Research news: Hydrogen Fuel-cell Membrane Structure Conundrum Solved

The News:
Hydrogen Fuel-cell Membrane Structure Conundrum Solved
ScienceDaily (Dec. 16, 2007) — Fuel-cell cars are reaching commercial viability in today’s increasingly eco-conscious society, but despite their promise, even scientists have struggled to explain just how the fuel-cell’s central component – the proton exchange membrane – really works.

However, a team of researchers at the U.S. Department of Energy’s Ames Laboratory has offered a new model that provides the best explanation to date for the membrane’s structure and how it functions. And armed with that information, scientists should be able to build similar fuel-cell membrane materials that are less expensive or have different properties, such as higher operating temperatures.
A fuel cell works by pumping hydrogen gas through the proton exchange membrane. In the process, the hydrogen gives up electrons in the form of electricity, then combines with oxygen gas to form water as the by-product. It can also work in reverse – when current is applied, water is split into its component gases, hydrogen and oxygen.
The model proposed by Ames Laboratory scientists Klaus Schmidt-Rohr and Qiang Chen, and detailed in the December issue of the journal Nature Materials, looked specifically at Nafion®, a widely used perfluorinated polymer film that stands out for its high selective permeability to water and protons. Schmidt-Rohr, who is also a professor of chemistry at Iowa State University, suggests that Nafion® has a closely packed network of nanoscale cylindrical water channels running in parallel through the material.

The Research:
Read the research behind this story in the journal Nature Materials.