Water-impurity-induced nanoscale dynamics of NiFe- and NiCo-based oxygen evolution catalysts under anion exchange membrane water electrolyzer-like conditions

• Applicant: Dr. Johanna Schröder
• Subject Area: Technical Chemistry ; Physical Chemistry of Solids and Surfaces, Material Characterisation
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 581129996

The project’s main goal is to understand the potential of ternary oxygen evolution reaction (OER) precatalysts in impure water environments for anion exchange membrane water electrolyzers (AEMWEs). Ternary structures with distinct differences in precatalyst properties (e.g. hydroxides versus oxides) are prepared via electrodeposition, co-precipitation, and flame-spray pyrolysis. The tailored precatalyst properties with varied metal ratios are expected to result in distinct differences of formation kinetics of active oxyhydroxide (OOH) species and of OER performance (in ultrapure water). The use of the so-called gas-diffusion electrode (GDE) setup combing realistic AEMWE-like conditions with straightforward, high-throughput testing in fundamental rotating disk electrode (RDE) setups allows the application of test protocols of both RDE setups and AEMWE devices achieving transferability from fundamental to AEMWE-like test conditions and results. The characterization post electrocatalysis will allow the correlation of OER performance to precatalyst and post-treatment properties. More realistic AEMWE-like conditions achieved considering the presence of Fe-contamination from stainless steel components, Fe incorporation is expected to affect catalyst activation and the OER performance depending on the precatalyst properties. Adding additionally different amounts of drinking water impurities (such as Na+, Ca2+, Mn2+, Cl-, HCO3-, SO42-) an interplay of the different ions and ion concentrations, as well as the precatalyst properties is expected to affect the OER catalyst performances (both activity and durability). With the aid of an extensive catalyst (surface versus bulk) and membrane characterization combining ex-situ and in-situ/operando techniques active sites of the prepared structures and their degradation depending on the ternary precatalyst properties will be revealed. Therefore, design-criteria for OER catalysts towards complex water compositions will be identified for a decentralized AEMWE application using abundant water resources.

• DFG Programme: Research Grants