Genesis of a Cerium Oxide Supported Gold Catalyst for CO Oxidation: Transformation of Mononuclear Gold Complexes into Clusters as Characterized by X-Ray Absorption Spectroscopy

2009 ◽  
Vol 113 (8) ◽  
pp. 3259-3269 ◽  
Author(s):  
Veronica Aguilar-Guerrero ◽  
Rodrigo J. Lobo-Lapidus ◽  
Bruce C. Gates
Keyword(s):  
Co Oxidation ◽  
Cerium Oxide ◽  
Absorption Spectroscopy ◽  
Gold Catalyst ◽  
Gold Complexes ◽  
X Ray ◽  
Supported Gold ◽  
X Ray Absorption

The Relative Merits of Oxides of Hafnium, Cerium and Thorium as Surrogates for Plutonium Oxide in Calcium Phosphate Ceramics

2009 ◽  
Vol 1193 ◽  
Author(s):  
B. L. Metcalfe ◽  
S. K. Fong ◽  
L. A. Gerrard ◽  
I. W. Donald ◽  
E. S. Welch ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Calcination Temperature ◽  
Cerium Oxide ◽  
Absorption Spectroscopy ◽  
Hafnium Oxide ◽  
Intermediate Level ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Absorption ◽  
Additional Phase

AbstractThe choice of surrogate for plutonium oxide for use during the initial stages of research into the immobilization of intermediate level pyrochemical wastes containing plutonium andamericium oxides in a calcium phosphate host has been investigated by powder X-ray diffraction and X-ray absorption spectroscopy. Two non-radioactive surrogates, hafnium oxide and cerium oxide, together with radioactive thorium oxide were compared. Similarities in behaviour were observed for all three surrogates when calcined at the lowest temperature, 750°C but differences became more pronounced as the calcination temperature was increased to 950°C. Although some reaction occurred between all the surrogates and the host to form a substituted whitlockite phase, increasing the temperature led to a significant increase in the cerium reaction and the formation of an additional phase, monazite. Additionally it was observed that the cerium became increasingly trivalent at higher temperatures.

scholarly journals The Study of Nanocrystalline Cerium Oxide by X-Ray Absorption Spectroscopy

2000 ◽  
Vol 149 (2) ◽  
pp. 408-413 ◽  
Author(s):  
Ponnusamy Nachimuthu ◽  
Wen-Chen Shih ◽  
Ru-Shi Liu ◽  
Ling-Yun Jang ◽  
Jin-Ming Chen
Keyword(s):  
Cerium Oxide ◽  
Absorption Spectroscopy ◽  
X Ray ◽  
X Ray Absorption

Operando spatially and time-resolved X-ray absorption spectroscopy and infrared thermography during oscillatory CO oxidation

2015 ◽  
Vol 328 ◽  
pp. 216-224 ◽  
Author(s):  
Andreas M. Gänzler ◽  
Maria Casapu ◽  
Alexey Boubnov ◽  
Oliver Müller ◽  
Sabrina Conrad ◽  
...  
Keyword(s):  
Co Oxidation ◽  
Infrared Thermography ◽  
Absorption Spectroscopy ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Absorption

Operando X-ray Absorption Spectroscopy Study During Conditioning of Pt-Based Catalysts and Its Implications for CO Oxidation

2020 ◽  
Vol 124 (37) ◽  
pp. 20090-20100
Author(s):  
Andreas M. Gänzler ◽  
Benjamin Betz ◽  
Sina Baier-Stegmaier ◽  
Stéphanie Belin ◽  
Valérie Briois ◽  
...  
Keyword(s):  
Co Oxidation ◽  
Absorption Spectroscopy ◽  
Spectroscopy Study ◽  
X Ray ◽  
X Ray Absorption

scholarly journals Effect of Nickel Oxide Doping to Ceria-Supported Gold Catalyst for CO Oxidation and Water-Gas Shift Reactions

Catalysts ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 584 ◽  
Author(s):  
Miao Shu ◽  
Shuai Wei ◽  
Chun-Jiang Jia ◽  
Dao-Lei Wang ◽  
Rui Si
Keyword(s):  
Nickel Oxide ◽  
Co Oxidation ◽  
Gold Catalyst ◽  
Water Gas Shift ◽  
Precipitation Method ◽  
X Ray ◽  
Co Oxidation Reaction ◽  
Metal Metal ◽  
Supported Gold ◽  
Water Gas

Ceria-supported gold catalyst has drew much research interest owing to its high reactivity on CO oxidation and water-gas shift (WGS) reactions. However, till now, there were relatively limited studies on the effect of secondary metal/metal oxide component into gold-ceria system to enhance its catalytic performance. In this work, we synthetized the ceria supported gold-nickel samples via a deposition-precipitation method with the base of NaHCO3 to adjust final pH value of 8~9. We found that the addition of nickel oxide drove off the gold species from the stock solution during synthesis, and thus resulted in a dramatical decrease on doped Au concentration. No crystallized phases of gold and nickel were observed on the surface of ceria nanorods in both X-ray diffraction (XRD) and transmission electron microscopy (TEM). The valence of nickel was maintained as Ni2+ for all the measured samples by X-ray photoelectron spectroscopy (XPS), while gold was oxidized with the increased nickel amount after analysis of X-ray absorption near edge spectroscopy (XANES). The corresponding catalytic tests showed that with the introduction of nickel oxide, the activity of gold-ceria catalyst was promoted for the WGS reaction, but inhibited for the CO oxidation reaction.

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