Plateau technique

Technical Facilities

The laboratory's research relies on a range of techniques and spectroscopies to synthesize, characterize and test the systems developed by our researchers. These state-of-the-art facilities belong either to the laboratory  or to associated organizations, such as the Fédération de Chimie et Matériaux de Paris-Centre (FCMat).

Please find below a presentation of these, as well as the LRS contacts:

Optical, vibrational and Electronic Spectroscopies Facilities

Contacts : Jean-Marc KRAFFT and Laetitia VALENTIN

Principle - Benefits of the technique

Infrared is a spectroscopic method for analyzing vibration modes, providing information on the molecular structure of materials. By analyzing the modes of vibration of adsorbed probe molecules, this technique can also be used to characterize certain surface properties of materials (acidity, basicity, metallic character, etc.).

The spectroscopic equipment consists of 7 BRUKER SPECTROMETERS (2 Vector 22, 2 Vertex 70, 1 Vertex 80, 1 Tensor II and 1 Invenio) for routine analyses and others more specific to the laboratory's themes.

In situ analysis in transmission mode:

Two spectrometers (1 Vector 22 and 1 Vertex 70) dedicated to in situ analyses enable the monitoring of heat treatments and the characterization of material surface properties (acidity, basicity, coordination mode, metal dispersion, nature of active sites, ...) via the adsorption-desorption of probe molecules (CO, NO, Pyridine, Propyne, Acetylene, N2, labeled molecules, ...).

Spectrometers :
- Vector 22: mid-IR range 370-7500 cm-1; DTGS detector optimum resolution: 1 cm-1
- Vertex 70: mid-IR range 350-8000 cm-1; DTGS and MCT detectors optimum resolution: 0.4 cm-1

Accessories & environment:
- Each spectrometer is equipped with specific cells developed for measurements in transmission mode under controlled atmospheres at RT (Figure a) or at liquid nitrogen temperature (Figure b) after in situ heat treatment of the material (under vacuum or controlled atmosphere).


- Samples in the form of self-supporting pellets are placed on a mobile sample holder, inserted into the IR cell. This sample holder allows the operator to move the sample either in the oven, for thermal treatment, or in the IR beam, for analysis.

- Each measuring cell is connected to a glass manifold (c), enabling its atmosphere to be controlled (vacuum or gas flow treatment, introduction of probe molecules).

  • Selected publications

-    FTIR with probe molecules: Pyridine, CO (low T) & UV spectr.
Sadek, R.;Chalupka-Spiewak, K.; Krafft, J.-M.;Millot, Y.; Valentin, L.; Casale, S.;Gurgul, J.; Dzwigaj, S.
The Synthesis of Different Series of Cobalt BEA Zeolite Catalysts by Post-Synthesis Methods and Their Characterization. Catalysts, 12, 1644, 2022; https://doi.org/10.3390/catal12121644

-    FTIR with proble molecules: Lutidine, CO (Low T) & Raman spectr. & acidity-catalytic activity correlation
Lebarbier V., Houalla M., Onfroy T.
New insight into the development of Brönsted acidity of niobic acid. Catal. Today, 192, 123-129, 2012; https://doi.org/10.1016/j.cattod.2012.02.061

-    FTIR with proble molecules: Pyridine
Armenise S., Costa C., Luing W. S., Ribeiro M. R., Silva J. M., Valentin L., Casale S., Onfroy T., Muñoz M. and Launay F.
Design and evaluation of two approaches for the synthesis of hierarchical micro-/mesoporous catalysts for HDPE Hydrocracking. Microporous Mesoporous Mater., 353, 112605, 2023; https://doi.org/10.1016/j.micromeso.2023.112605

-    FTIR with proble molecules N2 (Low T) & Raman spectr.
Jeffrey T. Miller, Neil M. Schweitzer, Mimoun Aouine, Philippe Vernoux, Abdelmalik Boufar, Juliette Blanchard, Jean-Marc Krafft, Christophe Méthivier, Céline Sayag, Frédéric Ser, Mickaël Sicard, and Cyril Thomas
Successive Strong Electrostatic Adsorptions of [RhCl6]3− on Tungstated-Ceria as an Original Approach to Preserve Rh Clusters From Sintering Under High-Temperature Reduction. J. Phys. Chem. C, 125, 25094−25111, 2021; https://doi.org/10.1021/acs.jpcc.1c07644

-    FTIR with proble molecules: CO (Low T) & NMR
Gairola P., Millot Y., Krafft JM., Averseng F., Launay F., Massiani P., Jolivalt C., Reboul J.
On the importance of combining bulk- and surface-active sites to maximize the catalytic activity of metal–organic frameworks for the oxidative dehydrogenation of alcohols using alkyl hydroperoxides as hydride acceptors. Catalysis Science & Technology; 10, 20, 6935-6947, 2020; https://doi.org/10.1039/D0CY00901F

-    FTIR isotopic exchange; Probe molecules: CO (Low T)
S. Diallo-Garcia, M. Ben Osman, J-M. Krafft, S. Boujday, G. Costentin.
Discrimination of infra red fingerprints of bulk and surface POH and OH of hydroxyapatites. Catalysis Today, 226, 81 - 88, 2014; http://dx.doi.org/10.1016/j.cattod.2013.11.041

In situ/operando analysis:

Two spectrometers are mainly dedicated to the analysis of powders under pre-treatment (in situ) or reaction (operando) conditions:

- Vertex 70: IR range 350-8000 cm-1 or 130-6000 cm-1 (KBr or wide range beamsplitters); DTGS and MCT detectors; optimum resolution: 0.16 cm-1 ; 56 scans/sec at 16 cm-1 or 42 scans/sec at 8 cm-1
- Tensor II: mid-IR range 200-5500 cm-1; MCT detectors; optimum resolution: < 2 cm-1

Dedicated accessories :
- DRIFT cells with reaction chamber
- HTC (High temperature cell) transmission cell

The Bruker Tensor II spectrometer is mobile, enabling it to be coupled with catalytic tests for in situ/operando measurement campaigns. For mechanistic studies, the use of labeled reagents can also be envisaged.

  • Selected publications

-    DRIFT In Situ
L. Lin, D. Cornu, M.M. daou, C. Domingos, V. Herledan, J-M. Krafft, G. Laugel, Y. Millot, H. Lauron-Pernot
Role of Water on the activity of Magnesium Silicate for Transesterification Reactions. ChemCatChem, Volume 9, Issue 12, 2399-2407, 2017; https://doi.org/10.1002/cctc.201700139

-    DRIFT Operando
Ben Osman, M; Krafft, JM; Thomas, C; Yoshioka, T; Kubo, J; Costentin, G.
Importance of the Nature of the Active Acid/Base Pairs of Hydroxyapatite Involved in the Catalytic Transformation of Ethanol to n-Butanol Revealed by Operando DRIFTS. ChemCatChem, Volume11, Issue 6, Pages 1765-1778, 2019; https://doi.org/10.1002/cctc.201801880

Time-resolved measurements at solid-gas and solid-liquid interfaces

Contact: Alberto MEZZETTI

A Bruker Vertex 80 spectrometer is dedicated to time-resolved measurements in transmission or attenuated total reflectance (ATR) mode.

- Vertex 80: IR range 350-8000 cm-1; DTGS and MCT detectors; optimum resolution < 0.2 cm-1; rapid scan: acquisition speed > 110 scans/sec at 16 cm-1

Dedicated accessories :
- Diamond crystal ATR (ATR platinium)

Routine analyses :

- Invenio: mid-IR range 350-8000 cm-1 ; DTGS detectors; optimum resolution: < 0.5 cm-1

Contact : Jean-Marc KRAFFT

Principle - Benefits of the technique

Raman spectroscopy is a scattering spectroscopy. Like IR spectroscopy, it probes the vibrational states of the compound under analysis at the molecular and/or crystalline level. But as the selection rules are different from those of IR spectroscopy, these two spectroscopies are in fact complementary.

Equipment :

Kaiser Optical System, Raman Analyzer RXN1 microprobe equipped with a 785nm laser diode.

Features:
Laser diode: l = 785 nm; Max power: 400 mW
Range 100 to 3450 cm-1 on one acquisition
Resolution 4 cm-1 / 3 pixels
1024x256-pixel CCD detector, Peltier-cooled (-70°C)

Two possible modes:
1) Microraman by coupling the spectrometer to a LEICA microscope
Objective 10X; 50X long working distance; 100X

2) Macro using a remote measuring head (5m fiber optics) which can be equipped with a very long focal length lens (75 mm) or a 10X lens.

In macro mode, the spectrometer is mobile. In this configuration, it can be used for In Situ/Operando measurements on laboratory set-ups (catalytic tests, synthesis stations, etc.) or for coupling with other available characterization techniques (FTIR, Photoluminescence, etc.).

  • Selected publications

-    Raman In Situ & EPR
Sarah Petit, Thomas, Yannick Millot, Frederic Averseng, Dalil Brouri, Jean-Marc Krafft, Stanislaw Dzwigaj, Gwenaelle Rousse, Christel Laberty-Robert and Guylène Costentin.
Synergistic Effect Between Ca4V4O14 and Vanadium-Substituted Hydroxyapatite in the Oxidative Dehydrogenation of Propane. ChemCatChem,13, 3995–400, 2021; https://doi.org/10.1002/cctc.202100807

-    SERS (Surface Enhanced Raman Spectroscopy)
Vincent Pellas, Juliette Blanchard, Clément Guibert, Jean-Marc Krafft, Antoine Miche, Michèle Salmain and Souhir Boujday.
Gold Nanorod Coating with Silica Shells Having Controlled Thickness and Oriented Porosity: Tailoring the Shells for Biosensing. ACS Appl. Nano Mater, 4, 9, 9842–9854, 2021; https://doi.org/10.1021/acsanm.1c02297

-    Raman & fluorescence spectr.
Palierse E., Hélary C., Krafft JM., Génois I., Masse S., Laurent G.,Alvarez Echazu M.I., Selmane M., Casale S., Valentin L., Miche A., Chan B.C.L., Lau C.B.S., Ip M., Desimone M. F., Coradin T., Jolivalt C.
Baicalein-modified hydroxyapatite nanoparticles and coatingswith antibacterial and antioxidant properties. Materials Science & Engineering C; 118, 111537, 2021; https://doi.org/10.1016/j.msec.2020.111537

-    Raman & FTIR probe molecules: N2 (Low T)
Jeffrey T. Miller, Neil M. Schweitzer, Mimoun Aouine, Philippe Vernoux, Abdelmalik Boufar, Juliette Blanchard, Jean-Marc Krafft, Christophe Méthivier, Céline Sayag, Frédéric Ser, Mickaël Sicard, and Cyril Thomas.
Successive Strong Electrostatic Adsorptions of [RhCl6]3− on Tungstated-Ceria as an Original Approach to Preserve Rh Clusters From Sintering Under High-Temperature Reduction. J. Phys. Chem. C, 125, 25094−25111, 2021 ; https://doi.org/10.1021/acs.jpcc.1c07644

Contacts : Josefine SCHNEE and Frédéric AVERSENG

Principle - Benefits of the technique

This spectroscopy records electronic absorption spectra of compounds in solution (transmission) or in solid form (reflection), and identifies the electronic configuration of the element in question, if it's a metal, as well as its environment (number and nature of ligands, symmetry of the complex), by means of the number of bands and their position.

The near-infrared section provides complementary information to that gathered by infrared spectroscopy, in terms of bond vibrations (harmonic bands of IR bands, or combinations). Using the mantis equipment, it is also possible to work in reflection on a solid placed in an environmental cell, subjected to heat treatments and/or changes in gaseous atmosphere.

Equipment:

Cary 5000 (Varian) equipped with a 150 mm external sphere for acquisition of diffuse reflection spectra on powders, over a 190-2500 nm range.

In addition to conventional equipment for working in transmission or with a mantis cell/environmental cell device (temperature, gas atmosphere or vacuum treatments).

Exemple:

As you can see in the picture below, the shift in bands towards longer wavelengths is due to the weaker ligand field created by the oxide ions on an alumina surface, compared with that created by the nitrogen atoms in ethylenediamine.

Above: Evolution of the [Ni(en)3]2+ complex deposited on alumina and heated under helium; evidence of progressive grafting of the complex to [Ni(en)2(OAl)2].

Contact : Frédéric AVERSENG

Principle - Benefits of this technique

Electron paramagnetic resonance (EPR or Electron Spin Resonance ESR) is a spectroscopy very similar in concept to NMR. It can be used to identify and study paramagnetic species (with unpaired electrons) present in liquid, solid or gaseous media. It is typically used to detect and/or characterize organic radicals, transition metal complexes/ions, point defects in solids or conduction electrons. The very high sensitivity of this technique is in the ppm range.

In the case of transition ions/complexes supported on oxides, the spectra obtained can be used to determine the degree of oxidation, the number of ligands, the symmetry, the position (surface or core) and the dispersion of these paramagnetic species, providing a better understanding of the activity of heterogeneous catalysts.

In addition to these qualitative characterizations, EPR can also be used quantitatively in liquids (e.g. production of hydroxyl radicals by Fenton reaction) or pseudo-quantitatively for solids (e.g. creation/disappearance of defects during chemical/thermal treatments).

In addition, temporal EPR monitoring can be used to characterize the appearance/disappearance kinetics of paramagnetic species (e.g. species stability, photochemical reactions, ...).