Electrical Behavior of a Catalyst Composed of Laminar Manganese Oxide Supported on γ-Al<sub>2</sub>O<sub>3</sub>
The electrical characterization of catalysts composed of layered manganese oxide in the form of birnessite supported on γ-Al<sub>2</sub>O<sub>3</sub>, which have been successfully used in the combustion of soot, is presented. The results indicate that the electrical...
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MDPI AG
2019-08-01
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author | Nayda P. Arias María E. Becerra Oscar Giraldo |
author_facet | Nayda P. Arias María E. Becerra Oscar Giraldo |
author_sort | Nayda P. Arias |
collection | DOAJ |
description | The electrical characterization of catalysts composed of layered manganese oxide in the form of birnessite supported on γ-Al<sub>2</sub>O<sub>3</sub>, which have been successfully used in the combustion of soot, is presented. The results indicate that the electrical conduction and ion conduction processes are influenced by the amount of the active phase. There was also evidence of Grotthuss-type proton conductivity favored by the presence of surface water on the exposed alumina surface. The above is supported by the porous nature of the catalyst in which the surface area varied between 125.2 ± 1.2 and 159.0 ± 1.1 m<sup>2</sup>/g, evidencing changes in the alumina surface. The conductivity, determined from measurements of impedance spectroscopy, at low frequency showed changes associated with the amount of the active phase. The values ranged from 2.61 × 10<sup>−8</sup> ± 2.1 × 10<sup>−9</sup> Ω<sup>−1</sup>·cm<sup>−1</sup> (pure alumina) to 7.33 × 10<sup>−8</sup> ± 5.9 × 10<sup>−9</sup> Ω<sup>−1</sup>·cm<sup>−1</sup>, 7.21 × 10<sup>−8</sup> ± 5.8 × 10<sup>−9</sup> Ω<sup>−1</sup>·cm<sup>−1</sup> and 4.51 × 10<sup>−7</sup> ± 3.6 × 10<sup>−8</sup> Ω<sup>−1</sup>·cm<sup>−1</sup> at room temperature for catalysts with nominal active phase contents of 5.0, 10.0 and 20.0%, respectively. Such results indicate that it is possible to modulate the electrical properties with variations in the synthesis parameters. |
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spelling | doaj.art-c365258ef6ed40339e1401942aa69eef2022-12-22T01:53:02ZengMDPI AGMolecules1420-30492019-08-012416298410.3390/molecules24162984molecules24162984Electrical Behavior of a Catalyst Composed of Laminar Manganese Oxide Supported on γ-Al<sub>2</sub>O<sub>3</sub>Nayda P. Arias0María E. Becerra1Oscar Giraldo2Grupo de Investigación en Procesos Químicos, Catalíticos y Biotecnológicos, Universidad Nacional de Colombia-Sede Manizales, Kilometro 9 vía al aeropuerto, La Nubia, 170003 Manizales, ColombiaGrupo de Investigación en Procesos Químicos, Catalíticos y Biotecnológicos, Universidad Nacional de Colombia-Sede Manizales, Kilometro 9 vía al aeropuerto, La Nubia, 170003 Manizales, ColombiaGrupo de Investigación en Procesos Químicos, Catalíticos y Biotecnológicos, Universidad Nacional de Colombia-Sede Manizales, Kilometro 9 vía al aeropuerto, La Nubia, 170003 Manizales, ColombiaThe electrical characterization of catalysts composed of layered manganese oxide in the form of birnessite supported on γ-Al<sub>2</sub>O<sub>3</sub>, which have been successfully used in the combustion of soot, is presented. The results indicate that the electrical conduction and ion conduction processes are influenced by the amount of the active phase. There was also evidence of Grotthuss-type proton conductivity favored by the presence of surface water on the exposed alumina surface. The above is supported by the porous nature of the catalyst in which the surface area varied between 125.2 ± 1.2 and 159.0 ± 1.1 m<sup>2</sup>/g, evidencing changes in the alumina surface. The conductivity, determined from measurements of impedance spectroscopy, at low frequency showed changes associated with the amount of the active phase. The values ranged from 2.61 × 10<sup>−8</sup> ± 2.1 × 10<sup>−9</sup> Ω<sup>−1</sup>·cm<sup>−1</sup> (pure alumina) to 7.33 × 10<sup>−8</sup> ± 5.9 × 10<sup>−9</sup> Ω<sup>−1</sup>·cm<sup>−1</sup>, 7.21 × 10<sup>−8</sup> ± 5.8 × 10<sup>−9</sup> Ω<sup>−1</sup>·cm<sup>−1</sup> and 4.51 × 10<sup>−7</sup> ± 3.6 × 10<sup>−8</sup> Ω<sup>−1</sup>·cm<sup>−1</sup> at room temperature for catalysts with nominal active phase contents of 5.0, 10.0 and 20.0%, respectively. Such results indicate that it is possible to modulate the electrical properties with variations in the synthesis parameters.https://www.mdpi.com/1420-3049/24/16/2984supported MnO<sub>X</sub>γ-aluminaionic conductivityporous materials |
spellingShingle | Nayda P. Arias María E. Becerra Oscar Giraldo Electrical Behavior of a Catalyst Composed of Laminar Manganese Oxide Supported on γ-Al<sub>2</sub>O<sub>3</sub> Molecules supported MnO<sub>X</sub> γ-alumina ionic conductivity porous materials |
title | Electrical Behavior of a Catalyst Composed of Laminar Manganese Oxide Supported on γ-Al<sub>2</sub>O<sub>3</sub> |
title_full | Electrical Behavior of a Catalyst Composed of Laminar Manganese Oxide Supported on γ-Al<sub>2</sub>O<sub>3</sub> |
title_fullStr | Electrical Behavior of a Catalyst Composed of Laminar Manganese Oxide Supported on γ-Al<sub>2</sub>O<sub>3</sub> |
title_full_unstemmed | Electrical Behavior of a Catalyst Composed of Laminar Manganese Oxide Supported on γ-Al<sub>2</sub>O<sub>3</sub> |
title_short | Electrical Behavior of a Catalyst Composed of Laminar Manganese Oxide Supported on γ-Al<sub>2</sub>O<sub>3</sub> |
title_sort | electrical behavior of a catalyst composed of laminar manganese oxide supported on γ al sub 2 sub o sub 3 sub |
topic | supported MnO<sub>X</sub> γ-alumina ionic conductivity porous materials |
url | https://www.mdpi.com/1420-3049/24/16/2984 |
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