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Catalysts play an essential yet often overlooked role in our daily lives, facilitating processes ranging from baking bread to creating fuels more effectively. Researchers at SLAC National Accelerator Laboratory have recently made strides in accelerating the discovery of a novel category of these substances known as single atom catalysts.
For many years, catalysts have quietly empowered numerous industrial and household applications by transforming raw materials into various products or fuels with reduced energy expenditure. Examples include natural catalysts like yeast in bread making and synthetic catalysts designed to convert feedstocks into energy sources efficiently and sustainably. A significant focus in this field is understanding single atom catalysts, which researchers are investigating to determine how the specific structure of their active sites affects their catalytic performance.
In a groundbreaking development, scientists from the Stanford Synchrotron Radiation Lightsource (SSRL) at SLAC collaborated with the University of California, Davis (UC Davis) team to create a new software tool aimed at providing detailed structural insights into the active sites of single atom catalysts. This advancement has the potential to significantly reduce the time required for such analyses compared to existing methodologies. The researchers published their findings in Chemistry-Methods.
Traditionally, catalysts rely on inert materials to support clusters of metal atoms, with only the surface atoms participating in reactions while the inner atoms remain inactive. To enhance the efficiency of metal atom usage, scientists have proposed single atom catalysts, where isolated metal atoms are uniformly distributed on a support material.
A comprehensive understanding of the structure of these active sites is crucial for optimizing catalyst performance. Researchers focused on single platinum atoms on a magnesium oxide support as a model system for their studies. Lead author Rachita Rana, who recently completed her PhD at UC Davis, applied extended X-ray absorption fine structure (EXAFS) spectroscopy to gain insights into the atom’s local environment, examining factors like the count and arrangement of surrounding atoms. Traditionally, evaluating EXAFS data involves analyzing numerous potential structures before arriving at an optimal fit. Rana’s innovative approach integrated theoretical computations, specifically density functional theory, with EXAFS to streamline the analysis process. The initial version of their software, QuantEXAFS, successfully defined structures for platinum atoms.
Recognizing that real-world catalysts often comprise both single atoms and nanoparticle clusters, Rana enhanced QuantEXAFS to analyze the proportions of these forms, yielding more precise structural data. “MS-QuantEXAFS not only assists in identifying active sites but also quantifies the presence of specific configurations while automating the data analysis,” she explained. “Manually conducting this analysis could take days or even months; however, with the new software, the process could be completed overnight on a standard computer.”
The research team aims to make MS-QuantEXS available to the broader scientific community, seeing significant potential for its application among catalysis researchers. Co-author Simon R. Bare, a Distinguished Scientist at SSRL, echoed this sentiment and expressed interest in incorporating the tool into educational programs for future scientists.
This research was supported by the DOE Office of Science, with SSRL operating as a user facility within the DOE framework.
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