US Patent 7229944 - Carbon fiber sheet

http://www.freepatentsonline.com/7229944.html

Catalytic membranes are a component of fuel cells that can help speed up reactions and improve efficiency. This patent from M.I.T. discloses catalytic membranes formed using carbon nanofibers. Claim 1 reads:

1. A structure comprising: a carbon fiber sheet-like structure having a thickness of less than 10 microns and including at least one carbon fiber having a length of greater than about 500 microns; and a catalytic material supported on the carbon fiber sheet-like structure, wherein carbon fiber of the structure has an average diameter of less than about 500 nanometers.