| 摘要 |
1,177,265. Fuel cell operation. ATLANTIC RICHFIELD CO. 31 March, 1967 [25 May, 1966], No. 14996/67. Heading H1B. The hydrogen permeable metallic membrane of a fuel cell anode is protected from corrosion by the electrolyte by applying a D.C. potential across the cell during periods of lowered hydrogen supply to mantain the membrane negative to the cathode. The potential difference may be 0.5 volts or more, but where the electrolyte is an alkali metal hydroxide it should not exceed the potential at which the metal deposits. During application of the potential, H 2 should be excluded from the membrane, for example by flushing it with an inert gas. If the hydrogen is formed in the fuel chamber by interaction of steam with a hydrocarbon, the hydrocarbon flow may be stopped so that the steam flow expels hydrogen from the membrane. In a particular embodiment fuel cell 10 is divided into 3 compartments by anode 11 and cathode 12 held in position by spacers 13, 14 and 15. The anode comprises porous carbon layer 11 and non-porous, H 2 permeable layer 27 of Ni, Pd or Pd alloy less than 0À0001 inch thick. In normal operation hydrocarbon and steam are supplied to chamber 16, oxidant is supplied to chamber 18 and fused NaOH is present in chamber 17. Water vapour escapes at vent 17a and current is supplied to the external load via switch 24. When the cell is switched off, valve 25 may be simultaneously closed, automatically closing switches 28 and 29 so that cell 30 supplies current to the fuel cell via rheostat 32 and the steam flow expels any hydrogen in the membrane 27, assisted or replaced by inert gas from valve 31.
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