scholarly journals Probing Functionalities and Acidity of Calcined Phenylene-Bridged Periodic Mesoporous Organosilicates Using Dynamic Nuclear Polarization NMR, Diffuse Reflectance Infrared Fourier Transform Spectroscopy, and X-ray Photoelectron Spectroscopy

2020 ◽  
Vol 124 (11) ◽  
pp. 6110-6120
Author(s):  
Cyril Pirez ◽  
Hiroki Nagashima ◽  
Franck Dumeignil ◽  
Olivier Lafon
Keyword(s):  
Fourier Transform ◽  
Dynamic Nuclear Polarization ◽  
Photoelectron Spectroscopy ◽  
Nuclear Polarization ◽  
Diffuse Reflectance ◽  
Fourier Transform Spectroscopy ◽  
X Ray ◽  
Diffuse Reflectance Infrared

Study of Surface Wettability Change of Unconsolidated Sand Using Diffuse Reflectance Infrared Fourier Transform Spectroscopy and Thermogravimetric Analysis

2018 ◽  
Vol 72 (4) ◽  
pp. 562-572 ◽  
Author(s):  
Diana Gómora-Herrera ◽  
Juan Navarrete Bolaños ◽  
Irina V. Lijanova ◽  
Octavio Olivares-Xometl ◽  
Natalya V. Likhanova
Keyword(s):  
Fourier Transform ◽  
Thermogravimetric Analysis ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance ◽  
Fourier Transform Spectroscopy ◽  
Surface Groups ◽  
Polar Compound ◽  
X Ray ◽  
Silicon Oil ◽  
Diffuse Reflectance Infrared

The effects exerted by the adsorption of vapors of a non-polar compound (deuterated benzene) and a polar compound (water) on the surface of Ottawa sand and a sample of reservoir sand (Channel), which was previously impregnated with silicon oil or two kinds of surfactants, (2-hydroxyethyl) trimethylammonium oleate (HETAO) and (2-hydroxyethyl)trimethylammonium azelate (HETAA), were studied by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and thermogravimetric analysis (TGA). The surface chemistry of the sandstone rocks was elucidated by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX). Terminal surface groups such as hydroxyls can strongly adsorb molecules that interact with these surface groups (surfactants), resulting in a wettability change. The wettability change effect suffered by the surface after treating it with surfactants was possible to be detected by the DRIFTS technique, wherein it was observed that the surface became more hydrophobic after being treated with silicon oil and HETAO; the surface became more hydrophilic after treating it with HETAA.

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.

Study of corrosion-protected AIN samples by X-ray photoelectron spectroscopy and diffuse reflectance IR Fourier transform spectroscopy

1995 ◽  
Vol 5 (8) ◽  
pp. 1223-1226 ◽  
Author(s):  
Jose J. Benítez ◽  
Miguel A. Centeno ◽  
María J. Capitán ◽  
Jose A. Odriozola ◽  
Bénédicte Viot ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance ◽  
Fourier Transform Spectroscopy ◽  
X Ray

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.

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