Advancements in membrane-less electrolysis configurations: Innovations and challenges

Ionic conductive membranes have provided significant advantages in low-temperature water electrolysis configurations, but their poor stability and high cost have prompted researchers to develop various types of membrane-less electrolysis configurations of reduced design complexity and lower costs. This paper reviews recent studies in the field, comparing the results obtained with different approaches and critically advising about the main advantages and challenges to be overcome. Notable among these is the electrolyte flow- by strategy, which uses closely spaced planar electrodes and laminar flow to keep hydrogen and oxygen bubbles separated without a membrane. Various other approaches have also been investigated such as: flow-through electrodes, bubbles free gas diffusion electrodes, organic-assisted electrolysis process and microbial electrolysis cells. The different approaches discussed on the manuscript generates significant interest within the scientific community, offering an opportunity to simplify innovative electrolysis configurations addressing new scientific challenges associated with traditional electrolysis methods.