Repository of University of Nova Gorica

Show document
A+ | A- | SLO | ENG

Title:New Insights into Manganese Local Environment in MnS-1Nanocrystals
Authors:Ristić, Alenka (Author)
Mazaj, Matjaž (Author)
Arčon, Iztok (Author)
Daneu, Nina (Author)
Zabukovec Logar, Nataša (Author)
Glaser, Roger (Author)
Novak Tušar, Nataša (Author)
Files:This document has no files. This document may have a phisical copy in the library of the organization, check the status via COBISS. Link is opened in a new window
Language:English
Work type:Not categorized (r6)
Tipology:1.01 - Original Scientific Article
Organization:UNG - University of Nova Gorica
Abstract:Manganese plays an important role in redox catalysis using zeolites as inorganic support materials, but the formation of the preferred redox manganese species (framework or extraframework) is still not well understood. Herein, the influence of the amount of manganese together with conventional and microwave-assisted hydrothermal synthesis paths on the formation of manganese species within the zeolite silicalite-1 (S-1) with MFI structure was investigated. It was found out that both synthesis procedures led to the formation of framework and extraframework manganese species, but in different molar ratios. However, the conventional synthesis procedure with all Mn/Si molar ratios generates more framework Mn in comparison to the microwave procedure. Additionally, the diminution of the zeolite crystals to nanoscale from 100 to 200 nm was achieved via the conventional procedure for the first time. UV–vis, Raman, and X-ray absorption spectroscopic analyses revealed different local environments of manganese: Mn3+ incorporated into the silicalite-1 framework as “framework manganese” and Mn2+/3+ present as “extraframework manganese” (Mn2O3, Mn3O4). TEM reveals the presence of Mn3O4 nanorods. Both framework manganese and extraframework manganese exhibit good catalytic activity for styrene epoxidation. Catalytic results suggest that, in oxidation reactions of hydrocarbons, framework manganese is more active at lower Mn contents (Mn/Si < 0.015), whereas extraframework manganese is more active at higher loadings (Mn/Si > 0.015).
Keywords:MnS-1 Nanocrystals, Mn XANES, EXAFS, zeolites, microwave-assisted hydrothermal synthesis
Year of publishing:2019
Number of pages:10
Numbering:1
COBISS_ID:5380603 Link is opened in a new window
URN:URN:SI:UNG:REP:9RGERSDI
DOI:DOI: 10.1021/acs.cgd.8b01181 Link is opened in a new window
Views:300
Downloads:0
Metadata:XML RDF-CHPDL DC-XML DC-RDF
Categories:Document is not linked to any category.
:
  
Average score:(0 votes)
Your score:Voting is allowed only for logged in users.

Hover the mouse pointer over a document title to show the abstract or click on the title to get all document metadata.

Record is a part of a journal

Title:Crystal Growth and Design
Shortened title:Cryst. Growth Des
Publisher:American Chemical Society
ISSN:1528-7483
Year of publishing:2019

Back