Washington, Nov 25 (IANS) Researchers have found a novel way to make fuel cells more energy efficient and increase their power output by fine-tuning metal catalysts at the atomic scale.
A nano size squeeze can significantly boost the performance of platinum catalysts that help generate energy in fuel cells, according to the new study by scientists at Stanford University.
"Our tuning technique could make fuel cells more energy efficient and increase their power output," said study co-author Yi Cui, Professor at Stanford and SLAC National Accelerator Laboratory in California.
"It could also improve the hydrogen-generation efficiency of water splitters and enhance the production of other fuels and chemicals," Cui noted.
The team bonded a platinum catalyst to a thin material that expands and contracts as electrons move in and out, and found that squeezing the platinum a fraction of a nanometre nearly doubled its catalytic activity.
"In this study, we present a new way to fine-tune metal catalysts at the atomic scale," said lead author Haotian Wang, a former graduate student at Stanford now at Harvard University.
"We found that ordinary battery materials can be used to control the activity of platinum and possibly for many other metal catalysts," Wang noted.
The new technique described in the journal Science can be applied to a wide range of clean technologies, including fuel cells that use platinum catalysts to generate energy, and platinum electrolysers that split water into oxygen and hydrogen fuel, Wang said.
Catalysts are used to make chemical reactions go faster while consuming less energy. The performance of a metal catalyst depends on its electronic structure -- that is, how the electrons orbiting individual atoms are arranged.
The team introduced a novel way to compress or separate the atoms by 5 percent, a mere 0.01 nanometer.
"That might not seem like much, but it's really a lot," Cui said.
"We found that compression makes platinum much more active," Wang added.
"We observed a 90 per cent enhancement in the ability of platinum to reduce oxygen in water. This could improve the efficiency of hydrogen fuel cells," Wang said.
