Vibrational Spectroscopies for In situ and Operando
The VISIO (VIbrationnal Spectroscopies for In situ and Operando) platform hosted by the LCS provides all researchers with the spectroscopic tools they need to understand, at the molecular level, how catalysts work.
The VISIO platform, which is unique in the world in terms of the number and nature of its instruments, currently comprises a vast array of 24 UV, Raman and infrared spectrometers.
Each spectrometer is at the heart of a sophisticated system for analyzing catalytic materials, either under vacuum to study the surface properties of materials by adsorption of probe molecules (in situ method), or under gas flow to study catalysts under operando conditions (simulation of real industrial process conditions).
The VISIO platform comprises 24 workstations dedicated to different spectroscopic measurements. A schematic view of the platform is shown below, with an inset photo of one of the IR operando spectroscopy workstations. In detail, the various items are of four types:
- 13 “IR in situ” stations dedicated to qualitative and quantitative measurements of the surface properties of materials (acidity, basicity, redox, atomic composition, metal dispersion, confinement, etc.) via the controlled adsorption of probe molecules.
Some of these stations have special features:
- 3 “IR in situ sous flux” stations offer the possibility of pretreating samples under flux either at atmospheric pressure or at high pressure (P < 50 bar),
- 2 “IR step-scan” stations for high temporal resolution experiments,
- 2 “IR Microscopy” stations for high spatial resolution experiments.
- 9 “IR operando” stations dedicated to the study of materials in operation under conditions of flow, temperature, pressure, etc. close to the real process. The aim is to get to the bottom of the reaction mechanisms involved by gaining a better understanding of the active sites, intermediates and spectator species.
- 1 “Raman Microscopy” station dedicated to measuring structural changes in materials.
- 1 “UV-Vis” station dedicated to measuring the structure of materials and adsorbed species.
- 22 FTIR spectrometers equipped with MCT and DTGS detectors, including :
- 2 dedicated to rapid step-scan acquisition
- 2 IR microscopes for spatial acquisition
- 8 equipped with an auxiliary bench dedicated to gas analysis
- 1 equipped with elements (IR sources, detectors and separators) for near-IR and far-IR analysis.
- 1 Raman microscope
- 1 UV-Vis spectrometer
- 11 mass spectrometers (0-200 amu)
- 3 photoluminescence analyzers dedicated to NOx analysis
- 1 GC
- 1 microGC
- 14 cryostats : 1 x 200/-40°C, 2 x 100/-90°C et 11 x 100/-30°C
- Some forty IR, Raman and UV cells adapted for in situ and operando experiments.
In Situ Infrared
Operando Infrared
In Situ Infrared
Definition: “In situ” infrared spectroscopy enables qualitative and quantitative evaluation of catalyst surface properties (acidity, basicity, redox, composition, metal dispersion, etc.) by adsorption of specific probe molecules (CO, Pyridine, CH3OH, CH3CN, CO2, Propyne, etc.).
Operando Infrared
Definition: “Operando” infrared spectroscopy enables us to study the catalyst in operation under reaction flow, using operating conditions that are very close to reality.