Heppe Nils, Gallenkamp Charlotte, Snitkoff-Sol Rifael Z, Paul Stephen D, Segura-Salas Nicole, Haak Hendrik, Moritz Dominik C, Kaiser Bernhard, Jaegermann Wolfram, Potapkin Vasily, Jafari Atefeh, Schünemann Volker, Leupold Olaf, Elbaz Lior, Krewald Vera, Kramm Ulrike I
Catalysts and Electrocatalysts, Eduard-Zintl-Institute of Inorganic and Physical Chemistry, Department of Chemistry, Technical University Darmstadt, Otto-Berndt-Str. 3, 64287 Darmstadt, Germany.
Quantum Chemistry, Eduard-Zintl-Institute of Inorganic and Physical Chemistry, Department of Chemistry, Technical University Darmstadt, Peter-Grünberg-Str. 4, 64287 Darmstadt, Germany.
J Am Chem Soc. 2024 May 8;146(18):12496-12510. doi: 10.1021/jacs.4c00436. Epub 2024 Apr 17.
Nuclear forward scattering (NFS) is a synchrotron-based technique relying on the recoil-free nuclear resonance effect similar to Mössbauer spectroscopy. In this work, we introduce NFS for and measurements during electrocatalytic reactions. The technique enables faster data acquisition and better discrimination of certain iron sites in comparison to Mössbauer spectroscopy. It is directly accessible at various synchrotrons to a broad community of researchers and is applicable to multiple metal isotopes. We demonstrate the power of this technique with the hydrogen evolution mechanism of an immobilized iron porphyrin supported on carbon. Such catalysts are often considered as model systems for iron-nitrogen-carbon (FeNC) catalysts. Using and NFS in combination with theoretical predictions of spectroscopic data enables the identification of the intermediate that is formed prior to the rate-determining step. The conclusions on the reaction mechanism can be used for future optimization of immobilized molecular catalysts and metal-nitrogen-carbon (MNC) catalysts.
核前向散射（NFS）是一种基于同步加速器的技术，它依赖于类似于穆斯堡尔光谱的无反冲核共振效应。在这项工作中，我们引入了NFS用于电催化反应过程中的[具体内容缺失]和[具体内容缺失]测量。与穆斯堡尔光谱相比，该技术能够实现更快的数据采集，并能更好地区分某些铁位点。它在各种同步加速器上可供广大研究人员直接使用，并且适用于多种金属同位素。我们用负载在碳上的固定化铁卟啉的析氢机理证明了该技术的强大功能。这类催化剂通常被视为铁氮碳（FeNC）催化剂的模型体系。结合光谱数据的理论预测，使用[具体内容缺失]和[具体内容缺失]NFS能够识别在速率决定步骤之前形成的中间体。关于反应机理的结论可用于未来固定化分子催化剂和金属氮碳（MNC）催化剂的优化。
