A REDOX FUEL-CELL THAT OPERATES WITH METHANE AS FUEL AT 120-DEGREES-C

Platinum black efficiently catalyzes the oxidation of methane by iron( III) to generate carbon dioxide and eight equivalents of iron(II) in s olutions of sulfuric acid in water. The rate of oxidation increases ov er 4 hours to reach similar to 4.83 X 10(-2) moles of iron(II) per gra m atom of surface platinum per second. A redox fuel cell was assembled that used this reaction in a liquid reformer to generate soluble redu cing equivalents of iron(II) from methane, which was electrochemically oxidized to iron(III) in the cell. A vanadium(V)-(IV)-nitric acid-O-2 redox system catalyzed the electrochemical reduction of O-2. The open -circuit voltage of the cell was 0.48 volt, and the maximum power outp ut of the cell was 8.1 milliwatts per cubic centimeter of graphite fel t electrode.