Porous materials are frequently used as e.g. electrodes or porous transport layers in various types of electrolyzers. A better understanding of the bubble dynamics on porous electrodes is especially important to optimize new electrolyzer designs like membraneless electrolyzers. The developed 3-electrode cell was optimized with regard to the analysis of the bubble nucleation, growth and detachment on the applied working electrode. Noteworthy in this regard is the 2-dimensional optical measurement system to characterize the bubble dynamics from the side and top. The cell provides a platform to run parametric studies in alkaline electrolytes. The present data set compares three different expanded nickel metals at applied current densities of |j|= 10, 20, 50, 100 or 200 mA/cm² and flow rates of ̇V̇ = 0 or 5 ml/min. As electrolyte 1 M KOH is used. An overview of all performed experiments and the main parameters (current density j and flow rate V̇) is given in the file Overview of all performed experiments.pdf. The data is analyzed as described in the corresponding journal publication Bubble size distribution and electrode coverage at porous nickel electrodes in a novel 3-electrode flow-through cell. For each parameter set 3 data sets are given to ensure statistical confidence. Each data set, stored as .hdf5-file, is structured in groups as follows: Electrochemical Measurement Data Sideview Raw Images Topview Raw Images Results Detected Bubbles Electrode Coverage In the attributes assigned to the groups in the .hdf5-file all relevant metadata is given, including the experimental parameters, used devices and characteristics of the mounted WE. In addition to exemplary data sets for all three electrodes, the CAD files of the experimental setup used and sample videos of the raw images are also provided within this data publication. The remaining data sets of all measurements performed can be made available upon request.

Grants: German Federal Ministry of Education and Research (contract No. 03SF0672)