Transient High-Temperature Oxygen Evolution Reaction

瞬时高温析氧反应

• 批准号: 406945544
• 负责人: Professor Dr. Rüdiger-A. Eichel
• 金额: --
• 依托单位: IEK-9: Grundlagen der Elektrochemie
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/406945544?language=en
• 关键词: Transient; Temperature; Oxygen; Evolution; Reaction

Water (or steam) electrolysis, producing hydrogen gas as a chemical energy carrier, is a corner stone for the long-term storage of intermittent, renewably generated electricity. Hydrogen production is always accompanied by oxygen evolution at the counter- or air-electrode of the electrolysis cell. This electro-catalytic oxygen evolution reaction (OER) plays a decisive role for the efficiency of the hydrogen production due unfavorable overpotentials, causing severe overall losses. Among the known electrolysis processes, high-temperature solid oxide electrolysis cells (SOECs) constitute the most promising technology for the operation in a scenario with intermittent power supply, as elevated temperatures yield higher ionic conductivity in the electrolyte, faster electrode reaction kinetics, and the lowest OER overpotentials.In this project, the scope of applicability of high-temperature SOECs, which have been optimized for optimum performance under constant load in the past, will be extended to dynamic operating conditions. Problems of accelerated degradation of the air-electrode like delamination and chemical instability of the electro-catalyst materials will be addressed. The development of improved oxygen-conducting solid electrolytes and OER electro-catalyst coatings, as well as the optimization of transient operating conditions will result in the production of refined SOEC cells and stack setups. To meet these objectives, a fundamental understanding of the electrochemical and relevant atomic-scale processes in the bulk phases and at interfaces of the state-of-the-art materials LSM and LSCF, supported on YSZ will be developed. For this we take a holistic approach, linking ab initio theoretical and operando characterization techniques for real-time investigations at the microscopic scale.

水(或蒸汽)电解产生氢气作为一种化学能量载体，是长期储存间歇的、可再生的电力的基石。制氢总是伴随着电解槽的对电极或空气电极放氧。这种电催化析氧反应(OER)对制氢效率起着决定性的作用，因为不利的过电位造成了严重的整体损失。在已知的电解工艺中，高温固体氧化物电解槽(SOECs)是最有希望在间歇供电的情况下运行的技术，因为高温可以在电解液中产生更高的离子电导率，更快的电极反应动力学和最低的OER过电位。在这个项目中，高温SOECs的适用范围将被扩展到动态操作条件下，过去高温SOECs已经被优化为在恒定负载下的最佳性能。将解决空气电极加速降解的问题，如电催化剂材料的分层和化学不稳定性。改进的导氧固体电解质和OER电催化剂涂层的开发，以及瞬时操作条件的优化，将导致生产精细化的SOEC电池和电堆装置。为了实现这些目标，将对YSZ支持的最先进材料LSM和LSCF的体相和界面上的电化学和相关原子尺度过程有一个基本的了解。为此，我们采取了一种整体的方法，将从头算理论和操作数表征技术联系起来，用于在微观尺度上进行实时研究。