Researchers at RMIT University in Australia have devised an innovative and promising method for increasing the production of green hydrogen by 14 times – by Using sound waves through electrolysis to split water.
According to the engineers, this invention might drastically cut the cost of producing green hydrogen.
“One of the major challenges of electrolysis is the high cost of electrode materials used, such as platinum or iridium,” said RMIT associate professor Amgad Rezk, who conducted the research.
“It eliminates the need for corrosive electrolytes and expensive electrodes such as platinum or iridium by making it much easier to extract hydrogen from water using sound waves. Because water is not a corrosive electrolyte, we can utilise much less expensive electrode materials like silver “Rezk explained.
According to the statement, the research has been published in Advanced Energy Material, and an Australian provisional patent application has been filed to protect the new technology.
How is electrolysis used to produce green hydrogen?
Electricity is passed through water using two electrodes to break the water molecules into oxygen & hydrogen gases. This process produces green hydrogen, which represents only a “small fraction” of global hydrogen production due to the high energy requirements.
So, how is the majority of hydrogen produced? By splitting Natural gas, often known as blue hydrogen. Greenhouse gases are emitted into the atmosphere by natural gas.
During electrolysis, the RMIT engineers used high-frequency vibrations to “divide & conquer” individual water molecules, in their experiment.
“For a given input voltage, the electrical output of electrolysis using sound waves was approximately 14 times that of electrolysis without them. This equal to the amount of hydrogen created “Yemima Ehrnst, the first author, stated.
The breakthrough is a huge step toward using the “new acoustic platform”
Ehrnst stated that the sound waves also “prevented the build-up of hydrogen & oxygen bubbles on the electrodes, which considerably increased its conductivity and stability”.
“Electrode materials used in electrolysis suffer from hydrogen and oxygen gas build-up, forming a gas layer that decreases electrode activity and drastically reduces performance,” Ehrnst, a Ph.D. researcher from RMIT’s School of Engineering, explained.
One of the lead senior researchers, Professor Leslie Yeo, stated that the discovery was a significant step toward employing the “new acoustic platform” for other applications.
“Our ability to suppress the formation of bubbles on the electrodes and quickly remove them by high-frequency vibration represents a major advance in electrode conductivity and stability. With our method, we can potentially improve conversion efficiency, resulting in a net positive energy saving of 27%,” said Yeo of the RMIT School of Engineering.
However, integrating sound wave innovations into current electrolysers to scale the work is a challenge the team needs to work on.
