Composite membranes for direct methanol fuel cells

We have made polyvinylalcohol membranes containing mordenite which have twe nty times better selectivity for protons over methanol than perfluorinated sulfonic acid polymers. Membranes like these should improve the efficiencie s of fuel cells fed directly with methanol. Our results show that further i mprovements are possible with composite membranes, but that these improveme nts will require polymers less conductive than those currently used. This i s the opposite of conventional wisdom. (C) 2001 The Electrochemical Society .