Novel catalyst can now help harvest fuel from water

Scientists have developed an inexpensive material that can help split water to produce hydrogen fuel. Most systems to split water into its components - hydrogen and oxygen - require two catalysts, one to spur a reaction to separate the hydrogen and a second to produce oxygen.

The new catalyst, made of iron and dinickel phosphides on commercially available nickel foam, performs both functions. Researchers from the University of Houston (UH) and the California Institute of Technology in the US said it has the potential to dramatically lower the amount of energy required to produce hydrogen from water while generating a high current density, a measure of hydrogen production.

Lower energy requirements means the hydrogen could be produced at a lower cost. "It puts us closer to commercialisation," said Zhifeng Ren, professor at UH. Hydrogen is considered a desirable source of clean energy, in the form of fuel cells to power electric motors or burned in internal combustion engines, along with a number of industrial uses.

Since it can be compressed or converted to liquid, it is more easily stored than some other forms of energy, said Ren, lead author of study published in the journal Nature Communications. However, finding a practical, inexpensive and environmentally friendly way to produce large amounts of hydrogen gas - especially by splitting water into its component parts - has been a challenge. Most hydrogen is currently produced through steam methane reforming and coal gasification; those methods raise the fuel's carbon footprint despite the fact that it burns cleanly.

While traditional catalysts can produce hydrogen from water, Shuo Chen, assistant professor at UH, said they generally rely on expensive platinum group elements. That raises the cost, making large-scale water splitting impractical. "In contrast, our materials are based on earth abundant elements and exhibit comparable performance with those of platinum group materials," she said. 

"It can be potentially scaled-up at low cost, which makes it very attractive and promising for the commercialization of water splitting," she added. Researchers said the catalyst remained stable and effective through more than 40 hours of testing.