Membrane-less alkaline water electrolyzers: current state of research

Alkaline water electrolysis systems have the potential to facilitate the transition toward environmentally friendly energy storage in the form of hydrogen considering their technological maturity and possibility to utilize earth abundant catalysts. This review explores novel cell designs of alkaline membrane-less electrolyzers as potential systems for low-cost and efficient hydrogen production. These electrolyzers exploit geometry, reaction decoupling, and electrolyte or capillary flow for separating the gaseous products in the absence of a membrane. Recent progress in these membrane-less electrolyzer architectures has led to efficient and cost-effective hydrogen production cells with high production rates and purity. However, challenges remain in scaling up and stacking these designs for commercial applications.