Au/Rutile Catalysts: Effect of the Activation Air Flux on the Catalytic Activity for CO Oxidation and the Gold Crystallite Size

2008 ◽  
Vol 112 (32) ◽  
pp. 12463-12467 ◽  
Author(s):  
Xim Bokhimi ◽  
Rodolfo Zanella ◽  
Antonio Morales
Keyword(s):  
Catalytic Activity ◽  
Co Oxidation ◽  
Crystallite Size

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.

scholarly journals CO Oxidation Efficiency and Hysteresis Behavior over Mesoporous Pd/SiO2 Catalyst

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 131 ◽  
Author(s):  
Rola Mohammad Al Soubaihi ◽  
Khaled Mohammad Saoud ◽  
Myo Tay Zar Myint ◽  
Mats A. Göthelid ◽  
Joydeep Dutta
Keyword(s):  
Carbon Monoxide ◽  
Catalytic Activity ◽  
Co Oxidation ◽  
Active Sites ◽  
Bond Activation ◽  
Dissociative Adsorption ◽  
High Catalytic Activity ◽  
Good Catalytic Activity ◽  
Pretreatment Conditions ◽  
Oxidation Efficiency

Carbon monoxide (CO) oxidation is considered an important reaction in heterogeneous industrial catalysis and has been extensively studied. Pd supported on SiO2 aerogel catalysts exhibit good catalytic activity toward this reaction owing to their CO bond activation capability and thermal stability. Pd/SiO2 catalysts were investigated using carbon monoxide (CO) oxidation as a model reaction. The catalyst becomes active, and the conversion increases after the temperature reaches the ignition temperature (Tig). A normal hysteresis in carbon monoxide (CO) oxidation has been observed, where the catalysts continue to exhibit high catalytic activity (CO conversion remains at 100%) during the extinction even at temperatures lower than Tig. The catalyst was characterized using BET, TEM, XPS, TGA-DSC, and FTIR. In this work, the influence of pretreatment conditions and stability of the active sites on the catalytic activity and hysteresis is presented. The CO oxidation on the Pd/SiO2 catalyst has been attributed to the dissociative adsorption of molecular oxygen and the activation of the C-O bond, followed by diffusion of adsorbates at Tig to form CO2. Whereas, the hysteresis has been explained by the enhanced stability of the active site caused by thermal effects, pretreatment conditions, Pd-SiO2 support interaction, and PdO formation and decomposition.

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.

CO Oxidation on Inverse CeOx/Cu(111) Catalysts: High Catalytic Activity and Ceria-Promoted Dissociation of O2

2011 ◽  
Vol 133 (10) ◽  
pp. 3444-3451 ◽  
Author(s):  
Fan Yang ◽  
Jesús Graciani ◽  
Jaime Evans ◽  
Ping Liu ◽  
Jan Hrbek ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Co Oxidation ◽  
High Catalytic Activity

Effect of Impurity and Pretreatment Conditions on the Catalytic Activity of Au Powder for CO Oxidation

2004 ◽  
Vol 97 (3/4) ◽  
pp. 203-208 ◽  
Author(s):  
Yasuo Iizuka ◽  
Aya Kawamoto ◽  
Kazuhiro Akita ◽  
Masakazu Daté ◽  
Susumu Tsubota ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Co Oxidation ◽  
Pretreatment Conditions

Synthesis and characterization of new isostructural series LnFe0.5Sb1.5O6 (Ln = La-Sm) exhibiting high catalytic activity in CO oxidation

2019 ◽  
Vol 777 ◽  
pp. 655-662 ◽  
Author(s):  
A.V. Egorysheva ◽  
O.G. Ellert ◽  
E. Yu Liberman ◽  
D.I. Kirdyankin ◽  
S.V. Golodukhina ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Co Oxidation ◽  
Synthesis And Characterization ◽  
High Catalytic Activity

Improved activity and stability of dealloyed bimodal nanoporous PtCo catalysts for CO oxidation

RSC Advances ◽  
2016 ◽  
Vol 6 (42) ◽  
pp. 35340-35347 ◽  
Author(s):  
Dongwei Li ◽  
Hui Wang ◽  
Chunying Shi ◽  
Xiaohong Xu
Keyword(s):  
Catalytic Activity ◽  
Co Oxidation ◽  
Ptco Alloy

An unsupported dealloyed bimodal nanoporous PtCo alloy exhibited significantly improved catalytic activity and stability for CO oxidation.

Effects of precipitants and surfactants on catalytic activity of Pd/CeO2 for CO oxidation

2017 ◽  
Vol 43 (11) ◽  
pp. 6187-6205
Author(s):  
Yue Zhou ◽  
Xin Liu ◽  
Qiulin Zhang ◽  
Qixian Liu ◽  
Zhongxian Song ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Co Oxidation
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