A clean energy future propelled by hydrogen fuel depends on figuring out how to reliably and efficiently split water. That’s because, even though hydrogen is abundant, it must be derived from another substance that contains it — and today, that substance is often methane gas. Scientists are seeking ways to isolate this energy-carrying element without using fossil fuels. That would pave the way for hydrogen-fueled cars, for example, that emit only water and warm air at the tailpipe.
Water, or H2O, unites hydrogen and oxygen. Hydrogen atoms in the form of molecular hydrogen must be separated out from this compound. That process depends on a key — but often slow — step: the oxygen evolution reaction (OER). The OER is what frees up molecular oxygen from water, and controlling this reaction is important not only to hydrogen production but a variety of chemical processes, including ones found in batteries.
“The oxygen evolution reaction is a part of so many processes, so the applicability here is quite broad.” — Pietro Papa Lopes, Argonne assistant scientist
A study led by scientists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory illuminates a shape-shifting quality in perovskite oxides, a promising type of material for speeding up the OER. Perovskite oxides encompass a range of compounds that all have a similar crystalline structure. They typically contain an alkaline earth metal or lanthanides such as La and Sr in the A-site, and a transition metal such as Co in the B-site, combined with oxygen in the formula ABO3. The research lends insight that could be used to design new materials not only for making renewable fuels but also storing energy.
Read more at DOE/Argonne National Laboratory
Image: The unique interactions between perovskite oxide, its changing surface layer, and iron species that are active toward the OER paves a new path for the design of active and stable materials, bringing us one step closer to efficient and affordable green hydrogen production. (Credit: Argonne National Laboratory)