Enhanced performance of microbial electrolysis cells using microstructured electrodes

Abstract

A microbial electrolysis cell is set up with the purpose to realize an efficient power-to-gas process. Both hydrogen production by electrolysis and biomethanization proceed in the same reactor cell. In particular, the formation of hydrogen bubbles is strongly governed by the surface properties of the used stainless steel electrodes. Here, we introduce surface topography modifications on the micron-scale to enhance the electrical transport in the cell and support charge conversion into hydrogen. Furthermore, it is analyzed if hydrogen bubble detachment can be supported to form smaller bubbles that can be efficiently converted into methane. A positive influence on the electrical transport is found and explained by a surface-controlled suppression of bio-film passivation.