Ammonia oxidation on electrodeposited Pt–Ir alloys
| Autor: | Elena Pastor, José L. Rodríguez, B.A. López de Mishima, E. Moran, C. Cattaneo, S. P. Silvetti, H.T. Mishima |
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| Rok vydání: | 2007 |
| Předmět: |
Auger electron spectroscopy
Inorganic chemistry Alloy Analytical chemistry engineering.material Condensed Matter Physics Electrochemistry Crystal Ammonia chemistry.chemical_compound chemistry engineering General Materials Science Texture (crystalline) Electrical and Electronic Engineering Cyclic voltammetry Bimetallic strip |
| Zdroj: | Journal of Solid State Electrochemistry. 12:583-589 |
| ISSN: | 1433-0768 1432-8488 |
| DOI: | 10.1007/s10008-007-0407-0 |
| Popis: | Ammonia electro-oxidation on Pt–Ir alloys has been studied applying cyclic voltammetry and differential electrochemical mass spectrometry (DEMS), and the results were compared with pure Pt. Bimetallic alloys were prepared by electrodeposition and characterized using X-ray diffractometry (XRD) and Auger spectroscopy, before and after oxidation of ammonia. Pt/Ir atomic composition was 70:30 obtained from 1:1 solutions. Substitution alloys were established where Ir atoms replace Pt positions in the face-centered cubic structure. Preferential crystal orientations were detected in the electrodeposits with the development of a crystallographic texture. DEMS showed that N2 is the main product during ammonia oxidation for both Pt and Pt–Ir, but the formation of nitrogen oxides is observed for E > 0.8 VRHE. The yield of N2 is higher for the alloy, which also displays lower poisoning of the surface when increasing ammonia concentration. These results confirm Pt–Ir alloys as alternatives to Pt electrodes concerning ammonia oxidation. Finally, it was observed that XRD patterns, as well as texture coefficient values, change after using the electrodeposits for ammonia oxidation, with the less compact planes the more affected ones. |
| Databáze: | OpenAIRE |
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