In Situ Cobalt Speciation on γ-Al2O3 in the Presence of Carboxylate Ligands in Supported Catalyst Preparation

2017 ◽  
Vol 121 (39) ◽  
pp. 21461-21471 ◽  
Author(s):  
A. Davantès ◽  
C. Schlaup ◽  
X. Carrier ◽  
M. Rivallan ◽  
G. Lefèvre
Keyword(s):  
Supported Catalyst ◽  
Catalyst Preparation ◽  
Carboxylate Ligands

scholarly journals In Situ DRIFTS Investigation on CeOx Catalyst Supported by Fly-Ash-Made Porous Cordierite Ceramics for Low-Temperature NH3-SCR of NOX

Catalysts ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 496 ◽  
Author(s):  
Shaoxin Wang ◽  
Ziwei Chen ◽  
Beini He ◽  
Zheng Yan ◽  
Hao Wang ◽  
...  
Keyword(s):  
Fly Ash ◽  
Low Temperature ◽  
Photoelectron Spectroscopy ◽  
Active Sites ◽  
Supported Catalyst ◽  
Nh3 Scr ◽  
Scr Catalysts ◽  
Cordierite Ceramics ◽  
Porous Cordierite

A series of CeOx catalysts supported by commercial porous cordierite ceramics (CPCC) and synthesized porous cordierite ceramics (SPCC) from fly ash were prepared for selective catalytic reduction of NOx with ammonia (NH3-SCR). A greater than 90% NOx conversion rate was achieved by the SPCC supported catalyst at 250–300 °C when the concentration of loading precursor was 0.6 mol/L (denoted as 0.6Ce/SPCC), which is more advantageous than the CPCC supported ones. The EDS mapping results reveal the existence of evenly distributed impurities on the surface of SPCC, which hence might be able to provide more attachment sites for CeOx particles. Further measurements with temperature programmed reduction by hydrogen (H2-TPR) demonstrate more reducible species on the surface of 0.6Ce/SPCC, thus giving rise to better NH3-SCR performance at a low-temperature range. The X-ray photoelectron spectroscopy (XPS) analyses reveal that the Ce atom ratio is higher in 0.6Ce/SPCC, indicating that a higher concentration of catalytic active sites could be found on the surface of 0.6Ce/SPCC. The in situ diffused reflectance infrared fourier transform spectroscopy (DRIFTS) results indicate that the SCR reactions over 0.6Ce/SPCC follow both Eley-Rideal (E-R) and Langmuir-Hinshelwood (L-H) mechanisms. Hence, the SPCC might be a promising candidate to provide support for NH3-SCR catalysts, which also provide a valuable approach to recycling the fly ash.

Solvent and in situ catalyst preparation impacts upon Noyori reductions of aryl-chloromethyl ketones: application to syntheses of chiral 2-amino-1-aryl-ethanols

2006 ◽  
Vol 17 (14) ◽  
pp. 2154-2182 ◽  
Author(s):  
Steven P. Tanis ◽  
Bruce R. Evans ◽  
James A. Nieman ◽  
Timothy T. Parker ◽  
Wendy D. Taylor ◽  
...  
Keyword(s):  
Catalyst Preparation

scholarly journals A β-Carbon elimination strategy for convenient in situ access to cyclopentadienyl metal complexes

2017 ◽  
Vol 8 (10) ◽  
pp. 7174-7179 ◽  
Author(s):  
G. Smits ◽  
B. Audic ◽  
M. D. Wodrich ◽  
C. Corminboeuf ◽  
N. Cramer
Keyword(s):  
Metal Complexes ◽  
Catalyst Preparation ◽  
Metal Salts ◽  
Cyclopentadienyl Metal

Stable pre-ligands and common metal salts provide,viaβ-carbon elimination, access to Cp-metal complexes suitable forin situcatalyst preparation.

Infrared Spectra of Some Nonreduced Methanation Catalysts

1978 ◽  
Vol 32 (5) ◽  
pp. 496-499 ◽  
Author(s):  
Eugene B. Bradley ◽  
John M. Stencel
Keyword(s):  
Infrared Spectra ◽  
Linear Chain ◽  
Spectral Characteristics ◽  
Catalyst Preparation ◽  
Silica Support ◽  
Alumina Support ◽  
Commercial Use ◽  
Silicate Structure ◽  
Catalyst Pellets

The infrared spectra (4000 to 400 cm−1) of two commercial nonreduced methanation catalysts have been recorded and interpreted. The catalysts are prepared as mixtures of (a) nickel in a silica support and (b) nickel in an alumina support. Graphite is added to these mixtures as a binder to facilitate pressing of catalyst pellets for commercial use. It is revealed in the spectra of the catalysts that although (a) is prepared to have a simple NiO/SiO2 composition the silica support is not of the form SiO2; rather the spectral characteristics are similar to those found for linear chain silicates. In (b) the Al—O vibrations are characteristic of amorphous Al2O3, and H2O is tightly bound in the pellet. The CO3= ion is present in both (a) and (b). It is not bound to Ni in either (a) or (b), but it is bound in the silicate structure of (a) and associated with Al in (b). The presence of the ion cannot be explained by only in situ generation from atmospheric CO2 and H2O, but its presence must be due to residual CO3= from the catalyst preparation.

scholarly journals Exploiting enhanced paramagnetic NMR relaxation for monitoring catalyst preparation using T1–T2 NMR correlation maps

2019 ◽  
Vol 4 (2) ◽  
pp. 268-272 ◽  
Author(s):  
Carmine D'Agostino ◽  
Pierre Bräuer
Keyword(s):  
Relaxation Times ◽  
Supported Catalyst ◽  
Nmr Relaxation ◽  
Catalyst Preparation ◽  
New Method ◽  
Paramagnetic Nmr ◽  
Surface Sites ◽  
Nmr Relaxation Times ◽  
Paramagnetic Ions

A new method to characterise the evolution of surface sites during metal-supported catalyst preparation has been developed, which exploits NMR relaxation times and their sensitivity to paramagnetic ions.

Effect of Modification Techniques on Surface of Carbon Nanofiber as Catalyst Support

2014 ◽  
Vol 625 ◽  
pp. 345-348
Author(s):  
Nguyen van Thien Duc ◽  
Suriati Sufian ◽  
Nurlidia Mansor ◽  
Noorhana Yahya
Keyword(s):  
Carbon Nanofiber ◽  
Catalyst Support ◽  
Supported Catalyst ◽  
Textural Properties ◽  
Treatment Method ◽  
Catalyst Preparation ◽  
Thermal Method ◽  
Acid Base ◽  
Transmission Electron ◽  
Surface Changes

The intrinsic surface of carbon nanofiber (CNF) is important for supported catalyst preparation. The surface changes due to various techniques applied such as N2thermal and HNO3oxidation methods. The combination of different analyses is to observe the internal structure through Raman spectroscope, textural properties via N2physisorption and morphology of CNF using transmission electron microscope or through quantification of oxygen containing groups by acid base titration. As results, an extension of residence time increases the amount of amorphous and damages the structure of mesoporous CNF texture unexpectedly. The change from hydrophobic to hydrophilic surface of CNF is due to the growing number of oxygen. The surface area of CNF by HNO3treatment method produces 115.14m2/g which is higher than that of using thermal method.

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