Best Poster Award
Konrad Ehelebe won the Best Poster Award at the GDCh Electrochemistry Conference 2018.
Copyright: Deutsche Metrohm GmbH & Co. KG
PhD Student Konrad Ehelebe of Prof. Dr. Mayrhofer´s research unit „Electrocatalysis“ won the Best Poster Award for his research poster about “Bridging the gap between fundamental and applied fuel cell electrocatalysis: High-throughput catalyst screening of gas diffusion electrodes". The prize was awarded by Deutsche Metrohm GmbH & Co. KG at the GDCh Electrochemistry Conference in Ulm. Outstanding electrochemists from Germany and from abroad highlighted research results and current trends at this conference which focused on electrochemical surface science, from fundamentals to applications. Mr. Ehelebe was successful in a very competitive poster session of over 250 posters.
In the award-winning work, a method for high-throughput catalyst screening of gas diffusion electrodes (GDEs) was proposed to close the gap between fundamental and applied fuel cell electrocatalysis.
Although modern fuel cells are based on the utilization of solid membranes, fundamental catalyst research is mainly done in aqueous solutions via rotating disk electrode (RDE) or similar techniques. However, due to low solubility of reactant gases (H2 and O2) in those electrolytes mass-transfer limitation occurs at potentials relevant for the fuel cell operation (0.6 – 0.8 V vs. RHE ). Therefore, in addition to RDE measurements, membrane electrode assemblies (MEA) tests are employed to evaluate catalysts in realistic fuel cell conditions. These experiments are complex, time-consuming and require large quantities of catalysts and expensive test equipment. To close the gap between fundamental and applied research, intermediary testing methods need to be introduced which should combine the advantages of both approaches. Half-cell measurements using GDEs have recently been considered to be the most suitable method allowing high mass transport catalyst screening in relevant potential ranges and realistic electrode structures. [1-3]
In this work, first studies of catalyst screening of GDEs have been demonstrated. Furthermore, the concept to extend this approach by enabling high-throughput screening of catalysts was presented. For this, a modification to a scanning flow cell (SFC)  setup is suggested. With this device it is possible to rapidly screen the activity of electrocatalysts depending on different material properties (e.g. catalyst loading gradients on one axis and structural property gradients such as pore size, ionomer content of membrane etc. on the other axis) using GDEs. Thus, the most suitable electrodes under realistic fuel cell conditions could be worked out in a fraction of the time required for the conventional methods.
 Zalitis, C.M., Phys. Chem. Chem. Phys. 2013, 15(12), 4329-4340.
 Pinaud, B.A., J. Electrochem. Soc. 2017, 164(4), F321-F327.
 Inaba, M., Energy Environ. Sci. 2018, 11(4), 988-994.
 Klemm , S., Electrochem. Comm. 2011, 13(12), 1533-1535.