Effect of the Nuclearity and Coordination of Cu and Fe Sites in beta Zeolites on the Oxidation of Hydrocarbons

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388955%3A_____%2F20%3A00524176" target="_blank" >RIV/61388955:_____/20:00524176 - isvavai.cz</a>

Výsledek na webu

<a href="http://hdl.handle.net/11104/0308541" target="_blank" >http://hdl.handle.net/11104/0308541</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/acscatal.9b05431" target="_blank" >10.1021/acscatal.9b05431</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Effect of the Nuclearity and Coordination of Cu and Fe Sites in beta Zeolites on the Oxidation of Hydrocarbons

Popis výsledku v původním jazyce

Cu and Fe zeolites can activate oxygen for oxidative reactions of methane and stable hydrocarbon molecules. Here, we analyzed the activity of Cu and Fe sites with various nuclearities and coordinations in *BEA zeolites toward complete oxidation of methane, toluene, and ethanol by molecular oxygen. Spectral analysis of the interaction of methane with the individual Cu and Fe sites and a kinetic study show that the oxidation of methane is catalyzed by different active sites with different activation energies. In the low-temperature region (225-325 degrees C), the activity is primarily caused by reactive bridging oxygen atoms in dimeric Cu and Fe clusters. Isolated Fe3+-oxo ions in the octahedral coordination and Cu2+ partially charge-balanced by the framework with less rigid redox states contribute to the activity at higher temperatures of >= 350 degrees C. The isolated Fe3+-oxo ions tetrahedrally coordinated to the framework oxygen and the bare Cu2+ ions charge-balanced exclusively by the framework are strongly stabilized and cannot act as active sites. Oxidation of the hydrocarbons over both the dimeric and isolated Cu and Fe active sites is nonspecific with practically barrierless consecutive reactions of already activated molecules and therefore fully CO2-selective for all of the hydrocarbons in an excess of oxygen.

Název v anglickém jazyce

Effect of the Nuclearity and Coordination of Cu and Fe Sites in beta Zeolites on the Oxidation of Hydrocarbons

Popis výsledku anglicky

Cu and Fe zeolites can activate oxygen for oxidative reactions of methane and stable hydrocarbon molecules. Here, we analyzed the activity of Cu and Fe sites with various nuclearities and coordinations in *BEA zeolites toward complete oxidation of methane, toluene, and ethanol by molecular oxygen. Spectral analysis of the interaction of methane with the individual Cu and Fe sites and a kinetic study show that the oxidation of methane is catalyzed by different active sites with different activation energies. In the low-temperature region (225-325 degrees C), the activity is primarily caused by reactive bridging oxygen atoms in dimeric Cu and Fe clusters. Isolated Fe3+-oxo ions in the octahedral coordination and Cu2+ partially charge-balanced by the framework with less rigid redox states contribute to the activity at higher temperatures of >= 350 degrees C. The isolated Fe3+-oxo ions tetrahedrally coordinated to the framework oxygen and the bare Cu2+ ions charge-balanced exclusively by the framework are strongly stabilized and cannot act as active sites. Oxidation of the hydrocarbons over both the dimeric and isolated Cu and Fe active sites is nonspecific with practically barrierless consecutive reactions of already activated molecules and therefore fully CO2-selective for all of the hydrocarbons in an excess of oxygen.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10403 - Physical chemistry

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

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

7

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

19

Strana od-do

3984-4002

Kód UT WoS článku

000526395000004

EID výsledku v databázi Scopus

2-s2.0-85084083134