PNNL

In 2021, the Department of Energy announced its Hydrogen Shot. The first Energy Earthshot targets an 80% reduction in the cost of clean hydrogen. Green hydrogen generated from water splitting will play an increasing role in an economy run on renewable resources.

However, hydrogen is challenging to store and move at large scales. As a lightweight and diffuse gas in its standard form, current storage methods require very high pressures or extremely low temperatures. These are impractical for emerging applications in transportation and long-duration energy storage.

New research at Pacific Northwest National Laboratory (PNNL) focuses on using 2-D materials to store and transport hydrogen. These materials, composed of carbon, boron, and nitrogen (CBN), are lightweight, durable, and can potentially be produced in large amounts.

The team, led by PNNL Laboratory fellow and chemist Tom Autrey, will combine expertise in materials science, surface science, theory and modeling, and hydrogen chemistry. While their previous work focused on using molecules to store hydrogen, this project will take many of the lessons learned and apply them to compositionally tailored materials.

“Researchers are working to develop a greater understanding of how to tune the structure and physical properties of 2-D materials to interact with hydrogen reversibly,” said PNNL Laboratory fellow and investigator on the project Zdenek Dohnalek. “Surface science provides an opportunity to probe and understand hydrogen behavior on supported 2-D CBN materials at an atomic scale.”

The realities of transporting and storing hydrogen require a fundamental understanding of hydrogen’s behavior. This project will look at how hydrogen gas can be added to materials and transferred from materials to carrier molecules. The eventual goal is the reversible storage of hydrogen fuel in chemical bonds.

“Developing a mechanistic understanding of hydrogen mobility and reactivity on material surfaces requires synergy between experimental work and computational studies,” said PNNL computational scientist and investigator on the project Maria Sushko. “We can gain a deeper understanding of how to control the surface interactions through a collaborative approach.”

The research will develop an understanding of how the connectivity of boron, carbon, and nitrogen in 2-D materials affects how they interact with hydrogen. The work will specifically explore how the 2-D materials activate and transport hydrogen along their surface, as well as transfer hydrogen to and from carbon-based carrier molecules. This knowledge will help the team develop design principles for new, atomically precise materials to store renewably generated hydrogen.

“The Hydrogen Shot defines an exciting goal to make green hydrogen affordable,” said Autrey. “When the community meets those targets, we need to be able to store the hydrogen in chemical bonds to impact both large scale and long duration energy storage. We want to provide the fundamental science necessary to make that a reality.”

In addition to Autrey, Dohnalek, and Sushko, PNNL investigators are Oliver Gutierrez, Nancy Washton, Bojana Ginovska, and Lili Liu. Margaret Kowalska of Columbia Basin College is also an investigator.

PNNL researchers will also play roles in other Chemical and Materials Sciences to Advance Clean Energy Technologies and Low-Carbon Manufacturing-funded projects. Kevin Rosso is the lead PNNL investigator for the “Interfacial Spectromicroscopy of Water Oxidation at Earth Abundant Solar Photoanodes” project led by Professor Franz Geiger at Northwestern University. Nancy Washton is the lead PNNL investigator for the “Direct Reduction of Metal Oxides to Metals for Electrowinning and Energy Storage” project led by Professor Paul Kempler at the University of Oregon.