Shelley Minteer, Professor, University of Utah.
UTAH, US: University of Utah engineers developed the first room-temperature fuel cell that uses enzymes to help jet fuel produce electricity without needing to ignite the fuel. These new fuel cells can be used to power portable electronics, off-grid power and sensors. A study of the new cells appears online in the American Chemical Society journal ACS Catalysis.
Fuel cells convert energy into electricity through a chemical reaction between a fuel and an oxygen-rich source such as air. If a continuous flow of fuel is provided, a fuel cell can generate electricity cleanly and cheaply. While batteries are used commonly to power electric cars and generators, fuel cells also now serve as power generators in some buildings, or to power fuel-cell vehicles such as prototype hydrogen-powered cars.
“The major advance in this research is the ability to use Jet Propellant-8 directly in a fuel cell without having to remove sulfur impurities or operate at very high temperature. This work shows that JP-8 and probably others can be used as fuels for low-temperature fuel cells with the right catalysts,” said Shelley Minteer, Professor, University of Utah.
Converting this jet fuel into electricity is difficult using standard techniques because jet fuel contains sulfur, which can impair metal catalysts used to oxidize fuel in traditional fuel cells. The conversion process is also inefficient, with only 30 per cent of the fuel converted to electricity under the best conditions.
To overcome these constraints, the Utah researchers used JP-8 in an enzymatic fuel cell, which uses JP-8 for fuel and enzymes as catalysts. Enzymes are proteins that can act as catalysts by speeding up chemical reactions. These fuel cells can operate at room temperature and can tolerate sulfur.
An enzyme “cascade” of two enzymes – alkane monooxygenase and alcohol oxidase – was used to catalyze JP-8. Hexane and octane, which are chemically similar to JP-8, also were tested as fuels. The researchers found that adding sulfur to their enzymatic fuel cell did not reduce power production.
“Enzymatic fuel cells are a newer type of fuel cell, so they are not currently on the market. However, researchers haven’t been able to use JP-8 before, because they haven’t had the enzymes to be able to oxidize JP-8,” said Minteer.
Solid-oxide fuel cells at temperatures above 950 degrees Fahrenheit have made use of JP-8, but this is the first demonstration at room temperature, said Minteer. Now that the team has shown the enzyme catalysts work, they will focus on designing the fuel cell and improving its efficiency, she added.
Minteer conducted the study with University of Utah postdoctoral researchers Michelle Rasmussen and Mary Arugula, and with Yevgenia Ulyanova, Erica Pinchon, Ulf Lindstrom and Sameer Singhal of CFD Research Corp in Huntsville, Alabama.
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