Bubble detachment and long-term stability of femtosecond laser-alloyed electrocatalysts (BLaserCat)

• Applicant: Dr. Thomas Gimpel
• Subject Area: Synthesis and Properties of Functional Materials ; Chemical and Thermal Process Engineering
• Term: since 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 397568108

Femtosecond laser ablation can be used to selectively adjust the properties of metal surfaces. The characteristic structures enlarge the surface and electrocatalysts can be simultaneously alloyed with several almost arbitrary active elements from the laser process environment. In order to advance this technology, the long-term stability of electrode materials in alkaline water electrolysis will be investigated in this project and their gas bubble characteristics recorded. The focus is on the generation of electrochemically stable surface alloys from the extended femtosecond laser process and the simultaneous control of the fluid dynamics in order to achieve low gas bubble-induced losses on the electrodes. The gas bubble characteristics are recorded using high-speed microscopy with a free view on the operated electrodes. The evolution and detachment of the gas bubbles are automatically recorded and evaluated. The findings also contribute to the modelling of technical systems. The electrochemical long-term measurements with operating times of about 2000 hours run in custom designed test units. Accompanying materials science and established electrochemical methods as well as periodical electrolyte tests determine the degradation of the electrode materials. The project creates the basis for evaluating the stability of femtosecond laser-alloyed catalysts. Together with the control of minimal gas bubble-induced losses, the findings have an impact on further multiphase catalyst applications that can be developed with this technology.

• DFG Programme: Research Grants
• Co-Investigator: Professor Dr. Wolfgang Schade