2020
DOI: 10.1021/acscatal.9b05431
|View full text |Cite
|
Sign up to set email alerts
|

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

Abstract: 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… Show more

Help me understand this report

Search citation statements

Order By: Relevance

Paper Sections

Select...
1
1
1
1

Citation Types

2
32
0

Year Published

2020
2020
2024
2024

Publication Types

Select...
9

Relationship

2
7

Authors

Journals

citations
Cited by 45 publications
(34 citation statements)
references
References 170 publications
2
32
0
Order By: Relevance
“…Synthetic heterogeneous catalyst design in this context has been heavily focused on Fe‐ and Cu‐exchanged zeolites, [4–8] in part inspired by existing proposals for active site structures prevalent in monooxygenase enzymes [9–11] . The study and development of iron‐modified zeolite catalysts, however, is significantly hampered by the highly heterogenous nature of iron speciation, the distribution and prevalence of which is contingent on many factors such as synthesis procedure, activation method, and total iron content (Table S1) [12–15] . For example, Fe−O, Fe−Fe, and Fe−Si/Al distances compiled from EXAFS data reported in the Fe‐ZSM‐5 literature evidence a range of first‐shell distances even at the lowest iron loadings evaluated (0.2 wt %, Figure S1).…”
Section: Methodsmentioning
confidence: 99%
See 1 more Smart Citation
“…Synthetic heterogeneous catalyst design in this context has been heavily focused on Fe‐ and Cu‐exchanged zeolites, [4–8] in part inspired by existing proposals for active site structures prevalent in monooxygenase enzymes [9–11] . The study and development of iron‐modified zeolite catalysts, however, is significantly hampered by the highly heterogenous nature of iron speciation, the distribution and prevalence of which is contingent on many factors such as synthesis procedure, activation method, and total iron content (Table S1) [12–15] . For example, Fe−O, Fe−Fe, and Fe−Si/Al distances compiled from EXAFS data reported in the Fe‐ZSM‐5 literature evidence a range of first‐shell distances even at the lowest iron loadings evaluated (0.2 wt %, Figure S1).…”
Section: Methodsmentioning
confidence: 99%
“…[9][10][11] The study and development of iron-modified zeolite catalysts, however,i ss ignificantlyh ampered by the highly heterogenous natureo fi ron speciation, the distribution and prevalence of which is contingent on many factors such as synthesis procedure, activationm ethod, and total iron content (Table S1). [12][13][14][15] For example, FeÀO, FeÀFe, and FeÀSi/Al distances compiled from EXAFSd ata reported in the Fe-ZSM-5l iterature evidencearange of first-shell distances even at the lowest iron loadings evaluated (0.2 wt %, FigureS1). Such heterogeneity in site speciation not only leads to limitations in the decipherability of active site structure but also renders merely the differentiation of active sites from inactive ones extremely challenging!W ea ssert that despite decades of research,e vidence of ah eterogeneous iron-based catalystt hat is comprised exclusivelyo fi ron moieties that are active in the low-temperature conversion of methane to methanol has not been reported thus far in the literature.…”
mentioning
confidence: 99%
“…[34] In turn, the cationic sites containing two Al atoms can stabilize bare Cu 2 + ions or Cu bridging species. [54] Due to the geometric constraints of the six-ring controlling the access to the Cu 2 + ions located in the ω, ω 3Si sites and pseudo octahedral coordination of Cu 2 + ions in these sites to the framework oxygens, the Cu 2 + ions in these sites can be supposed to adsorb guest molecules with difficulties.…”
Section: Determination Of the Copper And Bas Sites By Ir Measurements...mentioning
confidence: 99%
“…8000 fs) when the system fluctuated around the equilibrium and "snapshots" were collected and optimized. Similar time lengths were used for MD simulations of cationic sites in zeolites [4,15,[40][41][42]. The MD simulations serve to obtain the rearranged local structures (details are provided in our prior studies [14,24]).…”
Section: Molecular Dynamicsmentioning
confidence: 99%