Electrochemical fuel cell assembly with integral selective oxidizer
AssigneeBallard Power Systems Inc.
InventorsDavid P. Wilkinson, Henry H. Voss, James Dudley, Gordon J. Lamont, Vesna Basura
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Abstract
A method and apparatus selectively oxidizes, within the fuel cell assembly, the carbon monoxide present in a fuel stream fed to the assembly. A quantity of catalyst is contained within at least a portion of a fuel stream passageway within the stack. The carbon monoxide is selectively oxidized by the catalyst to carbon dioxide, and carbon monoxide produced by the reverse water-shift reaction is also oxidized.
Claims18
An apparatus for selectively oxidizing carbon monoxide to carbon dioxide, said carbon monoxide present in a fuel stream introduced to an electrochemical fuel cell stack, the apparatus comprising:
- an electrochemical fuel cell stack, said stack comprising a plurality of fuel cells, said stack further comprising a fuel inlet and a fuel outlet, said fuel cells comprising a plurality of electrochemically active areas containing electrocatalyst and a plurality of non-electrochemically active areas;
- a passageway within said fuel stack, said passageway for directing a fuel stream within said stack between said fuel inlet and said fuel outlet, said fuel stream comprising carbon monoxide, carbon dioxide, and hydrogen;
- means for containing a quantity of catalyst within at least a portion of said passageway, said catalyst promoting oxidation of carbon monoxide to carbon dioxide in the presence of oxygen, said at least a portion of said passageway located within said plurality of non-electrochemically active areas.
An apparatus for the selective oxidation of carbon monoxide to carbon dioxide, said carbon monoxide being present in a fuel stream introduced to an electrochemical fuel cell, said apparatus comprising an electrochemical fuel cell comprising:
- (a) first and second separator layers, said first and second layers substantially impermeable to a fuel stream, said fuel stream comprising carbon monoxide, carbon dioxide, and hydrogen;
- and
- (b) a catalytic assembly disposed between said first and second layers, said catalytic assembly comprising at least one layer of porous sheet material having interstitial spaces said at least one layer of porous sheet material further comprising first and second major surfaces, said first major surface facing said first separator layer and said second major surface facing said second separator layer, said catalytic assembly further comprising a quantity of catalyst either disposed on said first major surface or said second major surface, or disposed within the interstitial spaces of said at least one porous layer, or any combination thereof, said catalyst promoting oxidation of carbon monoxide to carbon dioxide in the presence of oxygen;
- whereby directing said fuel stream between said first and second layers through said interstitial spaces causes said fuel stream to contact at least a portion of said catalyst.
Dependencies are inferred from the claim text.