University of Massachusetts Amherst researchers have designed a hydrogen fuel cell that could potentially make the technology more efficient and affordable by improving proton transfer between the anode and cathode.
For many hydrogen fuel cells, hydrogen goes in and water and electricity come out.
In between the electrodes, the hydrogen splits into protons and electrons. The electrons go through an electrical circuit while the protons travel through a synthetic membrane. When they meet on the other side, they come together in a chemical reaction that produces electricity and water.
Fuel cells work best under conditions that are low in humidity and high in temperature. The tricky part is that the membranes must channel the protons in the same dry environment. Few materials can do this efficiently.
But in a study published yesterday in Nature Chemistry, scientists at the Fueling the Future Center for Chemical Innovation describe a possible solution: a hybrid membrane comprised of both conducting and nonconducting nano-structures.
Conventionally, the membranes consist only of conducting materials, such as Nafion. According to the researchers, however, the more conducting the better is not the ideal composition. Bio-mimicry led the researchers to the idea.
Sankaran Thayumanavan, the center’s director, in a statement:
We took a cue from these naturally occurring proteins which can transport proton groups inside our bodies over distances of a few nanometers at extremely fast speeds without using water. We hypothesized that just as in these proteins, certain shapes or combinations of block copolymers that combine some conducting and some nonconducting nanostructures might conduct protons better than a uniform matrix.
Further he says, conductivity could be 1,000 times better through their nanostructure assembly, which they have been testing with different polymer combos. They hope the result will be a stable, durable membrane that transfers protons at optimum operating temperatures and viable for commercial use.
Image: NASA
