X-ray beams help researchers learn new tricks from old metals

A research team led by the U.S. Department of Energy’s (DOE) Argonne National Laboratory used powerful X-ray beams to unlock a new understanding of materials important to the production and use of hydrogen. The goal is to make hydrogen production and usage more efficient and less expensive, offering a better fuel for transportation and industry.

“Efficient hydrogen production is key,” said Hoydoo You, an Argonne senior physicist. ​“Hydrogen is the lightest energy storage material. Hydrogen can be produced from water using renewable energy or excess energy, transported as a fuel, and converted back to water to produce energy for consumers. Platinum and its alloys are best in catalyzing and boosting the water-splitting process by accelerating the exchange of electrons.”

Understanding and developing materials enabling efficient production and usage of hydrogen are key to the hydrogen economy. The researchers made a first step in developing a tool that enables them to characterize the materials with a new level of detail, ultimately producing the best materials for hydrogen production and use.

“This will make production and use of hydrogen less costly and more environmentally friendly,” You said.

The research team made use of the Advanced Photon Source (APS), a DOE Office of Science user facility at Argonne. Working at the APS, researchers aimed an intense X-ray beam onto a single grain of platinum. Diffraction patterns from that grain were collected on an X-ray detector. Those patterns were converted into images of the sample using customized computer algorithms.

“Hydrogen is the lightest energy storage material. Hydrogen can be produced from water using renewable energy or excess energy, transported as a fuel and converted back to water to produce energy for consumers. Platinum and its alloys are best in boosting the conversions.” — Hoydoo You, Argonne National Laboratory

A nanodroplet chemical cell, created with a tiny pipette tip (a tool for making a small droplet of liquid), was used to control the chemical reaction happening on the platinum grain to produce hydrogen in an electrolyzer. An electrolyzer is a device for producing hydrogen fuel from water using electricity; the device in a reverse operation, known as a fuel cell, converts hydrogen fuel back to electricity.

“The reaction was controlled by applying voltage, directed through an electrolyte in the nano-pipette onto the grain being studied,” said Argonne physicist Matt Highland. He designed the initial prototype of this new tool. This prototype enabled the investigation of a single nanograin and opened a door for scanning capability over all grains in a realistic electrolyzer or fuel cell when the APS upgrade is completed. He also helped with the data collection and experiments.

Argonne physicists Ross Harder and Wonsuk Cha worked at the APS beamline 34-ID-C, where the experiments were performed, and helped with integrating the new electrochemistry tool in the existing instrument.

“The ability to do localized electrochemistry while creating a new picture of the way things were happening, at a single particle level, was incredible,” Harder said.

The APS currently delivers X-ray beams that are up to a billion times brighter than those used by a dentist. But an extensive upgrade will make the APS even more powerful. When the upgraded APS comes online in 2024, its X-ray beams will be up to 500 times brighter than today. This means that techniques like the one used in this research will get even better after the upgrade.

“The APS upgrade will help us see things happen in real time in the material,” said Harder. ​“Measurement times could become fast enough that we can move from one particle to another, and we could see how they are interacting with the electrochemical environment and each other.” 

“Important processes like battery charging and corrosion require the real-time imaging of grains to understand a full picture of the process,” said Argonne assistant physicist Dina Sheyfer. ​“We believe the added brightness of the APS upgrade with our new tool will enable studies we can only dream about today.” 

A paper based on the study was published in American Chemical Society’s Nano Letters. Co-authors are Sheyfer, Highland, Harder, Cha and You with Argonne’s Stephan O. Hruszkewycz and former Argonne scientist Tomoya Kawaguchi (Tohoku University). Other contributors include Stanford University’s Ruperto G. Mariano and Matthew W. Kanan.

Funding for this research came, in part, from the DOE Office of Basic Energy Sciences, Materials Sciences and Engineering Division and the Scientific User Facilities Division.

About the Advanced Photon Source

The U. S. Department of Energy Office of Science’s Advanced Photon Source (APS) at Argonne National Laboratory is one of the world’s most productive X-ray light source facilities. The APS provides high-brightness X-ray beams to a diverse community of researchers in materials science, chemistry, condensed matter physics, the life and environmental sciences, and applied research. These X-rays are ideally suited for explorations of materials and biological structures; elemental distribution; chemical, magnetic, electronic states; and a wide range of technologically important engineering systems from batteries to fuel injector sprays, all of which are the foundations of our nation’s economic, technological, and physical well-being. Each year, more than 5,000 researchers use the APS to produce over 2,000 publications detailing impactful discoveries, and solve more vital biological protein structures than users of any other X-ray light source research facility. APS scientists and engineers innovate technology that is at the heart of advancing accelerator and light-source operations. This includes the insertion devices that produce extreme-brightness X-rays prized by researchers, lenses that focus the X-rays down to a few nanometers, instrumentation that maximizes the way the X-rays interact with samples being studied, and software that gathers and manages the massive quantity of data resulting from discovery research at the APS.

This research used resources of the Advanced Photon Source, a U.S. DOE Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357.

Argonne National Laboratory seeks solutions to pressing national problems in science and technology. The nation’s first national laboratory, Argonne conducts leading-edge basic and applied scientific research in virtually every scientific discipline. Argonne researchers work closely with researchers from hundreds of companies, universities, and federal, state and municipal agencies to help them solve their specific problems, advance America’s scientific leadership and prepare the nation for a better future. With employees from more than 60 nations, Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science.

The U.S. Department of Energy’s 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. For more information, visit https://​ener​gy​.gov/​s​c​ience.