Origin of the Unusual Stability of Zeolite-Encapsulated Sub-Nanometer Platinum

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F20%3A10419522" target="_blank" >RIV/00216208:11310/20:10419522 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=14Fy-D24lw" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=14Fy-D24lw</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/acscatal.0c01344" target="_blank" >10.1021/acscatal.0c01344</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Origin of the Unusual Stability of Zeolite-Encapsulated Sub-Nanometer Platinum

Popis výsledku v původním jazyce

The mechanism by which single metal atoms and small, zeolite-encapsulated metal particles are stabilized against migration and growth is not currently well understood. In this work, we employ an unbiased density functional global optimization strategy to identify the locations and energetic barriers for migration pathways between sites for platinum (Pt) confined within the microporous volume of a purely silicious zeolite with Linde type A topology and its aluminosilicate and borosilicate variants. We observe an impressive stabilization of single Pt atoms caused by a hitherto unreported binding mode, in which the six rings in the framework are broken, leading to trapped, highly accessible metal centers. In addition, heteroatom substituents are found to significantly enhance the incorporation of Pt via an unexpected insertion into framework SiO-H bonds. Migration of Pt is hindered by high barriers, which are predicted to vary significantly with Si:X (X = Al and B) ratios. It is proposed that an optimal Si:X ratio exists for a given zeolite topology, in which the barriers will reach the maximum value. The energetic preference for Pt clustering (via Ostwald ripening) remains but is significantly reduced with respect to isolated clusters because of the strong interactions between Pt atoms and the framework. Our findings suggest a means to control noble-metal particle sintering, despite a thermodynamic driving force toward Pt clustering. This work provides an explanation for the surprisingly high degree of kinetic stability of ultrasmall, encapsulated metal particles observed experiment.

Název v anglickém jazyce

Origin of the Unusual Stability of Zeolite-Encapsulated Sub-Nanometer Platinum

Popis výsledku anglicky

The mechanism by which single metal atoms and small, zeolite-encapsulated metal particles are stabilized against migration and growth is not currently well understood. In this work, we employ an unbiased density functional global optimization strategy to identify the locations and energetic barriers for migration pathways between sites for platinum (Pt) confined within the microporous volume of a purely silicious zeolite with Linde type A topology and its aluminosilicate and borosilicate variants. We observe an impressive stabilization of single Pt atoms caused by a hitherto unreported binding mode, in which the six rings in the framework are broken, leading to trapped, highly accessible metal centers. In addition, heteroatom substituents are found to significantly enhance the incorporation of Pt via an unexpected insertion into framework SiO-H bonds. Migration of Pt is hindered by high barriers, which are predicted to vary significantly with Si:X (X = Al and B) ratios. It is proposed that an optimal Si:X ratio exists for a given zeolite topology, in which the barriers will reach the maximum value. The energetic preference for Pt clustering (via Ostwald ripening) remains but is significantly reduced with respect to isolated clusters because of the strong interactions between Pt atoms and the framework. Our findings suggest a means to control noble-metal particle sintering, despite a thermodynamic driving force toward Pt clustering. This work provides an explanation for the surprisingly high degree of kinetic stability of ultrasmall, encapsulated metal particles observed experiment.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10403 - Physical chemistry

Projekt

<a href="/cs/project/GJ20-26767Y" target="_blank" >GJ20-26767Y: Stabilita kovových klastrů v zeolitech: mikrokinetický model založený na ab initio a experimentálních datech</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2020

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

ACS Catalysis

ISSN

2155-5435

e-ISSN

—

Svazek periodika

10

Číslo periodika v rámci svazku

19

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

12

Strana od-do

11057-11068

Kód UT WoS článku

000577156300020

EID výsledku v databázi Scopus

2-s2.0-85096010407