CO Oxidation on Ceria Studied by Electrochemical Impedance Spectroscopy

Vendrell, Xavier; Kubyshin, Yu. A.; Mestres, L.; Llorca, Jordi

doi:10.1002/cctc.202001389

Cited by 6 publications

(8 citation statements)

References 52 publications

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“…The description of the synthesis method for CeO 2 is described elsewhere. 56 In the selected temperature range (50-400 • C), all samples were able to completely oxidize CO before reaching the temperature of 350 • C, using a 1:1 molar concentration of CO and O 2 .…”

Section: Resultsmentioning

confidence: 94%

“…In these images, a nanosized CeO 2 (specific surface area of 63.7 m 2 g −1 and pore diameter of 12.4 nm) sample was also included for comparison purposes. The description of the synthesis method for CeO 2 is described elsewhere 56 . In the selected temperature range (50–400°C), all samples were able to completely oxidize CO before reaching the temperature of 350°C, using a 1:1 molar concentration of CO and O 2 .…”

Section: Resultsmentioning

confidence: 99%

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The catalytic activity of the Pr₂Zr₂₋_xFe_xO_7±_δ system for the CO oxidation reaction

et al. 2022

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One of the alternatives to decrease the concentration of CO is its oxidation reaction to CO 2 , which can be made more efficient using catalysts. In this work, it is shown that pyrochlore structures are a promising candidate to act as heterogeneous catalysts due to their chemical and physical properties. For use as a catalyst in this reaction, the Pr 2 Zr 2−x Fe x O 7±δ (x = 0, 0.05, 0.10, and 0.15) system was synthesized by the solvothermal method, firing the powder obtained at temperatures of 1200 and 1400 • C. The diffraction patterns confirmed the pyrochlore structure as the single phase in all the nominal compositions. The Brunauer-Emmett-Teller method and dynamic light-scattering analysis showed an increase in the particle size and a decrease in the specific surface area when increasing the iron concentration and increasing the calcination temperature. The compositions that presented the best catalytic activity were the samples with the highest iron concentration. Moreover, these samples were able to convert all the CO oxidation reactions in a narrower temperature range than a conventional CeO 2 sample. The presence of vacancies and the redox behavior of the elements present are the key factors for the catalysis of this system in the CO oxidation reaction.

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Section: Resultsmentioning

confidence: 94%

Section: Resultsmentioning

confidence: 99%

The catalytic activity of the Pr₂Zr₂₋_xFe_xO_7±_δ system for the CO oxidation reaction

et al. 2022

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“…35 Guesnet et al 36 followed two different approaches to shape gadolinium-doped CeO 2 powders into 25 mm diameter disks: (a) a tape-casting process using additives like phosphate ester, dibutyl phthalate and synthetic polymers, and carbon particles as porogens and (b) die pressing associated with screen-printing. Similar to the latter, Llorca and co-workers 37 reported the compression of CeO 2 powders combined with polyvinyl alcohol into disks of 10 mm diameter using a uniaxial hydraulic press. Methods of shaping of CeO 2 -based structures as catalyst supports for fixedbed reactors have also been reported, such as the pelletization of porous CeO 2 powders previously impregnated with nickel salts into 0.25−0.5 mm pellets for CO methanation.…”

Section: Introductionmentioning

confidence: 99%

Shaping of Porous CeO₂ Powders into Highly Active Catalyst Carriers

Morales

Alarcón

Biset‐Peiró

et al. 2023

ACS Appl. Eng. Mater.

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CeO2 is attracting more and more attention because of its outstanding performance in heterogeneous catalysis, as an active support and a reaction promoter in reactions of industrial interest. We herein describe a novel and scalable manufacturing process of mm-sized CeO2 spheres by a combination of extrusion and spheronization of CeO2 porous powders. In this study, wet paste formulation and fabrication procedures were optimized, and as a result methylcellulose was identified as the best plasticizer for paste extrusion to provide well-defined spherical shapes and smooth surfaces, as well as reproducible batches. After nickel impregnation (10 wt %), the catalytic performance of CeO2 supports was evaluated in the CO2 methanation reaction (T = 250–350 °C, P = 5 bar·g) and compared with that of commercial Al2O3 spheres doped or not with CeO2. These novel CeO2-based catalysts are easily reduced at a moderate temperature and more active than the Al2O3 analogues, particularly at low reaction temperatures and small reactor volumes, properties that make their implementation in emerging reactor configurations very promising.

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“…For instance, it can be used in investigating methanol oxidation, [16][17][18] membrane reactors, [19][20][21][22] and electrocatalytic processes like water splitting 23 and CO oxidation. [24][25][26] Typically, in these studies, the electrical properties of materials, such as conductivity, are merely related to specific frequencies, 24 without conducting a detailed evaluation of the IS data. Consequently, valuable information about the electrical behavior of the sample during catalytic processes can be missing.…”

Section: Introductionmentioning

confidence: 99%

“…Consequently, valuable information about the electrical behavior of the sample during catalytic processes can be missing. 25 To ensure a comprehensive understanding of the electrical behavior during these processes, a deeper analysis of IS data is critical.…”

Section: Introductionmentioning

confidence: 99%

Impedance spectroscopy: A useful technique to unveil the mechanism of a CO oxidation reaction

dos Santos Veiga,

Beltrán‐Mir,

Vendrell

et al. 2023

J Am Ceram Soc.

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In this work, the impedance spectroscopy (IS) technique was used to aid in understanding the reaction mechanism of the CO oxidation reaction using the Pr2Zr2−xFexO7±δ (x = 0 and 0.10) mixed oxide as a heterogeneous catalyst. The catalytic reaction occurred in the same temperature range where there was a decrease in the overall resistivity of the materials. Moreover, it has been observed that within the temperature range where the catalytic process takes place, there is a variation in the A and n parameters of the power law dispersion. Combining IS with catalytic reactions offers a robust approach to enhance the understanding of the mechanisms involved in the CO oxidation reaction. It enables precise analysis of the changes that take place at the solid–gas interface, particularly the generation of reactive oxygen species. Furthermore, it allows examining the relationship between the presence of oxygen vacancies and defects, which directly impact the catalytic process.

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CO Oxidation on Ceria Studied by Electrochemical Impedance Spectroscopy

Cited by 6 publications

References 52 publications

The catalytic activity of the Pr₂Zr₂₋_xFe_xO_7±_δ system for the CO oxidation reaction

The catalytic activity of the Pr₂Zr₂₋_xFe_xO_7±_δ system for the CO oxidation reaction

Shaping of Porous CeO₂ Powders into Highly Active Catalyst Carriers

Impedance spectroscopy: A useful technique to unveil the mechanism of a CO oxidation reaction

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CO Oxidation on Ceria Studied by Electrochemical Impedance Spectroscopy

Cited by 6 publications

References 52 publications

The catalytic activity of the Pr2Zr2−xFexO7±δ system for the CO oxidation reaction

The catalytic activity of the Pr2Zr2−xFexO7±δ system for the CO oxidation reaction

Shaping of Porous CeO2 Powders into Highly Active Catalyst Carriers

Impedance spectroscopy: A useful technique to unveil the mechanism of a CO oxidation reaction

Contact Info

Product

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The catalytic activity of the Pr₂Zr₂₋_xFe_xO_7±_δ system for the CO oxidation reaction

The catalytic activity of the Pr₂Zr₂₋_xFe_xO_7±_δ system for the CO oxidation reaction

Shaping of Porous CeO₂ Powders into Highly Active Catalyst Carriers