At the atomic scale, something astonishing is happening in the laboratories of the University of Nottingham: platinum and nickel atoms are dancing. They start mixed together in tiny nanoscale particles containing only a few dozen atoms. Within seconds, under the gaze of an electron microscope, they separate from one another—a process that shouldn't happen according to the laws of thermodynamics, yet it does. And when they part ways, something remarkable emerges: a record-breaking catalyst for green hydrogen production.
This discovery matters because hydrogen is poised to be a cornerstone of the global clean energy transition, yet producing it efficiently remains a critical challenge. Traditional methods rely on fossil fuels. Green hydrogen, made by splitting water through electrochemical means, offers a pathway to clean fuel—but only if we can find better catalysts to make the process efficient and affordable. The breakthrough from Nottingham, developed in collaboration with the University of Birmingham, Diamond Light Source, and Ulm University in Germany, opens a new frontier in catalyst design.
Dr. Emerson Kohlrausch, who led the experimental work, watched this atomic drama unfold in real time using electron microscopy. "Initially, when we looked at the platinum-nickel nanoparticles under the electron microscope, we saw that the two types of atoms are mixed, as one would expect in an alloy. However, only a few seconds later, the two metals started to separate from each other in front of our eyes." The separation works because the electron beam used for imaging actually stimulates the atoms to reshuffle and find new positions. As the nickel separates from the platinum, it picks up oxygen atoms from the environment, forming an oxide. The result is an elegant hybrid particle—platinum metal on one side, nickel oxide on the other, divided by an atomically defined interface that becomes extraordinarily active for water splitting.
What makes this genuinely revolutionary is the reversibility. The metals can be mixed together again if conditions change, reforming the alloy. The same process can be repeated many times. Rather than treating particles as static, unchanging objects, the researchers recognized them as dynamic systems capable of adapting to their environment. "Rather than behaving like rigid solid objects, the particles appeared to behave like living creatures, responding to the environment," Kohlrausch reflected. "This inspired us to harness their dynamics for catalysis."
The team tested these adaptive particles for hydrogen production and discovered that the metal separation observed in the microscope also occurs under actual reaction conditions. The magic lies in cooperation: platinum and nickel oxide each perform different roles in the water-splitting process, and sharing that atomic boundary enables extraordinary collaboration between them. Dr. Jesum Alves Fernandes, who led the project from Nottingham's School of Chemistry, explains: "What makes this discovery exciting is that we can reversibly tune the structure of the particle while directly observing the process at the atomic scale. This opens a new strategy for designing adaptive catalysts for a wide range of applications."
The implications extend far beyond hydrogen. By learning to harness atomic motion and reversible restructuring, scientists can now design catalysts that actively adapt to their working conditions—a principle that could transform everything from energy storage to chemical manufacturing. The research, published in Advanced Materials, represents not just an incremental improvement but a fundamental shift in how we think about catalysis.