Hunt for cheap metals that help store sustainable energy
Storing energy is one of the biggest challenges in the energy transition. Hydrogen could be a solution. Chemist Daan den Boer is researching how to make the chemical reaction needed to store energy in hydrogen as cheap and efficient as possible.
By 2050, the Netherlands wants almost all its energy to come from sustainable sources such as the sun and wind. If it’s very windy or sunny, surplus electricity can be generated. This no longer fits on the grid and has to be stored somewhere. Then it can be used at times when there is little sun or wind. Hydrogen is seen as a potential solution for storing this surplus energy. This chemical element can store a lot of energy and is a cheaper and easier form of energy storage than batteries.
Cheap and efficient hydrogen storage
To store the surplus energy, electricity is used to split water into hydrogen and oxygen. This process is called electrolysis. The hydrogen can then be stored in empty gas fields or salt caverns. When the hydrogen is burned, the energy is released again along with water as the only by-product. No greenhouse gases are released.
To accelerate the chemical reactions required for this, you need catalysts made from metals. Den Boer conducts research into a catalyst that can help produce hydrogen as cheaply and efficiently as possible. ‘The bottleneck in the electrolysis process is mainly in the conversion of water to oxygen. That is a complex reaction, which makes it difficult to find a suitable catalyst.’
At present, most catalysts for converting water to oxygen are based on iridium. ‘That is one of the most expensive metals in the world because it is very rare,’ Den Boer explains. ‘I am researching whether we can’t use cheaper metals like copper, nickel or cobalt instead of this expensive metal.
To put it simply, he is looking in the lab at what happens if he passes electricity through different catalysts. ‘I’m also researching the reaction process, why certain metals make a reaction work and whether we can improve this. It’s fundamental research in which you keep coming up against new limitations. And it’s going to take years. What we’re researching may not become relevant in practice for another 30 years.’
Text: Dagmar Aarts