Washington, August 21 : Scientists have found a way to convert ethanol and other biofuels into hydrogen very efficiently, by using a new catalyst that makes hydrogen from ethanol with 90 percent yield, at a workable temperature, and using inexpensive ingredients.
According to Umit Ozkan, professor of chemical and biomolecular engineering at Ohio State University in the US, the new catalyst is much less expensive than others being developed around the world, because it does not contain precious metals, such as platinum or rhodium.
"Rhodium is used most often for this kind of catalyst, and it costs around 9,000 dollars an ounce," said Ozkan. "Our catalyst costs around 9 dollars a kilogram," she added.
The Ohio State catalyst could help make the use of hydrogen-powered cars more practical in the future, said Ozkan.
"There are many practical issues that need to be resolved before we can use hydrogen as fuel -- how to make it, how to transport it, how to create the infrastructure for people to fill their cars with it," she explained.
"Our research lends itself to what's called a 'distributed production' strategy. Instead of making hydrogen from biofuel at a centralized facility and transporting it to gas stations, we could use our catalyst inside reactors that are actually located at the gas stations," said Ozkan.
"So we wouldn't have to transport or store the hydrogen - we could store the biofuel, and make hydrogen on the spot," she added.
The catalyst is inexpensive to make and to use compared to others under investigation worldwide. Those others are often made from precious metals, or only work at very high temperatures.
Precious metals have high catalytic activity and - in most cases - high stability, but they're also very expensive.
"So our goal from the outset was to come up with a precious-metal-free catalyst, one that was based on metals that are readily available and inexpensive, but still highly active and stable. So that sets us apart from most of the other groups in the world," said Ozkan.
The new dark gray powder is made from tiny granules of cerium oxide - a common ingredient in ceramics - and calcium, covered with even smaller particles of cobalt.
It produces hydrogen with 90 percent efficiency at 660 degrees Fahrenheit (around 350 degrees Celsius) - a low temperature by industrial standards.
According to Ozkan, whenever a process works at a lower temperature, that brings energy savings and cost savings.
"Also, if the catalyst is highly active and can achieve high hydrogen yields, we don't need as much of it. That will bring down the size of the reactor, and its cost," he said.