Related Experiment Video
Updated: Aug 10, 2026

Synthesis of Metal Nanoparticles Supported on Carbon Nanotube with Doped Co and N Atoms and its Catalytic Applications in Hydrogen Production
Published on: December 6, 2021
Spectroscopic characterization of cobalt-containing mesoporous materials
Torbjørn Vrålstad1, Wilhelm R Glomm, Magnus Rønning
1Ugelstad Laboratory, Department of Chemical Engineering, Norwegian University of Science and Technology (NTNU), N-7491 Trondheim, Norway. torbjorn.vralstad@chemeng.ntnu.no
Characterizing cobalt-containing mesoporous materials reveals extended X-ray absorption fine structure spectroscopy (EXAFS) as ideal for verifying cobalt incorporation. This method distinguishes surface-bound from framework cobalt, unlike UV-visible spectroscopy.
Area of Science:
- Materials Science
- Nanotechnology
- Catalysis
Background:
- Cobalt-containing mesoporous materials are synthesized via various methods.
- Understanding cobalt's local environment and properties is crucial for material applications.
Purpose of the Study:
- To comparatively characterize cobalt-containing mesoporous materials prepared using different procedures.
- To gain insights into the local environment and properties of cobalt within these materials.
- To evaluate the suitability of various spectroscopic techniques for analyzing cobalt incorporation.
Main Methods:
- Comparative characterization using transmission electron microscopy/energy-dispersive X-ray spectroscopy (TEM/EDS).
- Extended X-ray absorption fine structure spectroscopy (EXAFS).
- X-ray absorption near edge spectroscopy (XANES).
- Ultraviolet-visible (UV-vis), near-infrared (NIR), and mid-infrared (mid-IR) spectroscopies.
Main Results:
- Transmission electron microscopy/energy-dispersive X-ray spectroscopy (TEM/EDS) indicated that tetraethyl orthosilicate (TEOS) may lead to uneven cobalt distribution.
- Extended X-ray absorption fine structure spectroscopy (EXAFS) proved most effective for verifying framework incorporation by identifying silicon as the second-shell backscatterer.
- EXAFS analysis successfully distinguished between surface-bound and framework-incorporated cobalt.
- X-ray absorption near edge spectroscopy (XANES) and UV-visible spectroscopy showed good agreement regarding cobalt coordination symmetry.
- Cobalt within the silica framework creates Lewis acid sites, potentially located at tetrahedral cobalt sites on the surface.
Conclusions:
- Extended X-ray absorption fine structure spectroscopy (EXAFS) is the preferred method for confirming cobalt's incorporation into mesoporous material frameworks.
- The choice of silicon source, such as tetraethyl orthosilicate (TEOS), impacts cobalt distribution.
- Cobalt incorporation influences the material's properties, creating surface Lewis acid sites.
More Related Videos
10:31Detection and Recovery of Palladium, Gold and Cobalt Metals from the Urban Mine Using Novel Sensors/Adsorbents Designated with Nanoscale Wagon-wheel-shaped Pores
Published on: December 6, 2015
08:55Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
Related Concept Videos
Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
Spectroscopy of Carboxylic Acid Derivatives
In the...
UV–Vis Spectroscopy of Conjugated Systems
One of the factors influencing λmax is the extent of conjugation in the...
Properties of Organometallic Compounds
UV–Vis Spectroscopy: Woodward–Fieser Rules
NMR Spectroscopy of Aromatic Compounds