Microelectrochemical and microspectroelectrochemical studies of the incorporation of iron ions in nickel oxide and its effect on the oxygen evolution activity in alkaline water electrolysis - MicroSpec

高效储存风能和太阳能产生的可再生电力是这一时期的核心挑战之一。除了为发电机和用户提供电能的蓄电池外，电解法还可以为化学工业提供重要的原料。氢是目前发展的目标中心分子。除了酸膜电解法(PEM)依赖于稳定、高效但同时稀有和昂贵的材料外，碱性水电解法在原料供应从化石能源向可再生能源的必要转变中发挥着重要作用。近年来，碱性膜的研究取得了决定性的进展，其中碱性膜电解(AEM)起到了重要的推动作用。现在可以使用由廉价和容易获得的过渡金属化合物组成的电极材料。然而，对于这些还缺乏了解和优化的需要，这需要进一步的研究，特别是在动力学强抑制的放氧反应(OER)方面。在这种情况下，镍铁双氢氧化物(NiFe-LDH)尤其重要，因为它表现出最低的电压损失。在本项目中，将研究用于析氧反应的新型镍基催化剂。该项目的中心思想是将高温镍氧化物的材料知识与空间分辨电化学和原位光谱的方法发展结合起来。一方面，需要对不同温度、不同铁含量的镍粉进行综合研究，以开发出具有高活性和稳定性的新型电化学析氧材料。使用镍基材料代替氢氧化物材料的方法源于我们自己的结果，在高温下，镍氧化物表现出与氢氧化物相当的活性，而稳定性明显提高。另一方面，本项目将以新的方法进一步发展原位拉曼显微镜和扫描电化学显微镜(SECM)。最后，这一组合装置将用于镍(铁)氧化物电极的微电化学和光谱研究，为活性-结构关系以及失活和稳定的原因提供新的见解。结合材料发现，将对镍基催化剂的结构变化动力学有更深入的了解，为碱性电解中更稳定的OER催化剂提供新的途径。

The efficient storage of renewably generated electricity from wind and sun is one of the central challenges of this time. In addition to accumulators for feeding in and out electricity from generators and for consumers, electrolysis processes can provide important raw materials for the chemical industry. Hydrogen is the central molecule targeted by current developments. In addition to acidic membrane electrolysis (PEM), which relies on stable and efficient but at the same time rare and expensive materials, alkaline water electrolysis plays an important role in the necessary transformation of the feedstock supply from fossil to renewable energies. In recent years, decisive progress has been made in alkaline membranes, with alkaline membrane electrolysis (AEM) providing a major boost. Electrode materials consisting of inexpensive and readily available transition metal compounds can now be used. For these, however, there is a lack of understanding and a need for optimization, which necessitates further research, especially for the side of the kinetically strongly inhibited oxygen evolution reaction (OER). In this context, the nickel-iron double hydroxide (NiFe-LDH) is of particular importance, since it exhibits the lowest voltage losses. In this project, new nickel oxide-based catalysts for the oxygen evolution reaction will be investigated. The central idea of the project is to combine material knowledge of high temperature nickel oxides and method development of spatially resolved electrochemistry and in situ spectroscopy. On the one hand, powdered nickel oxides treated at different temperatures with different iron contents are to be comprehensively investigated in order to develop novel materials with high activity and simultaneous stability for electrochemical oxygen evolution. The approach to use nickel oxide-based instead of the hydroxide-based materials is derived from our own results in which high temperature nickel oxide showed comparable activity with significantly improved stability compared to the hydroxide. On the other hand, the combined in situ Raman microscopy and scanning electrochemical microscopy (SECM) will be further developed with novel approaches in this project. Finally, this combined setup will be used for the microelectrochemical and spectroscopic investigation of nickel (iron) oxide electrodes, providing new insights into activity-structure relationships and causes of deactivation and stability. Combined with the material findings, a deeper understanding of the dynamics of nickel-based electrocatalysts in terms of structural changes will be obtained, providing new approaches for more stable OER catalysts in alkaline electrolysis.