The Design and Fabrication of a 3D-Printed Electrolyzer with Membrane-Less Technology for Green H₂ Production ^†

Hydrogen production through water splitting is a popular technology. The reaction takes place in an electrolyzer unit. There are different types of electrolyzers available, including proton exchange membranes (PEMs), anion exchange membranes (AEMs), and alkaline and solid oxide electrolyzers. Although PEMs are a widely used commercial electrolyzer, they are very sensitive, not very durable, and have a high cost due to the membrane. To eliminate the cost of the membrane, the concept of membrane-less electrolysis technology was developed.

In this study, a new membrane-less electrolyzer design was proposed with a flow-through electrolyzer, as shown in Figure 1.

The design was manufactured with the help of 3D printing technology with acrylonitrile butadiene styrene (ABS) polymer material that is more stable in basic media. To increase the conductivity of water, a 4 M KOH solution was provided for electrolysis. In this design, electrodes were placed at an angle of 30° to each other. The generated hydrogen and oxygen gases were separated from each other using the effect of the flow of water between the electrodes. The tapered inlet was provided to maintain a proper laminar flow through the inlet. In the middle of the electrolyzer, a divider was also provided for separating the generated hydrogen and oxygen gas. A Ni mesh with an 80-grit size was used in the place of electrodes. The purity of the generated gas was measured via a gas chromatography instrument. A H₂ purity of about 99.85% was achieved by using a Ni mesh as an electrode at room temperature and normal pressure.