Synthesis, acid properties and catalysis by niobium oxide nanostructured materials
Several forms of niobium oxide were prepared, including nanostructured mesoporous materials, and their acidity properties were comprehensively investigated and compared with commercially available materials. The composites were characterized by a variety of techniques, including XRD, TEM, N2 adsorpt...
Guardado en:
| Publicado: |
2014
|
|---|---|
| Materias: | |
| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_20444753_v4_n9_p3044_LuisaMarin http://hdl.handle.net/20.500.12110/paper_20444753_v4_n9_p3044_LuisaMarin |
| Aporte de: |
| id |
paper:paper_20444753_v4_n9_p3044_LuisaMarin |
|---|---|
| record_format |
dspace |
| spelling |
paper:paper_20444753_v4_n9_p3044_LuisaMarin2023-06-08T16:33:20Z Synthesis, acid properties and catalysis by niobium oxide nanostructured materials Catalysis Fluorescence Mesoporous materials Molecules Nuclear magnetic resonance spectroscopy Surface reactions Synthesis (chemical) Acidity properties Fluorescence imaging In-depth understanding Randomly distributed Ring opening reaction Single-molecule analysis Single-molecule microscopy Solid-state surface Niobium oxide Several forms of niobium oxide were prepared, including nanostructured mesoporous materials, and their acidity properties were comprehensively investigated and compared with commercially available materials. The composites were characterized by a variety of techniques, including XRD, TEM, N2 adsorption and Hammett acid indicator studies. The acidity of the niobium oxide derivatives was also investigated by the ability of the materials to successfully promote the halochromic ring-opening of an oxazine-coumarin probe that was specifically designed for use in fluorescence imaging studies. The ring-opening reaction was easily monitored using UV-visible, fluorescence and NMR spectroscopy. Single molecule microscopy was employed to gain a more in-depth understanding of the niobium oxide acid catalysis pathway. Using this technique, the rate of niobium oxide mediated protonation was estimated to be 1.8 × 10-13 mol m-2 s-1. Single molecule analysis was also used to obtain a detailed map of Brønsted acid sites on the niobium oxide surface. The active sites, located by multiple blinking events, do not seem to be localized on any area of the material, but rather randomly distributed throughout the solid state surface. As the reaction proceeds, the sites with the highest acidity and accessibility are gradually consumed, making the next tier of acid sites available for reaction. The phenomenon was more closely characterized by using time lapsed reactivity maps. © the Partner Organisations 2014. 2014 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_20444753_v4_n9_p3044_LuisaMarin http://hdl.handle.net/20.500.12110/paper_20444753_v4_n9_p3044_LuisaMarin |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Catalysis Fluorescence Mesoporous materials Molecules Nuclear magnetic resonance spectroscopy Surface reactions Synthesis (chemical) Acidity properties Fluorescence imaging In-depth understanding Randomly distributed Ring opening reaction Single-molecule analysis Single-molecule microscopy Solid-state surface Niobium oxide |
| spellingShingle |
Catalysis Fluorescence Mesoporous materials Molecules Nuclear magnetic resonance spectroscopy Surface reactions Synthesis (chemical) Acidity properties Fluorescence imaging In-depth understanding Randomly distributed Ring opening reaction Single-molecule analysis Single-molecule microscopy Solid-state surface Niobium oxide Synthesis, acid properties and catalysis by niobium oxide nanostructured materials |
| topic_facet |
Catalysis Fluorescence Mesoporous materials Molecules Nuclear magnetic resonance spectroscopy Surface reactions Synthesis (chemical) Acidity properties Fluorescence imaging In-depth understanding Randomly distributed Ring opening reaction Single-molecule analysis Single-molecule microscopy Solid-state surface Niobium oxide |
| description |
Several forms of niobium oxide were prepared, including nanostructured mesoporous materials, and their acidity properties were comprehensively investigated and compared with commercially available materials. The composites were characterized by a variety of techniques, including XRD, TEM, N2 adsorption and Hammett acid indicator studies. The acidity of the niobium oxide derivatives was also investigated by the ability of the materials to successfully promote the halochromic ring-opening of an oxazine-coumarin probe that was specifically designed for use in fluorescence imaging studies. The ring-opening reaction was easily monitored using UV-visible, fluorescence and NMR spectroscopy. Single molecule microscopy was employed to gain a more in-depth understanding of the niobium oxide acid catalysis pathway. Using this technique, the rate of niobium oxide mediated protonation was estimated to be 1.8 × 10-13 mol m-2 s-1. Single molecule analysis was also used to obtain a detailed map of Brønsted acid sites on the niobium oxide surface. The active sites, located by multiple blinking events, do not seem to be localized on any area of the material, but rather randomly distributed throughout the solid state surface. As the reaction proceeds, the sites with the highest acidity and accessibility are gradually consumed, making the next tier of acid sites available for reaction. The phenomenon was more closely characterized by using time lapsed reactivity maps. © the Partner Organisations 2014. |
| title |
Synthesis, acid properties and catalysis by niobium oxide nanostructured materials |
| title_short |
Synthesis, acid properties and catalysis by niobium oxide nanostructured materials |
| title_full |
Synthesis, acid properties and catalysis by niobium oxide nanostructured materials |
| title_fullStr |
Synthesis, acid properties and catalysis by niobium oxide nanostructured materials |
| title_full_unstemmed |
Synthesis, acid properties and catalysis by niobium oxide nanostructured materials |
| title_sort |
synthesis, acid properties and catalysis by niobium oxide nanostructured materials |
| publishDate |
2014 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_20444753_v4_n9_p3044_LuisaMarin http://hdl.handle.net/20.500.12110/paper_20444753_v4_n9_p3044_LuisaMarin |
| _version_ |
1768542007980982272 |