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open-doi-10.1073/pnas.2101817118

A new approach creates an exceptional single-atom catalyst for water splitting [stanford.edu]:

To make the new catalyst, researchers first made a porous structure to support the iridium atoms that would catalyze the reaction.

They exposed this foam-like structure to a solution containing iridium compounds, quickly froze it to create a thin, iridium-rich layer of ice on the surface, and did additional processing to create well-distributed sites where individual iridium atoms were snugly anchored on the supportive surface.

X-ray observations of the catalyst at work revealed that the iridium atoms were in a chemical state that makes them exceptionally effective in carrying out the part of the water-splitting reaction that releases oxygen.

Other tests showed that this enhanced activity was due entirely to the fact that the iridium was in the form of single, isolated atoms, and not just to the large surface area on which they were embedded.

The resulting catalyst is better than most of the iridium-based catalysts known to date, the researchers reported. They said this new atom-anchoring system provides an ideal model for probing and establishing the connection between catalysts and their support structures for a variety of electrocatalytic reactions.

Yi Cui is an investigator with the Stanford Institute for Materials and Energy Sciences (SIMES) at SLAC, and Michal Bajdich is an investigator with the SUNCAT Center for Interface Science and Catalysis, a SLAC/Stanford joint institute where theoretical calculations were carried out. X-ray observations of the catalyst were carried out at SLAC’s Stanford Synchrotron Radiation Lightsource (SSRL) and Lawrence Berkeley National Laboratory’s Advanced Light Source (ALS), and computational work was performed at the National Energy Research Scientific Computing Center (NERSC); all three are DOE Office of Science user facilities. Researchers from The Molecular Foundry at Berkeley Lab and the Material Measurement Facility at the National Institute of Standards and Technology also contributed to this work, which was funded by the DOE Office of Science.

Citation: Xueli Zheng et al., Proceedings of the National Academy of Sciences, 31 August 2021 (10.1073/pnas.2101817118 [pnas.org])

For questions or comments, contact the SLAC Office of Communications at communications@slac.stanford.edu [mailto].

SLAC is a vibrant multiprogram laboratory that explores how the universe works at the biggest, smallest and fastest scales and invents powerful tools used by scientists around the globe. With research spanning particle physics, astrophysics and cosmology, materials, chemistry, bio- and energy sciences and scientific computing, we help solve real-world problems and advance the interests of the nation.

SLAC is operated by Stanford University for the U.S. Department of Energy’s Office of Science [energy.gov]. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time.

Original Submission