Gebhard Marcus, Paulisch Melanie, Hilger André, Franzen David, Ellendorff Barbara, Turek Thomas, Manke Ingo, Roth Christina
Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustraße 3, 14195 Berlin, Germany.
Institute of Applied Materials, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin, Germany.
Materials (Basel). 2019 Apr 18;12(8):1275. doi: 10.3390/ma12081275.
Oxygen-depolarized cathodes are a novel concept to be used in chlor-alkali electrolysis in order to generate significant energy savings. In these porous gas diffusion electrodes, hydrophilic and catalytically active microsized silver grains and a hydrophobic polytetrafluoroethylene cobweb structure are combined to obtain the optimum amount of three-phase boundaries between the highly alkaline electrolyte and the oxygen gas phase to achieve high current densities. However, the direct correlation between specific electrode structure and electrochemical performance is difficult. In this work, we report on the successful design and adaptation of an in-operando cell for X-ray (micro-computed tomography, synchrotron) and neutron imaging of an operating oxygen-depolarized cathode under realistic operation conditions, enabling the investigation of the electrolyte invasion into, and distribution inside, the porous electrode for the first time.
氧去极化阴极是一种用于氯碱电解的新概念，旨在大幅节省能源。在这些多孔气体扩散电极中，亲水性且具有催化活性的微米级银颗粒与疏水性聚四氟乙烯蛛网状结构相结合，以在高碱性电解质与氧气相之间获得最佳数量的三相边界，从而实现高电流密度。然而，特定电极结构与电化学性能之间的直接关联很难确定。在这项工作中，我们报告了一种用于在实际运行条件下对运行中的氧去极化阴极进行X射线（微观计算机断层扫描、同步加速器）和中子成像的在线电池的成功设计与适配，这使得首次能够研究电解质侵入多孔电极及其在电极内部的分布情况。
