A group led by Robert Wexler, assistant professor of chemistry, is pursuing an exciting new path toward sustainable energy.
A multi-institutional group led by Robert Wexler, assistant professor of chemistry, has received a $1.25 million grant from the U.S. Department of Energy to design materials that can harness solar thermal energy to produce hydrogen fuel from water. The funding is part of the Biden administration’s Hydrogen Shot initiative to reach net-zero carbon emissions by 2050. “WashU and our department are working to play an important role in the transition to sustainable energy,” Wexler said.
Wexler and his team — including researchers at Arizona State University, The Ohio State University, the National Renewable Research Laboratory, and Sandia National Laboratories — have created a crystalline material that could form the foundation for new clean-energy technologies. As described in the journal Energy and Environmental Science, the novel material combines five elements: calcium, cerium, titanium, manganese, and oxygen.
While each element is important, oxygen is especially crucial. When heated by the sun, the material will release oxygen molecules. As it cools, it will want to reclaim that oxygen. But if the material comes into contact with steam, it regains that oxygen by breaking the bonds in H2O. That reaction would create hydrogen gas that could be used as a fuel.
Wexler, who was hired as a part of Dean Feng Sheng Hu's Digital Transformation Initiative in Arts & Sciences, discovered and tested the materials on his computer, an approach that lets researchers virtually study many different combinations of elements without the expense and effort of synthesizing and characterizing the compounds in a lab. If a combination seems promising in the virtual world, chemists elsewhere can make it a reality.
The exciting aspect of this new material — a novel variation on materials called “perovskites” that are also used in solar panels — is that it gives up its oxygen with relative ease. With a little help, simple sunlight can do the trick. “We focus sunlight with mirrors, and we basically use that heat to cook the material,” Wexler said.
Any technology that could create hydrogen fuel using sunlight would greatly advance the quest for sustainable energy, said Wexler, who earlier this year co-authored a book chapter on using solar power to split water molecules. “If we can find renewable ways to make the material and the furnace in the first place, then we would be completely carbon neutral,” Wexler said. He added that hydrogen has many other uses that go beyond fuel, including the industrial production of pharmaceuticals and other chemicals.
Still, much work remains. Researchers will use the Department of Energy funding to perfect the material, study its properties, and figure out the most efficient ways to produce and capture hydrogen fuel.
“There's not going to be one technology that enables the sustainable energy transition,” Wexler said. “It’s going to be a collective effort of different technologies. I’m excited to be contributing.”
