Model systems

As model system, we selected GDE consisting of silver and PTFE, which are employed during oxygen reduction and carbon dioxide reduction in alkaline electrolyteThe oxygen reduction in alkaline electrolytes on silver-PTFE-GDE was selected as a model system for the investigations aimed at in the research group. This selection was made for the following reasons:

• The system is of direct technical importance for alkaline - and thus potentially Pt-free low-temperature fuel cells and for chlor-alkali electrolysis, in which GDE have recently been used commercially to reduce the cell voltage.
• The electrolysis of CO2 is an important emerging process for the electrochemical utilization of carbon dioxide.
• Well-defined raw materials with high chemical purity are available in different particle sizes and shapes with which GDE can be produced.
• The Research Unit already has extensive experience in the reproducible production of electrodes with different compositions, thicknesses and pore sizes.
• The measurement of the performance of the GDE is possible with relatively simple half-cell setups.
• Because of the relatively large pores (> 1 μm) and the material properties of the silver catalyst, the system is ideal for in-situ and in operando investigations.