Studies of mixed oxides were made in order to determine if such materials could act as oxygen-reducing electrocatalysts in an acid fuel cell. Included were strontium and barium cobaltates and manganates with and without added titanium; lanthanum titanates, with and without calcium or strontium; calcium, strontium, and barium ruthenates; and mixed oxides of the systems Ti-Ta-O, V-Nb-O, Ce-Ta-O, Pr-Ta-O, Ce-Nb-O, and Ce-Pr-Ta-O. Choices were based upon producing variable valence and upon conferring stability at elevated temperatures (< 150C) in phosphoric acid. Barium ruthenate and the systems Ti-Ta-O, V-Nb-O, V-Ta-O, Ce-Ta-O were hot-acid stable. Potentiodynamic and galvanostatic studies are reported on materials from the Ti-Ta-O system, TiO2 as grown, TiO2 reduced with hydrogen, TiO2 with 0.1% Nb, lanthanum titanates with and without calcium or strontium, a tungsten bronze, barium ruthenate, and strontium titanate with .03% and with .15% Nb.

"Office of Research and Development." "Office of Energy, Minerals, and Industry." "National Bureau of Standards, Department of Commerce, Washington, DC. EPA Interagency agreement D4-0528, ROAP 21BKR-007, program element 1AB013." "EPA project officer: Stanley J. Bunas." "EPA-600/2-76-007." "PB248744"--Cover "January 1976." Includes bibliographical references. For sale by the National Technical Information Service, (Price upon application). 4to.