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

飞秒激光烧蚀可用于选择性地调整金属表面的性能。特征结构扩大了表面，电催化剂可以同时与激光加工环境中的几种几乎任意的活性元素形成合金。为了推进这项技术，本项目将研究电极材料在碱性水电解中的长期稳定性，并记录其气泡特性。重点是通过扩展飞秒激光工艺生成电化学稳定的表面合金，并同时控制流体动力学，以实现电极上气泡引起的低损耗。使用高速显微镜记录气泡特征，并可自由观察操作的电极。自动记录和评估气泡的演变和脱离。这些发现也有助于技术系统的建模。电化学长期测量在定制设计的测试装置中运行，运行时间约为 2000 小时。伴随的材料科学和已建立的电化学方法以及定期电解质测试决定了电极材料的降解。该项目为评估飞秒激光合金催化剂的稳定性奠定了基础。连同对最小气泡引起的损失的控制，这些发现对利用该技术开发的进一步多相催化剂应用产生了影响。

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.