Probing surface-sensitive redox properties of VOx/TiO2 catalyst nanoparticles

Nanoscale ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 7266-7272
Author(s):  
Martin Ek ◽  
Logi Arnarson ◽  
Poul Georg Moses ◽  
Søren B. Rasmussen ◽  
Magnus Skoglundh ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Redox Properties ◽  
Catalyst Nanoparticles ◽  
Tio2 Catalyst

Differences in redox properties are measured at individual facets under reaction-like conditions, explaining variations in catalytic activity on the nanoscale.

Templated Synthesis of Pr-Doped Ceria with Improved Micro and Mesoporosity Porosity, Redox Properties and Catalytic Activity

2017 ◽  
Vol 148 (1) ◽  
pp. 258-266 ◽  
Author(s):  
Arantxa Davó-Quiñonero ◽  
Jorge González-Mira ◽  
Dolores Lozano-Castelló ◽  
Agustín Bueno-López
Keyword(s):  
Catalytic Activity ◽  
Redox Properties ◽  
Doped Ceria ◽  
Templated Synthesis

scholarly journals Catalytic Oxidation of Chlorobenzene over Pd-TiO2 /Pd-Ce/TiO2 Catalysts

Catalysts ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 347 ◽  
Author(s):  
Wenjun Liang ◽  
Xiaoyan Du ◽  
Yuxue Zhu ◽  
Sida Ren ◽  
Jian Li
Keyword(s):  
Catalytic Activity ◽  
Catalytic Oxidation ◽  
Calcination Temperature ◽  
Catalyst Activity ◽  
Space Velocity ◽  
Impregnation Method ◽  
Tio2 Catalyst ◽  
Metal Support ◽  
Oxidation Efficiency

A series of Pd-TiO2/Pd-Ce/TiO2 catalysts were prepared by an equal volume impregnation method. The effects of different Pd loadings on the catalytic activity of chlorobenzene (CB) were investigated, and the results showed that the activity of the 0.2%-0.3% Pd/TiO2 catalyst was optimal. The effect of Ce doping enhanced the catalytic activity of the 0.2% Pd-0.5% Ce/TiO2 catalyst. The characterization of the catalysts using BET, TEM, H2-TPR, and O2-TPD showed that the oxidation capacity was enhanced, and the catalytic oxidation efficiency was improved due to the addition of Ce. Ion chromatography and Gas Chromatography-Mass Spectrometer results showed that small amounts of dichlorobenzene (DCB) and trichlorobenzene (TCB) were formed during the decomposition of CB. The results also indicated that the calcination temperature greatly influenced the catalyst activity and a calcination temperature of 550 °C was the best. The concentration of CB affected its decomposition, but gas hourly space velocity had little effect. H2-TPR indicated strong metal–support interactions and increased dispersion of PdO in the presence of Ce. HRTEM data showed PdO with a characteristic spacing of 0.26 nm in both 0.2% Pd /TiO2 and 0.2% Pd-0.5% Ce/TiO2 catalysts. The average sizes of PdO nanoparticles in the 0.2% Pd/TiO2 and 0.2% Pd-0.5% Ce/TiO2 samples were 5.8 and 4.7 nm, respectively. The PdO particles were also deposited on the support and they were separated from each other in both catalysts.

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.

Influence of Gd and Pr doping on the properties of ceria: texture, structure, redox behaviour and reactivity in CH4/H2O reactions in the presence of H2S

2018 ◽  
Vol 8 (5) ◽  
pp. 1333-1348 ◽  
Author(s):  
M. Florea ◽  
G. Postole ◽  
F. Matei-Rutkovska ◽  
A. Urda ◽  
F. Neaţu ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Redox Properties ◽  
Redox Behaviour ◽  
Texture Structure ◽  
Thermal Sintering

Resistance against thermal sintering, redox properties and catalytic activity in SMR over ceria can be tuned by doping/undoping.

Effect of Addition of Ce on the Catalytic Activity of Fe-Mn-O Catalyst for SCR of NOX with NH3

2011 ◽  
Vol 347-353 ◽  
pp. 453-456
Author(s):  
Hai Zhao ◽  
You Ning Xu ◽  
Duo Jiao Guan
Keyword(s):  
Nitric Oxide ◽  
Catalytic Activity ◽  
Analysis Data ◽  
Redox Properties ◽  
Nanosized Particles ◽  
Study Analysis ◽  
Catalytic Activities ◽  
Mn Oxide ◽  
Scr Of No ◽  
Mn Species

Fe-Mn oxide and Ce-doped Fe-Mn oxide nanosized particles were studied on the structural and catalytic activities for SCR. The catalysts were characterized by TEM, TPR and BET study. Analysis data show that the addition of Ce improves the reduction performance of Fe-Mn species. It was found that the Ce promoted samples exhibited much better activities for SCR of nitric oxide with ammonia because of the promotion of the structural and redox properties.

Enhancement of Low-Temperature NH3-SCR Catalytic Activity and H2O Resistance Ability Over MnOx/TiO2 Catalyst by Expanded Graphite

2020 ◽  
Vol 150 (9) ◽  
pp. 2688-2694
Author(s):  
Hossein Chitsazi ◽  
Rui Wu ◽  
Ningqiang Zhang ◽  
Junda He ◽  
Guizhen Zhang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Low Temperature ◽  
Expanded Graphite ◽  
Tio2 Catalyst ◽  
Nh3 Scr
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