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.