Hydrogen oxidation kinetics on platinum-palladium bimetallic thin films for solid acid fuel cells
Solid acid fuel cells (SAFCs) based on the proton-conductive electrolyte CsH2PO4 have shown promising power densities at an intermediate operating temperature of ∼250 °C. However, Pt loadings in SAFCs remain higher than desirable, and the electrocatalysis mechanisms in these devices are still unknow...
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| Format: | Article |
| Language: | English |
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AIP Publishing LLC
2019-01-01
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| Series: | APL Materials |
| Online Access: | http://dx.doi.org/10.1063/1.5050093 |
| _version_ | 1811254915055484928 |
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| author | Haemin Paik Andrey V. Berenov Stephen J. Skinner Sossina M. Haile |
| author_facet | Haemin Paik Andrey V. Berenov Stephen J. Skinner Sossina M. Haile |
| author_sort | Haemin Paik |
| collection | DOAJ |
| description | Solid acid fuel cells (SAFCs) based on the proton-conductive electrolyte CsH2PO4 have shown promising power densities at an intermediate operating temperature of ∼250 °C. However, Pt loadings in SAFCs remain higher than desirable, and the electrocatalysis mechanisms in these devices are still unknown. Here, hydrogen oxidation kinetics on Pt and Pt-Pd bimetallic thin film electrodes on CsH2PO4 have been evaluated to establish the potential for a beneficial role of Pd in SAFC anodes. Symmetric cells fabricated by depositing a metal film on both sides of electrolyte discs are characterized for studying hydrogen electro-oxidation across the gas|metal|CsH2PO4 structure. It was found that Pd reacts with CsH2PO4, forming palladium phosphide at the metal-electrolyte interface. Accordingly, the activity of Pd was examined in a bilayer geometry of Pd|Pt|CsH2PO4|Pt|Pd. The bilayer Pt|Pd films showed much higher activity for hydrogen electro-oxidation than films of Pt alone, as measured by AC impedance spectroscopy. Ex situ low energy ion scattering and scanning transmission electron microscopy revealed that Pd diffused into the Pt layer under operating conditions. The dramatic impact of Pd along with its presence throughout the film suggests that it catalyzes reactions at both the metal-gas and metal-electrolyte interfaces, as well as increasing hydrogen diffusion rates through the films. |
| first_indexed | 2024-04-12T17:15:41Z |
| format | Article |
| id | doaj.art-36bd3309ec5d4927b242098cc46615d2 |
| institution | Directory Open Access Journal |
| issn | 2166-532X |
| language | English |
| last_indexed | 2024-04-12T17:15:41Z |
| publishDate | 2019-01-01 |
| publisher | AIP Publishing LLC |
| record_format | Article |
| series | APL Materials |
| spelling | doaj.art-36bd3309ec5d4927b242098cc46615d22022-12-22T03:23:39ZengAIP Publishing LLCAPL Materials2166-532X2019-01-0171013201013201-610.1063/1.5050093001993APMHydrogen oxidation kinetics on platinum-palladium bimetallic thin films for solid acid fuel cellsHaemin Paik0Andrey V. Berenov1Stephen J. Skinner2Sossina M. Haile3Materials Science, California Institute of Technology, 1200 California Blvd., Pasadena, California 91125, USADepartment of Materials, Imperial College London, Exhibition Road, London SW7 2AZ, United KingdomDepartment of Materials, Imperial College London, Exhibition Road, London SW7 2AZ, United KingdomMaterials Science, California Institute of Technology, 1200 California Blvd., Pasadena, California 91125, USASolid acid fuel cells (SAFCs) based on the proton-conductive electrolyte CsH2PO4 have shown promising power densities at an intermediate operating temperature of ∼250 °C. However, Pt loadings in SAFCs remain higher than desirable, and the electrocatalysis mechanisms in these devices are still unknown. Here, hydrogen oxidation kinetics on Pt and Pt-Pd bimetallic thin film electrodes on CsH2PO4 have been evaluated to establish the potential for a beneficial role of Pd in SAFC anodes. Symmetric cells fabricated by depositing a metal film on both sides of electrolyte discs are characterized for studying hydrogen electro-oxidation across the gas|metal|CsH2PO4 structure. It was found that Pd reacts with CsH2PO4, forming palladium phosphide at the metal-electrolyte interface. Accordingly, the activity of Pd was examined in a bilayer geometry of Pd|Pt|CsH2PO4|Pt|Pd. The bilayer Pt|Pd films showed much higher activity for hydrogen electro-oxidation than films of Pt alone, as measured by AC impedance spectroscopy. Ex situ low energy ion scattering and scanning transmission electron microscopy revealed that Pd diffused into the Pt layer under operating conditions. The dramatic impact of Pd along with its presence throughout the film suggests that it catalyzes reactions at both the metal-gas and metal-electrolyte interfaces, as well as increasing hydrogen diffusion rates through the films.http://dx.doi.org/10.1063/1.5050093 |
| spellingShingle | Haemin Paik Andrey V. Berenov Stephen J. Skinner Sossina M. Haile Hydrogen oxidation kinetics on platinum-palladium bimetallic thin films for solid acid fuel cells APL Materials |
| title | Hydrogen oxidation kinetics on platinum-palladium bimetallic thin films for solid acid fuel cells |
| title_full | Hydrogen oxidation kinetics on platinum-palladium bimetallic thin films for solid acid fuel cells |
| title_fullStr | Hydrogen oxidation kinetics on platinum-palladium bimetallic thin films for solid acid fuel cells |
| title_full_unstemmed | Hydrogen oxidation kinetics on platinum-palladium bimetallic thin films for solid acid fuel cells |
| title_short | Hydrogen oxidation kinetics on platinum-palladium bimetallic thin films for solid acid fuel cells |
| title_sort | hydrogen oxidation kinetics on platinum palladium bimetallic thin films for solid acid fuel cells |
| url | http://dx.doi.org/10.1063/1.5050093 |
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