دورية أكاديمية
Neodymium nickelate Nd 2-x Sr x Ni 1-y Co y O 4 ± d (x and y = 0 or 0.05) as cathode materials for the oxygen reduction reaction
| العنوان: | Neodymium nickelate Nd 2-x Sr x Ni 1-y Co y O 4 ± d (x and y = 0 or 0.05) as cathode materials for the oxygen reduction reaction |
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| المؤلفون: | Ferkhi, M., Rekaik, M., Khaled, A., Cassir, M., Pireaux, Jean-Jacques |
| المصدر: | Ferkhi , M , Rekaik , M , Khaled , A , Cassir , M & Pireaux , J-J 2017 , ' Neodymium nickelate Nd 2-x Sr x Ni 1-y Co y O 4 ± d (x and y = 0 or 0.05) as cathode materials for the oxygen reduction reaction ' , Electrochimica Acta , vol. 229 , pp. 281-290 . https://doi.org/10.1016/j.electacta.2017.01.023Test |
| سنة النشر: | 2017 |
| المجموعة: | Research Portal - University of Namur / Portail de la recherche de l'Université de Namur |
| مصطلحات موضوعية: | Electrochemical behavior, Impedance spectroscopy, Nickelate materials, ORR, XPS analysis |
| الوصف: | The oxygen reduction reaction (ORR) was investigated using two new cathode materials based on neodymium nickelate with formula Nd 2-x Sr x Ni 1-y Co y O 4 ± δ (with x and y = 0 or 0.05) prepared by the citrate method. The ORR was measured in 0.5 M NaOH with a rotating disk electrode (RDE) at different rotation speeds after purging with pure oxygen. The synthesized materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), whereas the electrochemical analysis was obtained by linear voltammetry and impedance spectroscopy. The results show that before the ORR, the grains of the undoped material are spherical in shape with a size around 400 nm, while after the oxygen reduction reaction, the grain size increases. In the doped material, on the contrary, the results are reversed and the grain size becomes smaller. In addition, we show that the ORR mechanism proceeds in a single step in the undoped material while it is carried out in two successive steps in the case of the doped one. XPS analysis confirms that the sites responsible for the ORR are the OH − groups. Doping with Sr or Co does not improve the electrochemical properties: this dopant adversely affects the formation of the sites responsible for the dissociation of molecular oxygen. For larger hydroxide groups content (2.30, Nd 2 NiO 4 ± δ ) the electrochemical currents are much greater relative to that of the other Nd 1.95 Sr 0.05 Ni 0.95 Co 0.05 O 4 ± δ (0.98) material. This work helps to understand the role of OH − groups, and the reduction mechanisms with 2 and 4 electrons. |
| نوع الوثيقة: | article in journal/newspaper |
| اللغة: | English |
| العلاقة: | https://researchportal.unamur.be/en/publications/7d869b66-8267-4451-b839-215ae4af811fTest |
| DOI: | 10.1016/j.electacta.2017.01.023 |
| الإتاحة: | https://doi.org/10.1016/j.electacta.2017.01.023Test https://researchportal.unamur.be/en/publications/7d869b66-8267-4451-b839-215ae4af811fTest http://www.scopus.com/inward/record.url?scp=85011004819&partnerID=8YFLogxKTest |
| حقوق: | info:eu-repo/semantics/closedAccess |
| رقم الانضمام: | edsbas.EF6C0DFA |
| قاعدة البيانات: | BASE |
| DOI: | 10.1016/j.electacta.2017.01.023 |
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