Hydrogen has been proposed as an alternative to fossil fuels, for example in the shipping and aviation industries. However, the production of hydrogen is generally not very environmentally friendly and is marked by high energy loss.
So-called ‘green’ hydrogen is produced by electrolysis of water using renewable energy, but this is currently much more expensive than traditional production methods.
Yukihiro Takahashi, a PhD candidate at the Norwegian University of Science and Technology (NTNU), has investigated how production can be made cheaper, more efficient and less time-consuming.
Nickel coating
The most common technology for producing ‘green’ hydrogen is alkaline water electrolysis (AWE). This method requires a nickel coating for both corrosion protection and catalytic activity. (A catalyst is a substance that increases the rate of a chemical reaction without being consumed itself.)
This nickel coating is usually produced by electroplating, where electricity is used to apply the coating to a substrate. However, if the distribution of electricity is uneven, the coating will also be uneven, resulting in material waste and higher costs.
In order to reduce costs and waste, it is therefore crucial to have good control over the electroplating process.
Produced more even coatings
This process is precisely what Takahashi has been working on. He has studied so-called complexing agents that can inhibit excessive nickel growth and provide more even and more effective coatings.
In addition, he has developed mathematical models to describe and optimize the method.
He analyzed the effect of complexing agents both experimentally and theoretically, focusing on pH changes, current efficiency and uniform thickness.
The result is a model that can predict the results of electroplating even when other additives are included. These can also be transferred to other complex electrochemical processes.