Optimum Balance of Cu+ and Oxygen Vacancies of CuO x -CeO2 Composites for CO Oxidation Based on Thermal Treatment

2019 ◽  
Vol 2019 (13) ◽  
pp. 1714-1723 ◽  
Author(s):  
Baolin Liu ◽  
Yizhao Li ◽  
Yali Cao ◽  
Lei Wang ◽  
Shaojun Qing ◽  
...  
Keyword(s):  
Thermal Treatment ◽  
Co Oxidation ◽  
Oxygen Vacancies ◽  
Optimum Balance

scholarly journals On the Effects of Doping on the Catalytic Performance of (La,Sr)CoO3. A DFT Study of CO Oxidation

Catalysts ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 312 ◽  
Author(s):  
Antonella Glisenti ◽  
Andrea Vittadini
Keyword(s):  
Catalytic Activity ◽  
Co Oxidation ◽  
Density Functional Calculations ◽  
Density Functional ◽  
Formation Energy ◽  
Oxygen Vacancies ◽  
Catalytic Performance ◽  
Energy Profiles ◽  
High Concentrations ◽  
3D Impurities

The effects of modifying the composition of LaCoO3 on the catalytic activity are predicted by density functional calculations. Partially replacing La by Sr ions has benefical effects, causing a lowering of the formation energy of O vacancies. In contrast to that, doping at the Co site is less effective, as only 3d impurities heavier than Co are able to stabilize vacancies at high concentrations. The comparison of the energy profiles for CO oxidation of undoped and of Ni-, Cu-m and Zn-doped (La,Sr)CoO3(100) surface shows that Cu is most effective. However, the effects are less spectacular than in the SrTiO3 case, due to the different energetics for the formation of oxygen vacancies in the two hosts.

Remarkable Activity of Nanoarchitectonics Mesoporous CuO/CeO2–TiO2 Prepared by Nanocasting and Deposition Precipitation Techniques

2020 ◽  
Vol 20 (5) ◽  
pp. 2791-2802
Author(s):  
Duangamol Ongmali ◽  
Sakollapath Pithakratanayothin ◽  
Sureerat Jampa ◽  
Apanee Luengnaruemitrchai ◽  
Thanyalak Chaisuwan ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Catalytic Activity ◽  
Co Oxidation ◽  
Crystallite Size ◽  
Oxygen Vacancies ◽  
Redox Properties ◽  
Oxygen Defect ◽  
Nitrate Salt ◽  
Hard Template ◽  
Different Levels

In this work, a ceria (CeO2) support was modified with titania (TiO2) by nanocasting using MCM-48 as a hard template and then loading Cu (as the nitrate salt) at different levels (3–9% by weight) by deposition-precipitation followed by calcination. The addition of TiO2 in MSP CeO2 revealed that the MSP CeO2 was significantly improved the oxygen vacancies of the catalyst by increasing the Ce3+ content from 38 to 75% and stabilizing the Ce3+ species by bonding with the oxygen as Ce(4f)-O(2p)-Ti(3d). Moreover, the bonding of MSP CeO2 with TiO2 generated the oxygen defect vacancies (s–Ti3+), allowing Cu2+ to occupy and be reduced to Cu+ during calcination. The smaller CeO2 crystallite size (2.7 nm) of 9Cu/CeO2–TiO2 increased the mass-specific CO-Oxidation, showing the best catalytic activity due to its highest redox properties, as determined by H2-TPR and also showing resistant property to water and carbon dioxide. Indeed, water was adsorbed on the Ce3+ sites, generating OHads which reacted with CO to form –COOH, resulting in CO2.

Physicochemical characterization and catalytic CO oxidation performance of nanocrystalline Ce–Fe mixed oxides

RSC Advances ◽  
2014 ◽  
Vol 4 (22) ◽  
pp. 11322-11330 ◽  
Author(s):  
Putla Sudarsanam ◽  
Baithy Mallesham ◽  
D. Naga Durgasri ◽  
Benjaram M. Reddy
Keyword(s):  
Co Oxidation ◽  
Oxygen Vacancies ◽  
Lattice Strain ◽  
Mixed Oxides ◽  
Physicochemical Characterization ◽  
Oxidation Activity ◽  
Catalytic Co Oxidation ◽  
Nano Oxide ◽  
Oxidation Performance

Fe-doped CeO2 nano-oxide exhibited superior CO oxidation activity compared to pristine CeO2 due to its facile reducible nature, enhanced lattice strain, and ample oxygen vacancies.

Investigation of oxygen vacancies on Pt- or Au-modified CeO2 materials for CO oxidation

RSC Advances ◽  
2016 ◽  
Vol 6 (74) ◽  
pp. 70653-70659 ◽  
Author(s):  
Yanjie Zhang ◽  
Yanyan Zhao ◽  
Han Zhang ◽  
Liyuan Zhang ◽  
Huipeng Ma ◽  
...  
Keyword(s):  
Co Oxidation ◽  
Oxygen Vacancies ◽  
Precipitation Method ◽  
Oxidation Of Co ◽  
Redox Ability

Metal (Au or Pt)-modified CeO2 materials with excellent redox ability for the oxidation of CO to CO2 were prepared by a redox precipitation method and a certain amount (4.2%) of oxygen vacancies was necessary to improve the CO oxidation on Pt-CeO2.

Surface oxygen vacancies in gold based catalysts for CO oxidation

RSC Advances ◽  
2014 ◽  
Vol 4 (25) ◽  
pp. 13145-13152 ◽  
Author(s):  
F. Romero-Sarria ◽  
J. J. Plata ◽  
O. H. Laguna ◽  
A. M. Márquez ◽  
M. A. Centeno ◽  
...  
Keyword(s):  
Co Oxidation ◽  
Oxygen Vacancies ◽  
Surface Oxygen

CO oxidation on single and multilayer Pd oxides on Pd(111): mechanistic insights from RAIRS

2014 ◽  
Vol 4 (11) ◽  
pp. 3826-3834 ◽  
Author(s):  
Feng Zhang ◽  
Tao Li ◽  
Li Pan ◽  
Aravind Asthagiri ◽  
Jason F. Weaver
Keyword(s):  
Co Oxidation ◽  
Oxygen Vacancies ◽  
Strong Binding

Strong binding on oxygen vacancies and metallic domains promotes CO oxidation on partially-reduced PdO(101), while adsorption only on metallic sites promotes CO oxidation when 2D oxide coexists with Pd(111).

The influence of ceria on Cu/TiO2 catalysts to produce abundant oxygen vacancies and induce highly efficient CO oxidation

2020 ◽  
Vol 10 (13) ◽  
pp. 4271-4281 ◽  
Author(s):  
Ching-Shiun Chen ◽  
Tse-Ching Chen ◽  
Hung-Chi Wu ◽  
Jia-Huang Wu ◽  
Jyh-Fu Lee
Keyword(s):  
Activation Energy ◽  
Co Oxidation ◽  
Oxygen Vacancies ◽  
Turnover Frequency ◽  
Highly Efficient ◽  
Frequency Rate ◽  
Lower Activation ◽  
Lower Activation Energy

Ce and Cu species deposited on TiO2 can apparently provide a higher turnover frequency rate and lower activation energy than the Cu/TiO2 catalyst and the Ce and Cu species on SiO2 catalysts.

Cathodoluminescence Quenching in Yb-Doped ZnO Nanostructures

2009 ◽  
Vol 5 ◽  
pp. 177-183 ◽  
Author(s):  
A. Susarrey-Arce ◽  
M. Herrera-Zaldívar ◽  
W. de la Cruz ◽  
Umapada Pal
Keyword(s):  
Energy Transfer ◽  
Thermal Treatment ◽  
Point Defects ◽  
Chemical Method ◽  
Oxygen Vacancies ◽  
Energy Transfer Process ◽  
Physical Method ◽  
Zno Nanostructures ◽  
Physical Methods ◽  
Doped Zno

Cathodoluminescence (CL) quenching was observed in ZnO nanostructures when doped with Yb by both chemical and physical methods. CL spectra of the samples revealed a defect emission at 2.25 eV in samples prepared by the chemical method, and an emission at 2.5 eV in samples prepared by the physical method. From the thermal treatment studies, it was found that oxygen vacancies are responsible for the 2.5 eV emission. Observed CL quenching in ZnO is explained through the participation of point defects in the energy transfer process from ZnO to Yb3+.

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