scholarly journals Atomic‐Scale Insights into the Low‐Temperature Oxidation of Methanol over a Single‐Atom Pt 1 ‐Co 3 O 4 Catalyst

2019 ◽  
Vol 29 (31) ◽  
pp. 1902041 ◽  
Author(s):  
Zeyu Jiang ◽  
Xiangbo Feng ◽  
Jianlin Deng ◽  
Chi He ◽  
Mark Douthwaite ◽  
...  
Keyword(s):  
Low Temperature ◽  
Atomic Scale ◽  
Single Atom ◽  
Low Temperature Oxidation ◽  
Temperature Oxidation ◽  
Oxidation Of Methanol

scholarly journals Low-Temperature Oxidation of Methanol to Formaldehyde on a Model Single-Atom Catalyst: Pd Atoms on Fe3O4(001)

ACS Catalysis ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 10977-10982 ◽  
Author(s):  
Matthew D. Marcinkowski ◽  
Simuck F. Yuk ◽  
Nassar Doudin ◽  
R. Scott Smith ◽  
Manh-Thuong Nguyen ◽  
...  
Keyword(s):  
Low Temperature ◽  
Single Atom ◽  
Low Temperature Oxidation ◽  
Temperature Oxidation ◽  
Oxidation Of Methanol

Neutron Diffraction Study of the Structural Changes Occurring During the Low Temperature Oxidation of UO2

2009 ◽  
Vol 1215 ◽  
Author(s):  
Gianguido Baldinozzi ◽  
Lionel Desgranges ◽  
Gurvan Rousseau
Keyword(s):  
Low Temperature ◽  
Neutron Diffraction ◽  
Uranium Dioxide ◽  
Oxidation Process ◽  
Structural Parameters ◽  
Atomic Scale ◽  
Uranium Oxides ◽  
Low Temperature Oxidation ◽  
Temperature Oxidation ◽  
Diffraction Patterns

AbstractThe oxidation of uranium dioxide has been studied for more than 50 years. It was first studied for fuel fabrication purposes and then later on for safety reasons to design a dry storage facility for spent nuclear fuel that could last several hundred years. Therefore, understanding the changes occurring during the oxidation process is essential, and a sound prediction of the behavior of uranium oxides requires the accurate description of the elementary mechanisms on an atomic scale. Only the models based on elementary mechanisms should provide a reliable extrapolation of laboratory results over timeframes spanning several centuries. The oxidation mechanism of uranium oxides requires understanding the structural parameters of all the phases observed during the process. Uranium dioxide crystal structure undergoes several modifications during the low temperature oxidation that transforms UO2 into U3O8. The symmetries and the structural parameters of UO2, β-U4O9, β-U3O7 and U3O8 were determined by refining neutron diffraction patterns on pure single-phase samples. Neutron diffraction patterns, collected during the in situ oxidation of powder samples at 483 K were also analyzed performing Rietveld refinements. The lattice parameters and relative ratios of the four pure phases were measured during the progression of the isothermal oxidation. The transformation of UO2 into U3O8 involves a complex modification of the oxygen sublattice and the onset of complex superstructures for U4O9 and U3O7, associated with regular stacks of complex defects known as cuboctahedra which consist of 13 oxygen interstitial atoms. The structural modifications during the oxidation process are discussed.

Sign in / Sign up

Export Citation Format

Share Document