Â鶹ÒùÔº

Researchers at Umeå University have identified the inner workings of a highly efficient and stable catalyst for hydrogen production, a process central to many sustainable energy initiatives.

In a recently published in the journal Communications Materials, researchers have found a way to improve catalysts for water electrolysis, which splits water into hydrogen and oxygen to generate clean fuel.

The study tackles a long-standing mystery: how can catalysts made of nickel, iron and molybdenum maintain their exceptional activity and continue to efficiently split water, even after a significant portion of their molybdenum is lost during operation.

Hydrogen is an excellent energy source, and its production from water through electrolysis forms the basis of several sustainable energy initiatives. The problem has been that the catalysts responsible for generating oxygen often wear out under harsh operational conditions, a major limitation for widespread adoption.

A catalyst that works even after losing components

For years, the activity and stability of these nickel–iron–molybdenum catalysts has been a puzzle: How could they maintain their exceptional performance even after molybdenum, a key component, washed away?

The key lies in subtle but critical changes in how the atoms are arranged. When molybdenum is present at the start, it influences how nickel and iron are positioned in the material.

"You can think of it like stretching a perfect diamond into a slightly enlarged shape. This makes it easier for the catalyst to react with water and form compounds that are important for splitting water," says Mouna Rafei, first author of the study.

Like building a stable foundation

Interestingly, even after molybdenum has disappeared, these changes in the atomic structure remain. It is like building a stable foundation: even after removing the scaffolding, the structure still stands and works as it should.

These results will guide the development of even more robust and cost-effective catalysts for water electrolysis, and may also inspire similar strategies for designing durable catalysts in other electrochemical applications.

"We were able to understand what the role of molybdenum is, and why we need it in our material even if it eventually washes away," says Eduardo Gracia, senior author of the study. "This makes us wonder if there are other, more accessible chemical elements or processes that could create similar distortions.

"Our results suggest that other materials might experience similar effects if molybdenum, or other elements, are added. In a way, this opens new routes to design entirely new types of catalysts."