Combining Time-Resolved Hard X-ray Diffraction and Diffuse Reflectance Infrared Spectroscopy To Illuminate CO Dissociation and Transient Carbon Storage by Supported Pd Nanoparticles during CO/NO Cycling

2010 ◽  
Vol 132 (13) ◽  
pp. 4540-4541 ◽  
Author(s):  
Mark A. Newton ◽  
Marco Di Michiel ◽  
Anna Kubacka ◽  
Marcos Fernández-García
Keyword(s):  
Infrared Spectroscopy ◽  
Diffuse Reflectance ◽  
Pd Nanoparticles ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Co Dissociation ◽  
Diffuse Reflectance Infrared Spectroscopy ◽  
Diffuse Reflectance Infrared ◽  
Supported Pd

Thermal Evolution of Carbon-Supported Pd Nanoparticles Studied by Time-Resolved X-ray Diffraction

2001 ◽  
Vol 105 (34) ◽  
pp. 8088-8091 ◽  
Author(s):  
Patrizia Canton ◽  
Carlo Meneghini ◽  
Pietro Riello ◽  
Antonella Balerna ◽  
Alvise Benedetti
Keyword(s):  
Thermal Evolution ◽  
Pd Nanoparticles ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Supported Pd

scholarly journals Time-resolved operando studies of carbon supported Pd nanoparticles under hydrogenation reactions by X-ray diffraction and absorption

2018 ◽  
Vol 208 ◽  
pp. 187-205 ◽  
Author(s):  
Aram L. Bugaev ◽  
Oleg A. Usoltsev ◽  
Andrea Lazzarini ◽  
Kirill A. Lomachenko ◽  
Alexander A. Guda ◽  
...  
Keyword(s):  
Pd Nanoparticles ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Hydrogenation Reactions ◽  
X Ray Absorption ◽  
Supported Pd ◽  
Comprehensive Study ◽  
Operando Studies

We present a comprehensive study of a 5 wt% Pd/C catalyst in various environments by using in situ and operando X-ray absorption and diffraction.

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.

Figures of Merit for a Diffuse Reflectance Accessory Using an On-Axis Ellipsoidal Collecting Mirror

1988 ◽  
Vol 42 (3) ◽  
pp. 428-433 ◽  
Author(s):  
E. H. Korte
Keyword(s):  
Infrared Spectroscopy ◽  
Noise Level ◽  
Diffuse Reflectance ◽  
Field Of View ◽  
Figures Of Merit ◽  
Size Dependent ◽  
Diffuse Reflectance Infrared Spectroscopy ◽  
Diffuse Reflectance Infrared

The attainable efficiency of an accessory for diffuse reflectance infrared spectroscopy where both the irradiation and detection optics are located on the same side of the sample is analyzed, the size-dependent noise level of the detector being taken into account. The resulting figures of merit are found to reach up to more than 0.3, when standard detectors of 60° field-of-view are considered.

scholarly journals Mechanism and Performance of the SCR of NO with NH3 over Sulfated Sintered Ore Catalyst

Catalysts ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 90 ◽  
Author(s):  
Wangsheng Chen ◽  
Fali Hu ◽  
Linbo Qin ◽  
Jun Han ◽  
Bo Zhao ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Catalytic Reduction ◽  
Nox Reduction ◽  
Space Velocity ◽  
Acid Sites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffuse Reflectance Infrared Spectroscopy ◽  
And Performance ◽  
Diffuse Reflectance Infrared

A sulfated sintered ore catalyst (SSOC) was prepared to improve the denitration performance of the sintered ore catalyst (SOC). The catalysts were characterized by X-ray Fluorescence Spectrometry (XRF), Brunauer–Emmett–Teller (BET) analyzer, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and diffuse reflectance infrared spectroscopy (DRIFTS) to understand the NH3-selective catalytic reduction (SCR) reaction mechanism. Moreover, the denitration performance and stability of SSOC were also investigated. The experimental results indicated that there were more Brønsted acid sites at the surface of SSOC after the treatment by sulfuric acid, which lead to the enhancement of the adsorption capacity of NH3 and NO. Meanwhile, Lewis acid sites were also observed at the SSOC surface. The reaction between −NH2, NH 4 + and NO (E-R mechanism) and the reaction of the coordinated ammonia with the adsorbed NO2 (L-H mechanism) were attributed to NOx reduction. The maximum denitration efficiency over the SSOC, which was about 92%, occurred at 300 °C, with a 1.0 NH3/NO ratio, and 5000 h−1 gas hourly space velocity (GHSV).

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