Investigation of surface reactions on novel SOFC cathode materials by in-situ photoelectron spectroscopy

在寻求清洁和可持续能源技术的过程中，固体氧化物燃料电池(SOFC)是高效燃料能量转换器的一个有吸引力的候选者。较高的运行温度(500-1000°C)使SOFC成为热电联产(CHP)系统的理想选择，这对于分散的能源网络来说是一个有吸引力的选择。向本地生产能源的转变与较小的运输损失和更大的灵活性相关。SOFC的一个关键优势是燃料的灵活性，即它不仅限于使用氢气作为燃料，而且可以利用碳氢化合物发电，与燃烧相比，效率高得多，排放也少得多。此外，通过化学反应将化石燃料直接转化为电力，从环境角度来看也使这项技术具有吸引力，因为它与温室气体的排放要少得多。提高SOFC性能的关键在于了解控制阴极中氧的掺入和传输的原子过程，这通常是最先进的SOFC的限制因素。因此，拟议的研究项目将集中在分子水平上了解固体氧化物燃料电池(SOFC)阴极材料表面的氧还原反应(ORR)。除了对速率决定步骤(RDS)的研究外，在不同氧化物之间观察到的新的相界现象将通过先进的同步加速器环境压力光电子能谱(APPES)进行原位探索。该项目将有助于理解为什么某些阴极异质界面对ORR反应非常强烈，以及ORR过程中阴极表面的原子过程，这对于以更好的经济性和更长的寿命提高SOFC在中温下的性能是非常重要的。

In the search for clean and sustainable energy technologies, solid oxide fuel cells (SOFCs) are an attractive candidate for highly efficient fuel-to-energy converters. The high operation temperatures (500 - 1000°C) make SOFCs an ideal candidate for combined heat and power (CHP) systems, which is an attractive option for a decentralized energy network. The shift toward a local production of energy is associated with smaller transport losses and a greater flexibility. A key advantage of SOFC is the fuel flexibility, i.e. it is not limited to using hydrogen as the fuel, but can utilize hydrocarbons to generate electricity with much higher efficiency and reduced emissions compared to combustion. In addition, the direct conversion of fossil fuel into electrical power via a chemical reaction makes this technology attractive also from an environmental point of view, since it is associated with much less emission of green-house gases. The key to improving SOFC performance lies in understanding the atomistic processes that govern oxygen incorporation and transport in the cathode, which is often the limiting factor in state-of-the-art SOFCs. The proposed research project will therefore be centered on gaining a molecular level understanding of the oxygen reduction reaction (ORR) on the surface of cathode materials for solid oxide fuel cells (SOFCs). In addition to investigations of the rate-determining-step (rds), novel phenomena observed at the phase boundaries between dissimilar oxides will be explored in-situ via advanced synchrotron-based ambient pressure photoelectron spectroscopy (APPES). The proposed project is expected to contribute significantly to the understanding of why certain cathode hetero-interfaces are very highly reactive to ORR and the atomistic processes on the cathode surface during ORR, which is highly important for advancing the performance of SOFCs at intermediate temperatures with better economics and longer lifetime.