Chemical Engineering

Economic hydrogen extraction from water

Researchers demonstrate how a magnetised catalyst can speed up hydrogen production while bringing down the energy cost

August 19, 2021
The Scitech

In a recent study, the researchers from the Indian Institute of Technology Bombay (IIT Bombay) have used a new catalyst for extracting hydrogen from water. Researchers have demonstrated how a magnetised catalyst can speed up hydrogen production while bringing down the energy cost. They showed that their chosen catalyst had increased the speed of producing hydrogen and reduced the energy required to do so, compared to previous studies.

To extract hydrogen from water, researchers used electrolysis of water. Earlier studies have shown that metals like Platinum, Rhodium, and Iridium speed up electrolysis. “Although these metals work well, industrial systems don’t prefer them because they are expensive,” says Prof Chandramouli Subramaniam of IIT Bombay and an author of the study. The study has used a compound consisting of cobalt and oxygen to achieve the same goal at a much lower cost.

To achieve the increased energy efficiency, the researchers turned to less costly metal cobalt, already known for speeding up electrolysis. They decorated carbon nanoflorets, nanocarbon structures arranged like a marigold flower with cobalt oxide particles and placed these nanoflorets in the water. An electric field applied through the cobalt oxide to water molecules results in the electrolysis of water. Although cobalt oxide is a well-known electrochemical catalyst, it requires a high amount of energy and produces hydrogen at a low speed. To increase the speed of electrolysis, the researchers did not rely on the electric field alone. Magnetic fields, which are related to electric fields, can play a crucial role in these reactions. The researchers showed that if they introduced a small fridge magnet near their setup, the reaction speed increased about three times. Even after removing the external magnet, the reaction still took place about three times faster than in the absence of the magnetic field. It is easy to integrate accessible house-magnets into the existing designs at a low cost. “We can directly adopt the modified setup in existing electrolysers without any change in design or mode of operation of the electrolysers,” says Ranadeb Ball, another author of the study. “The intermittent use of an external magnetic field provides a new direction for achieving energy-efficient hydrogen generation. Other catalysts can also be explored for this purpose,” says Prof. Subramaniam. The research was published in the journal ACS Sustainable Chemistry & Engineering.

Source: India Science wire