scholarly journals Adding diffuse reflectance infrared Fourier transform spectroscopy capability to extended x-ray-absorption fine structure in a new cell to study solid catalysts in combination with a modulation approach

2014 ◽  
Vol 85 (7) ◽  
pp. 074102 ◽  
Author(s):  
Gian Luca Chiarello ◽  
Maarten Nachtegaal ◽  
Valentina Marchionni ◽  
Luca Quaroni ◽  
Davide Ferri
Keyword(s):  
Fourier Transform ◽  
Fine Structure ◽  
Diffuse Reflectance ◽  
Fourier Transform Spectroscopy ◽  
X Ray ◽  
Solid Catalysts ◽  
Absorption Fine ◽  
Diffuse Reflectance Infrared ◽  
X Ray Absorption

scholarly journals Changes of Pd Oxidation State in Pd/Al2O3 Catalysts Using Modulated Excitation DRIFTS

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 116
Author(s):  
Gian Luca Chiarello ◽  
Ye Lu ◽  
Miren Agote-Arán ◽  
Riccardo Pellegrini ◽  
Davide Ferri
Keyword(s):  
Particle Size ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Oxidation State ◽  
Diffuse Reflectance ◽  
X Ray ◽  
Spectral Changes ◽  
Diffuse Reflectance Infrared ◽  
X Ray Absorption ◽  
Reversible Reduction

Infrared spectroscopy is typically not used to establish the oxidation state of metal-based catalysts. In this work, we show that the baseline of spectra collected in diffuse reflectance mode of a series of Pd/Al2O3 samples of increasing Pd content varies significantly and reversibly under alternate pulses of CO or H2 and O2. Moreover, these baseline changes are proportional to the Pd content in Pd/Al2O3 samples exhibiting comparable Pd particle size. Similar measurements by X-ray absorption spectroscopy on a different 2 wt.% Pd/Al2O3 confirm that the baseline changes reflect the reversible reduction-oxidation of Pd. Hence, we demonstrate that changes in oxidation state of metal-based catalysts can be determined using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and that this behavior is part of the spectral changes that are returned by experiments under operando conditions.

XAFS Study on Chlorination of Y2O3 in LiCl-KCl-ZrCl4 Melt

2008 ◽  
Vol 63 (10-11) ◽  
pp. 735-738 ◽  
Author(s):  
Yoshihiro Okamoto ◽  
Tsuyoshi Yaita ◽  
Hideaki Shiwaku ◽  
Shinichi Suzuki
Keyword(s):  
Fourier Transform ◽  
Fine Structure ◽  
Eutectic Mixture ◽  
Peak Shift ◽  
Chlorination Reaction ◽  
X Ray ◽  
Absorption Fine ◽  
The Fourier Transform ◽  
X Ray Absorption ◽  
Eutectic Melt

The chlorination reaction of Y2O3 with ZrCl4 in LiCl-KCl eutectic melt was investigated by X-ray absorption fine structure (XAFS) technique. The chlorination reaction was observed between 773 K and 823 K as the 1st peak shift of the Fourier transform magnitude function |FT(k3χ(k))|. The peak corresponding to the nearest Y3+-Cl− correlation was observed in the XAFS analysis at 823 K as the result of the chlorination. It was confirmed that the mixture melts after the reaction is almost equivalent to a molten 5% YCl3-(LiCl-KCl eutectic) mixture.

An X-ray diffractometer coupled with diffuse reflectance infrared Fourier transform spectroscopy and gas chromatography forin situandin operandocharacterization: an innovative analytical laboratory instrument

2012 ◽  
Vol 46 (1) ◽  
pp. 262-266 ◽  
Author(s):  
Laure Braconnier ◽  
Isabelle Clémençon ◽  
Christèle Legens ◽  
Virginie Moizan ◽  
Fabrice Diehl ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Diffuse Reflectance ◽  
Fourier Transform Spectroscopy ◽  
Material Surface ◽  
X Ray Diffraction ◽  
Reaction Cell ◽  
X Ray ◽  
High Pressure Reaction ◽  
Diffuse Reflectance Infrared ◽  
The Impact

In heterogeneous catalysis, chemical reactions take place at the surface of the material and can be influenced by its structure. To understand better the impact of the material surface and structure on catalytic properties, it is important to characterize them simultaneously. The association of X-ray diffraction and diffuse reflectance infrared Fourier transform spectroscopy, combined in a single dedicated high-temperature and high-pressure reaction cell with an online gas chromatograph, could be the answer to this challenge. For the first time, such an analytical tool has been developed for laboratory applications. The use of this device is illustrated, and it is validated through thein situstudy of the thermal decomposition of calcium oxalate.

In situ spectroscopic investigation of a Pd local structure over Pd/CeO2 and Pd/MnOx–CeO2 during CO oxidation

2017 ◽  
Vol 5 (25) ◽  
pp. 12998-13008 ◽  
Author(s):  
Erdem Sasmaz ◽  
Chao Wang ◽  
Michael J. Lance ◽  
Jochen Lauterbach
Keyword(s):  
Fourier Transform ◽  
Co Oxidation ◽  
Local Structure ◽  
Diffuse Reflectance ◽  
Oxidation Activity ◽  
X Ray ◽  
Low Temperature Co Oxidation ◽  
Diffuse Reflectance Infrared ◽  
X Ray Absorption

In situ X-ray absorption fine structure (XAS) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) experiments were performed to elucidate the effect of the Pd local structure on low temperature CO oxidation activity of Pd/CeO2 and Pd/MnOx–CeO2.

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