Skip to Main content Skip to Navigation
Theses

Caractérisation structurale de catalyseurs hétérogènes en conditions de fonctionnement par spectroscopie d'absorption des rayons X résolue dans le temps

Abstract : Heterogeneous catalysts are complex material whose structures can change on working conditions. To tackle new environmental and economic issues a better knowledge of the relationship between catalytic and structural properties is needed. Only in situ time resolved characterisations i.e. in real working conditions can provide this information.In this study we worked with operando time-resolved X-ray Absorption Spectroscopy (XAS) on two types of heterogeneous catalysts: Fischer-Tropsch catalysts and hydrodesulfurisation catalysts. If these catalysts have been known for many years, only few characterisations are conducted in situ or operando during the reaction.Given their reaction conditions (high temperature and high pressure), these characterisations involved first the construction of tools for in situ characterisation of heterogeneous catalysts under high pressure of gas. Then we assembled a coherent set of characterisation techniques around the Fischer-Tropsch catalyst to enable the structural study at different scales: the local order with the Quick-EXAFS and long-range order with the X-ray diffraction. To observe the effect on the catalytic properties of the crystalline form of the active phase, we quantified for the same catalyst its activity by Raman spectroscopy and mass spectrometry after activation by two different treatments Besides, simultaneous characterisation of two metal species, accessible by the QEXAFS setup installed on the SAMBA beamline, allowed an accurate description of the activation process of bimetallic catalysts for hydrodesulfurisation. We focused our study on the comparison of catalysts with the same formulation with different pretreatments (dried / calcined) and two catalysts promoted by different metals: cobalt and nickel.
Document type :
Theses
Complete list of metadatas

https://tel.archives-ouvertes.fr/tel-00756909
Contributor : Abes Star :  Contact
Submitted on : Saturday, November 24, 2012 - 1:02:42 AM
Last modification on : Thursday, November 19, 2020 - 3:16:29 AM
Long-term archiving on: : Monday, February 25, 2013 - 2:45:19 AM

File

VA2_ROCHET_AMELIE_23112011.PDF
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-00756909, version 1

Collections

Citation

Amélie Rochet. Caractérisation structurale de catalyseurs hétérogènes en conditions de fonctionnement par spectroscopie d'absorption des rayons X résolue dans le temps. Autre. Université Paris Sud - Paris XI, 2011. Français. ⟨NNT : 2011PA112247⟩. ⟨tel-00756909⟩

Share

Metrics

Record views

1100

Files downloads

361