The VISIO platform (VIbrationnal Spectroscopies for In situ and Operando) hosted by the LCS provides researchers with spectroscopic tools adapted to understand at the molecular scale how works their catalyst.
The VISIO platform, unique in the world in terms of the number and nature of the equipment, is currently composed of a vast set of UV-, Raman- and infrared spectrometers.
Each spectrometer is at the center of a sophisticated system for the analysis of catalytic materials either under vacuum or static controlled atmosphere for the study of the surface properties of the materials via the adsorption of probe molecules (in situ spectroscopy), or under gas flow for the study of catalysts at operando conditions (simulation of the conditions of the industrial processes).
The VISIO platform is composed of 24 workstations dedicated to the different spectroscopic measurements. A schematic view of the platform is reported below with a picture of one of the IR operando spectroscopy workstations. In detail, the different stations are of four types:
- 13 “in situ IR” stations dedicated to qualitative and quantitative measurements of surface properties of materials (acidity, basicity, redox, atomic composition, metal dispersion, confinement, …) via the controlled adsorption of probe molecules.
Some of these stations have specificities:
- 3 “IR in situ flow” stations offer the possibility to treat samples under flow either at atmospheric pressure or high pressure (up to 50 bars)
- 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 under conditions of flow, temperature, pressure, … close to the real process. The aim is to reach the reaction mechanisms involved via a better knowledge of the active sites, intermediary and spectator species
- 1 “Raman Microscopy” station dedicated to the measurement of the structural evolution of materials
- 1 “UV-Vis” station dedicated to the measurements of the photochemical properties of the materials (oxidation state, plasmonic band, light absorption)
- 1 Time resolved absorption transient for investigating the life-time of the exited state of a materials and their photolumiscence in nanosecond scale
Five people participate in the management of the platform via a steering committee and have the mission to ensure the proper functioning of all the devices of each station, the management of the use schedules, the training of users and the development of tools. The latter is an important activity because it allows us to propose unique and efficient research tools adapted to the research activities of the LCS and allows the platform to occupy a unique place in the field of spectroscopies applied to the observation of materials in a chemical reactor. Among these accessories, the numerous infrared cells developed have allowed to extend the research fields (photo-catalysis, co-adsorption, plasma, microwave, real catalysts, …). Some of the models have even been acquired by very famous international laboratories.
List of the main equipments :
- 22 FTIR spectrometers equipped with MCT and DTGS detectors including :
- 2 dedicated to fast acquisition in rapid-scan and step-scan mode
- 2 IR microscopes for spatial acquisition
- 8 equipped with an annex bench dedicated to gas analysis
- 1 equipped with elements (IR sources, detectors and separators) for near IR and far IR analysis.
- Opernado, In-situ, and Horizontal reactor cells
- 1 Raman microscope
- 1 UV-Vis spectrometer
- 1 Laser Flash Photolysis
- 1 Cyclic voltametry
- 10 UV and visible monochromatic and polychromatic light sources (LC8 and LED)
- 11 mass spectrometers (0-200 amu)
- 3 photoluminescence analyzers dedicated to NOx analysis
- 1 GC
- 2 GC-compact
- 14 cryostats: 1 x 200/-40°C, 2 x 100/-90°C and 11 x 100/-30°C
- About 40 IR, Raman and UV cells adapted for in situ and operando experiments.
