Researchers from Shenzhen University and Nanjing Tech University in China have developed a seawater electrolysis system (SES) for the direct electrolysis of seawater, without side reactions or corrosion.
The new method works via self-driven water migration to sidestep the need for a separate desalination process. The energy consumption is purportedly comparable to that of industrial alkaline electrolysis with pure water.
To develop the lab-scale electrolyzer, the scientists separated the two electrode layers with a diaphragm layer and then submerged them in a concentrated hydroxide (OH−) solution – the SDE. They placed a polytetrafluoroethylene (PTFE) membrane between the seawater and the SDE. They claim this design allows the biased diffusion of water vapor, but fully prevents the penetration of liquid seawater and impurity ions such as magnesium, chloride and sulfate.