New imaging technique reveals microscopic networks behind catalyst reactions

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Scientists from the University of Warwick and the Massachusetts Institute of Technology have directly observed how microscopic networks on catalyst surfaces coordinate chemical reactions, challenging long standing assumptions about how catalysts function. The discovery could accelerate the development of cleaner fuels and energy technologies.

The findings, published this week in the journal Nature Catalysis, rely on an advanced technique known as scanning electrochemical cell microscopy. This approach allowed researchers to map the activity of a platinum catalyst with unprecedented detail, providing a new view of how chemical reactions occur on its surface.

For decades, scientists believed catalysts operated through isolated “hot spots”, small areas where reactions occurred more rapidly than elsewhere on the surface. The new study shows a different picture. Instead of isolated sites, the catalyst behaves like an interconnected electrical network where different regions share electrons and work together to drive chemical reactions.

Dr. Xiangdong Xu, a chemistry researcher at the University of Warwick and the study’s lead author, explained that the catalyst surface acts more like a connected system than a collection of independent sites. According to the research team, various regions communicate through electron flow, enabling the overall reaction to proceed more efficiently.

The researchers focused on thermochemical reactions linked to fuel production and clean energy technologies, including hydrogen generation. By combining scanning electrochemical cell microscopy with crystallographic mapping, the team discovered that individual crystal grains on the catalyst surface specialize in different chemical steps.

Some grains were found to promote oxidation reactions, while others favored reduction processes. Despite these distinct roles, the regions function cooperatively through electron exchange, forming a coordinated system that enhances overall catalytic activity.

The study also revealed what researchers described as chemical interactions between neighboring regions. Reactions occurring in one part of the surface can influence nearby areas, sometimes strengthening catalytic performance and sometimes suppressing it.

Dr. Yogesh Surendranath, an associate professor at MIT and co author of the research, said the results challenge the traditional view that catalyst surfaces are simply a patchwork of independent active sites. Instead, the interactions between regions appear to play a crucial role in determining the efficiency of the entire system.

These insights suggest a new strategy for designing next generation catalysts. Rather than focusing only on improving individual active sites, scientists may seek to engineer catalyst surfaces where interactions between regions are deliberately controlled.

Professor Pat Unwin of the University of Warwick said the discovery opens the possibility of designing catalysts that exploit these regional interactions to improve performance. Such advances could benefit sustainable manufacturing, environmental remediation and the development of cleaner energy technologies.