A switchable catalyst for cleaner hydrogen: greater efficiency and longer lifespan

A research team at CiQUS (University of Santiago de Compostela) has developed a new catalytic material that can be switched on and off at will — a breakthrough that could significantly extend the lifetime of hydrogen production systems and make the process more efficient and sustainable.

Producing green hydrogen through water electrolysis — using electricity to split water into hydrogen and oxygen — is one of the most promising routes to clean energy. However, the materials that drive this reaction (called electrocatalysts) often degrade quickly with use. As their activity decreases over time, systems become less efficient and more expensive to operate.

To address this challenge, researchers at the Centre for Research in Biological Chemistry and Molecular Materials (CiQUS) have designed a novel hybrid catalyst that can toggle between an active and a resting state through simple electrical adjustments, much like a switch. Their work has been published in the journal Advanced Science.

The new material consists of tiny palladium nanoparticles embedded inside hollow carbon nanofibers. These tubular structures are not only protective — preventing the particles from clumping together and degrading — but also play an active role in the switching mechanism.

The key innovation lies in the controlled and reversible activation of the catalyst. By introducing sulfur into the system, the researchers created a dynamic chemical environment where the catalyst can transition between two states. In its active mode, it efficiently promotes hydrogen production. When inactive, it is effectively “paused” — shielded from processes that would otherwise reduce its effectiveness over time.

“We’ve developed a catalyst that can be turned on or off as needed,” explains CiQUS researcher María Giménez López, who led the study. “This opens the door to smarter, more durable systems for industrial hydrogen production.” The switching process is fully reversible. The catalyst can be reactivated by applying a specific electrical signal, restoring its hydrogen-generating ability. This enables on-demand control, increasing the material’s useful life and making better use of valuable resources like palladium.

Beyond this specific system, the researchers believe that the strategy could be applied to other types of catalysts and reactions. “Our findings show that it’s possible to improve catalyst longevity without compromising performance,” adds Giménez López. “This could make a real impact in clean energy technologies.”

The research was supported by CiQUS, which receives funding from the European Union through the Galicia ERDF Programme 2021–2027 — a key driver behind the development of this work.