Hydrogen could play a key role in the energy transition. But to produce it from water in a climate-friendly way, we need catalysts that are not only efficient but also durable. Jasmin Finkelmeyer and Martin Presselt, together with a team from the University of Illinois Chicago, have investigated a new material combination that could make this possible.

Catalysts are essential for the electrochemical splitting of water. They ensure that water molecules are efficiently broken down into their components, oxygen and hydrogen. However, many of the catalysts used so far are based on rare metals such as platinum and are prone to decomposition or agglomeration in solution. “Our goal is to find more sustainable alternatives,” says PD Dr. Martin Presselt. “With our highly sensitive measurements and in collaboration with the team led by Prof. Dr. Ksenija Glusac from the University of Illinois Chicago, we contributed to a better understanding of the stability and electronic properties of the materials.”

The researchers combined graphene nanoribbons – ultrathin carbon structures – with a rhodium-based catalyst. “The idea initiated by the Glusac group was to couple catalyst molecules to a conductive structure that improves their stability and electronic properties. We helped analyze the interactions in more detail using exceptionally sensitive measurements,” explains Dr. Jasmin Finkelmeyer. “Graphene nanoribbons are particularly suitable for this because they are electrically conductive and chemically robust.”

It was indeed shown that the binding to graphene prevented the catalyst molecules from aggregating, which preserved their activity in the long term. Moreover, the nanoribbons enabled a controlled electron distribution, making the catalyst more efficient.

Finding the Right Balance

One key advantage: The new material remains stable across a wide pH range. While many catalysts are only effective in strongly acidic or alkaline solutions, the combination studied here also remains active under neutral conditions.

“That makes the technology more versatile,” says Martin Presselt.

However, the design must be precisely tuned. “If a material is poorly designed, relaxation processes occur faster than the actual chemical reactions we aim to drive,” explains Martin Presselt. “So we have to find exactly the right balance between electronic coupling and reactivity.”

A Step Toward Sustainable Hydrogen

Hydrogen production faces the challenge of becoming more efficient and cost-effective. A stable, high-performance catalyst could help make electrolyzers more durable – and thereby, in the long term, make the production of green hydrogen more economical.

“The study shows that the choice of support material has a major impact on catalyst performance,” says Jasmin Finkelmeyer. “The research team has found a promising approach here that we now want to further develop.”

CataLight: Collaborative Research for New Catalysts

The study was conducted within the Collaborative Research Center CataLight, a partnership between the universities of Jena and Ulm along with other partners. The research network investigates how light-driven catalytic processes can be optimized – inspired by natural photosynthesis. “We don’t just want to improve individual catalysts but also gain a better understanding of the fundamental principles of material development,” says Martin Presselt. “Our goal is to find sustainable alternatives to existing systems.”