Nanocubes as optimal catalysts
For the production of green hydrogen to gain momentum, one thing above all is needed: nanoparticles that act as catalysts to control the process of splitting water into oxygen and hydrogen. The particles should be inexpensive, effective and environmentally compatible – and cube-shaped. This is what researchers from the UDE and the Ruhr University Bochum (RUB) have now discovered. Their proof that cube-shaped nanoparticles are much more effective than spherical ones paves the way for the targeted design of efficient catalysts for green hydrogen. They reported on their findings in the scientific journal Advanced Functional Materials*.
Precious metals such as platinum or iridium are rare and expensive, but so far they are the most effective catalysts for the production of green hydrogen. A team led by Prof. Dr. Kristina Tschulik (RUB) and Prof. Dr. Rossitza Pentcheva (UDE) have set themselves the task of changing that. In the researchers’ focus: Oxide nanoparticles made of base metal, such as cobalt oxide. They come into question as catalysts for the half-reaction of water splitting, namely for the formation of oxygen. “Oxygen evolution as a partial reaction of the so-called water electrolysis is much more complex than hydrogen evolution and thus represents a bottleneck effect for the production of green hydrogen ” says Pentcheva.
The team around Kristina Tschulik has developed a method to analyze individual particles directly in solution. This makes it possible to compare the activity of different nanomaterials with each other and thus elucidate the influence of particle properties, such as their shape and composition, on water splitting. The result: the surface of cube-shaped cobalt oxide nanoparticles is much more active in the formation of oxygen than the surfaces of their spherical counterparts.
Through quantum mechanical simulations, including on the supercomputer at UDE, Rossitza Pentcheva’s team provides an explanation for the phenomenon and a deeper insight into the underlying mechanism: the higher catalytic activity of the cubic nanoparticles compared to the spherical ones is due to the different active sites on the two surfaces. “Understanding at the atomic level how the crystallographic orientation of the surface and the catalytic activity are related is the basis for the targeted design of new catalysts,” physicist Pentcheva says.
- To original publication: https://onlinelibrary.wiley.com/doi/10.1002/adfm.202370006
Prof. Dr. Rossitza Pentcheva, Tel. 0203 379 2238, firstname.lastname@example.org
Go to UDE press release