cluster catalysts should facilitate the population of an ensemble of catalyst states under the current reaction conditions, with implications for available active sites, reaction mechanisms, and apparent rates.

Authors:

Guo, Han  ^[1];

• Search DOE PAGES for author "Guo, Han"
• Search DOE PAGES for ORCID "0000-0001-7695-9080"

Sautet, Philippe  ^[2];

• Search DOE PAGES for author "Sautet, Philippe"
• Search DOE PAGES for ORCID "0000-0002-8444-3348"

Alexandrova, Anastassia N.  ^[2]

• Search DOE PAGES for author "Alexandrova, Anastassia N."
• Search DOE PAGES for ORCID "0000-0002-3003-1911"

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+ Show Author Affiliations

1. Univ. of California, Los Angeles, CA (United States)
2. Univ. of California, Los Angeles, CA (United States); California NanoSystems Inst., Los Angeles, CA (United States)

Publication Date:

Mon Mar 30 00:00:00 EDT 2020

Research Org.:

Univ. of California, Los Angeles, CA (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES). Scientific User Facilities Division

OSTI Identifier:

1755397

Grant/Contract Number:  

SC0019152; AC02-05CH11231; AC02-06CH11357

Resource Type:

Accepted Manuscript

Journal Name:

Journal of Physical Chemistry Letters

Additional Journal Information:

Journal Volume: 11; Journal Issue: 8; Journal ID: ISSN 1948-7185

Publisher:

American Chemical Society

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Hydrocarbons; Platinum; Catalysts; Cluster chemistry; Computational chemistry