A new method of producing green hydrogen from the ocean was discovered by researchers from the University of Adelaide and an international team of scientists from China’s Tianjin University, Nankai University, and Kent State University in the United States.
They succeeded in producing green hydrogen directly from water taken from the ocean and used it in a commercial electrolyzer. All they did was filter the seawater to remove solids and microorganisms. They published their paper in Nature Energy on January 30th.
“Seawater is abundant but must be desalinated before use in typical proton exchange membrane (PEM) electrolyzers. Here we report direct electrolysis of real seawater that has not been alkalized nor acidified, achieving long-term stability exceeding 100 h at 500 mA cm−2 and similar performance to a typical PEM electrolyzer operating in high-purity water,” according to the paper.
As per the research, this was achieved by introducing a Lewis acid layer on transition metal oxide catalysts to dynamically split water molecules and capture hydroxyl anions. Such in situ generated local alkalinity facilitates the kinetics of both electrode reactions and avoids chloride attack and precipitate formation on the electrodes.
The scientists will work on scaling up the system by using a larger electrolyzer that could be used in commercial processes like hydrogen generation for fuel cells and ammonia synthesis.