Hydrogen may be created cleanly with considerably better efficiency and at a lower cost than is now achievable with commercially available catalysts, according to Oregon State University study into catalyst design.
A catalyst is a material that speeds up a chemical reaction without changing its chemical properties permanently.
“The findings are significant because the production of hydrogen is important for many aspects of our life, such as fuel cells for cars and the manufacture of many useful chemicals such as ammonia,” said the OSU College of Engineering’s Zhenxing Feng, a chemical engineering professor who led the research. “It’s also used in the refining of metals, for producing human-made materials such as plastics and for a range of other purposes.”
According to Feng, obtaining hydrogen from natural gas via a carbon-dioxide-producing process known as methane-steam reforming is cleaner and more sustainable than the traditional technique of deriving hydrogen from natural gas via a carbon-dioxide-producing process known as methane-steam reforming.
However, the higher expense of the greener method has proven to be an impediment in the business. The new findings were reported in Science Advances and JACS Au, and detail novel techniques to construct catalysts that can considerably improve the efficiency of the clean hydrogen production process.
Catalysts frequently undergo structural changes while facilitating reaction processes, according to Feng. The changes can be reversible or irreversible, and irreversible restructuring is thought to degrade a catalyst’s stability, resulting in a loss of catalytic activity and a reduction in reaction efficiency.
Catalysts are critical to promoting the water-splitting reaction by lowering the overpotential, and thus lowering the total cost for hydrogen production.
Zhenxing Feng
Feng, Maoyu Wang, an OSU Ph.D. student and collaborators researched the reorganization of catalysts in reaction and then modified their surface structure and composition at the atomic level to produce a highly efficient catalytic process for hydrogen production.
An active phase of an amorphous iridium hydroxide catalyst had 150 times the efficiency of its initial perovskite structure and was close to three orders of magnitude better than iridium oxide, a common commercial catalyst.
“We found at least two groups of materials that undergo irreversible changes that turned out to be significantly better catalysts for hydrogen production,” Feng said. “This can help us produce hydrogen at $2 per kilogram and eventually $1 per kilogram. That’s less expensive than the polluting process in current industries and will help achieve the United States’ goal of zero emissions by 2030.”
Feng notes that the U.S. Department of Energy Hydrogen and Fuel Cell Technologies Office has established benchmarks of technologies that can produce clean hydrogen at $2 per kilogram by 2025 and $1 per kilogram by 2030 as part of the Hydrogen Energy Earth shot target of cutting the cost of clean hydrogen by 80%, from $5 to $1 per kilogram, in one decade.
Feng’s group is working on a water electrolysis method for clean hydrogen generation that employs electricity from renewable sources to split water and produce clean hydrogen.
However, he claims that the efficiency of water splitting is low, owing to a significant overpotential, or the gap between the real and theoretical potential of an electrochemical reaction in one of the process’s important half-reactions, the oxygen evolution reaction, or OER.
“Catalysts are critical to promoting the water-splitting reaction by lowering the overpotential, and thus lowering the total cost for hydrogen production,” Feng said. “Our first study in JACS Au laid the foundation for us, and as demonstrated in our Science Advances article we now can better manipulate atoms on the surface to design catalysts with the desired structure and composition.”
Feng’s research was funded by the National Science Foundation and the Department of Energy through the Northwest Nanotechnology Infrastructure site at Oregon State University.
Collaborating with Feng and Wang were researchers from Argonne National Laboratory, the University of Texas, Peking University, Pacific Northwest National Laboratory, Northwestern University, South China University of Technology, the University of Cambridge, the University of California, Berkeley, and Singapore’s Nanyang Technological University.
