Researchers have discovered a new hydrogen-generating catalyst capable of creating hydrogen from water in a sustainable manner. This could be the end of sea drilling and digging coal mines and other unsustainable ways of producing fuel.
The researchers from the University of Illinois at Urbana-Champaign have made fuel from water. The report published in Angewandte Chemie journal reported an electrocatalytic material made from mixing water compounds with the perchloric acid.
Credit: Photo by L. Brian Stauffer
Electrolyzers use electricity to break water molecules into oxygen and hydrogen. The most efficient of these devices use corrosive acids and electrode materials made of the metal compounds iridium oxide or ruthenium oxide. Iridium oxide is the more stable of the two, but iridium is one of the least abundant elements on Earth, so researchers are in search of an alternative material.
“Much of the previous work was performed with electrolyzers made from just two elements — one metal and oxygen,” said Hong Yang, a co-author, and professor of chemical and biomolecular engineering at Illinois. “In a recent study, we found if a compound has two metal elements — yttrium and ruthenium — and oxygen, the rate of water-splitting reaction increased.”
They first experimented with the procedure of making the new material by using different acids and heating temperatures to increase the rate of water-splitting reaction. They discovered that on using perchloric acid as a catalyst under heat, the physical nature of the yttrium ruthenate product changed.
“The material became more porous and also had a new crystalline structure, different from all the solid catalysts we made before,” said Jaemin Kim, the lead author, and a postdoctoral researcher.
So, they developed a new porous material- a pyrochlore oxide of yttrium ruthenate that can split water molecules at a significantly higher rate.
Because of the increased activity it promotes, a porous structure is highly desirable when it comes electrocatalysts,” Yang said. “These pores can be produced synthetically with nanometer-sized templates and substances for making ceramics; however, those can’t hold up under the high-temperature conditions needed for making high-quality solid catalysts.”
The new material when looked under electron microscope appears four times more porous than the original yttrium ruthenate and three times more porous than iridium ruthenate and ruthenium oxides used commercially.
“It was surprising to find that the acid we chose as a catalyst for this reaction turned out to improve the structure of the material used for the electrodes,” Yang said. “This realization was fortuitous and quite valuable for us.”
The next steps for the group are to fabricate a laboratory-scale device for further testing and to continue to improve the porous electrode stability in acidic environments.
“Stability of the electrodes in acid will always be a problem, but we feel that we have come up with something new and different when compared with other work in this area,” Yang said. “This type of research will be quite impactful regarding hydrogen generation for sustainable energy in the future.”