Résumé
The global demand for clean and sustainable energy has been growing over the past decades. This explains the rapid development of new technologies for the production, storage, and better use of energy. Due to their high energy density, Li‐ion batteries are by far the most interesting systems for electrochemical energy storage. However, new electrode materials with high capacity are still needed to improve the battery performance. The development of such advanced materials requires a better understanding of electrochemical reactions within batteries. Mössbauer spectroscopy is a very powerful tool for such a task, as tin and iron are commonly used elements in negative and positive electrode materials, respectively. This technique can be used for the operando characterization of electrochemical reactions, allowing the identification of formed species, oxidation states or changes in local atomic environments during charge–discharge cycles. Some examples are shown in the present chapter to illustrate different mechanisms analyzed by
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Sn and
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Fe Mössbauer spectroscopies. Catalytic reforming is commonly used to produce high‐octane gasoline and improve the energy efficiency of fuel or hybrid vehicles. Mössbauer spectroscopy is of particular interest to improve Sn‐based reforming catalysts as shown here for Al
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O
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supported bimetallic Pt‐Sn and trimetallic Pt‐Sn‐In catalysts. The proposed approach is based on the identification of various Sn‐species based on isomer shift – quadrupole splitting correlation diagrams and in situ measurements. This allows to determine the Sn species for efficient catalytic processes and to optimize the synthesis methods.