Chemical Reactions Observed at Atomic Level
New technology lets scientists visualize chemical reactions at the atomic scale, capturing molecules in motion like never before. This image is partially 3D-rendered. (paulista/Shutterstock)
In a nutshell
- Scientists have developed a powerful new microscope called SMART-EM that can record real-time videos of individual atoms and molecules during chemical reactions, something that was previously impossible.
- Using this technology, researchers directly observed how alcohol molecules transform into hydrogen fuel on a catalyst’s surface, revealing never-before-seen intermediate steps in the reaction process.
- These insights could lead to the design of more efficient catalysts for producing clean hydrogen, potentially making green energy and sustainable manufacturing more affordable and scalable.
EVANSTON, Ill. — The chemical industry powers modern life, from fertilizers to pharmaceuticals, but much of what happens at the atomic level during catalytic reactions has remained invisible—until now. Scientists have developed a microscope that films individual atoms rearranging during reactions, revealing hidden details that could transform how we produce clean energy and sustainable materials.
The technology, called Single-Molecule Atomic-Resolution Time-resolved Electron Microscopy (SMART-EM for short), lets scientists observe individual atoms and molecules as they interact during chemical reactions. The study, published in the scientific journal Chem, explains how this was possible.
“Since 2007, physicists have been able to realize a dream over 200 years old — the ability to see an individual atom,” says the inventor of SMART-EM Eiichi Nakamura, in a 2019 statement. “But it didn’t end there. Our research group has reached beyond this dream to create videos of molecules to see chemical reactions in unprecedented detail.”
Researchers used this powerful technique to study how catalysts help produce hydrogen, a promising clean fuel that could one day help reduce our dependence on fossil fuels. What they saw is changing how we understand these important chemical processes.
The breakthrough represents a quantum leap in our ability to observe molecular reactions. Traditional methods only provide static images or data about millions of molecules at once, but SMART-EM allows scientists to watch individual molecular transformations happening in real-time.
Catalysts are essential to modern life. These special substances speed up chemical reactions without getting used up themselves. They are behind the production of fertilizers, plastics, medicines, and countless other products we rely on daily. In fact, more than three-quarters of all industrial chemical processes use catalysts in some way.
The problem? Scientists have struggled to understand exactly how catalysts work at the atomic level; they’re just too small to see with conventional methods. That’s where this new microscope technology comes in.
The research team from Northwestern University and the University of Tokyo focused on a special type of catalyst that could help produce clean hydrogen from renewable alcohols (which can be made from plant materials). Using their advanced microscope, they recorded videos of individual molecules reacting on the catalyst surface.
This approach is completely different from traditional methods. Usually, scientists study millions of molecules at once and get an average picture, like trying to understand traffic patterns by looking at a blurry aerial photo. With SMART-EM, researchers can follow individual “cars” on the molecular highway, seeing exactly where they go and how they behave.
When alcohols interact with the catalyst, they form temporary structures that transform step-by-step before producing hydrogen. The team identified previously unknown intermediate compounds that play crucial roles in the reaction, including a “hemiacetal complex” and “aldehyde oligomers,” which are basically specific arrangements of atoms that form temporarily during the reaction.
The researchers were able to observe these molecular transformations that would be impossible to see using other techniques. This direct visual evidence helped them understand the entire reaction pathway from beginning to end.
“This is a big breakthrough,” says study author Yosi Kratish from Northwestern University. “SMART-EM is changing the way we look at chemistry. Eventually, we want to isolate those intermediates, control the amount of energy we put into the system, and study the kinetics of a live organic catalytic transformation. That will be phenomenal. This is just the beginning.”
Scientists have opened a window into a previously invisible world. The research combines cutting-edge microscopy with computational modeling and other analytical techniques to build a comprehensive picture of what’s happening during these reactions. This detailed view could help scientists design better catalysts, ones that work more efficiently and with less waste. Better catalysts could mean more affordable clean energy, less pollution, and more sustainable chemical manufacturing.
Paper Summary
Methodology
Researchers used a specialized microscope technique (SMART-EM) that can film individual molecules reacting. They created a catalyst by attaching molybdenum oxide to carbon nanohorns (tiny carbon structures) and watched how different alcohols interacted with this catalyst. The team recorded videos at up to 50 frames per second using a high-powered electron microscope. To confirm what they were seeing, they also used computer simulations and several other analytical techniques like X-ray spectroscopy to verify the structures and energy requirements of the reactions they observed.
Results
The team successfully captured videos showing four key stages in the process of converting alcohols to hydrogen. They observed how alcohols first attach to the catalyst, then transform through several intermediate steps before producing hydrogen. Most importantly, they discovered previously unknown intermediate structures that form during the reaction, including a particular arrangement of atoms (a hemiacetal complex) and the formation of chains of molecules still attached to the catalyst. These observations revealed a new reaction pathway that requires less energy than previously thought. The study showed that hydrogen production becomes energetically favorable when coupled with a polymerization process that happens simultaneously.
Limitations
The camera speed currently limits the ability to capture the fastest molecular movements. The technique also requires very specialized equipment and expertise that isn’t widely available. Some aspects of the molecular structures showed minor differences between what was observed and what computer simulations predicted. Since the study focused on a specific type of molybdenum catalyst, the findings might not apply exactly the same way to other catalytic systems without additional research.
Funding and Disclosures
The research was funded primarily by the U.S. Department of Energy’s Office of Science and Basic Energy Sciences, with additional support from Northwestern University facilities, NASA Ames Research Center, and Argonne National Laboratory. The researchers declared no competing financial interests in the study.
Publication Information
The study, “Atomic-Resolution Imaging as a Mechanistic Tool for Studying Single-Site Heterogeneous Catalysis,” was published in the scientific journal Chem. The research team included scientists from Northwestern University, Argonne National Laboratory, and the University of Tokyo, led by Yosi Kratish and Tobin J. Marks.
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