Electrochemical catalytic reduction cell for the reduction of NO.sub.x in an O.sub.2 -containing exhaust emission
AssigneeCeramatec, Inc.
InventorsMeilin Liu, Jiemin Zhu, Ashok V. Joshin
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Abstract
Disclosed are a process and apparatus for removing NO.sub.x in an O.sub.2 -containing exhaust emission based on electrochemically catalytic reduction processes. Advantages to the electrochemically catalytic reduction process include high NO.sub.x conversion efficiency and suitability for the removal of NO.sub.x from the O.sub.2 -containing exhaust of mobile combustion sources due to the simplicity in construction, maintenance and operation (chemical-reducing agents are not required in the process).
Claims13
An electrochemical cell for reduction of NOx comprising:
- (a) a solid electrolyte having sides;
- (b) an anode on one side of the solid electrolyte;
- (c) two layers on the side of the solid electrolyte opposite that of the anode, one of said layers is a porous oxide catalyst, and the other layer is an electron conducting layer, said electron conducting layer made from a material selected from the group consisting of lanthanum strontium manganate, lanthanum strontium manganese cobalt oxide, lanthanum strontium cobalt oxide, lanthanum strontium cobalt ferride, platinum and mixtures thereof;
- and
- (d) a circuit that applies a potential across said anode and either said porous oxide catalyst or said electron conducting layer.
An electrochemical cell for nitrogen oxide reduction comprising:
- a solid electrolyte having sides;
- a metallic anode positioned on one side of said solid electrolyte;
- a cathode positioned on the side of the solid electrolyte opposite that of the metallic anode, said cathode comprising a porous gas-diffusion catalyst;
- and
- a conductive layer, comprising a perovskite oxide, positioned on the cathode to enhance the conductivity of the electrochemical cell and maintain the selective absorption of nitrogen oxide.
A device for the electrochemical reduction of NO.sub.x comprising:
- (a) a container;
- (b) an electrochemical cell, contained within said container, said electrochemical cell comprising:
- (i) a solid electrolyte having sides,
- (ii) a metallic anode positioned on one side of said solid electrolyte,
- (iii) a cathode positioned on the side of the solid electrolyte opposite that of the metallic anode, said cathode comprising a porous gas-diffusion catalyst, and
- (iv) a conductive layer positioned on the catalyst to enhance the conductivity of the electrochemical cell and maintain the selective absorption of nitrogen oxide;
- (c) a gas inlet leading into said container, said gas inlet directed to the electrochemical cell;
- (d) a porous metal grid surrounding said electrochemical cell;
- (e) a power source for electrifying said porous metal grid and said cathode;
- and
- (f) a gas outlet for removing gas from said container.
An electrochemical cell for reduction of NOx comprising:
- (a) a solid electrolyte having sides;
- (b) an anode on one side of the solid electrolyte;
- (c) two layers on the side of the solid electrolyte opposite that of the anode, one of said layers is a porous oxide catalyst, said porous oxide catalyst made from a material selected from the group consisting of (V.sub.2 O.sub.5).sub.x (TiO.sub.2).sub.1-x, (V.sub.2 O.sub.5).sub.x (SiO.sub.2).sub.1-x, (V.sub.2 O.sub.5).sub.x (.gamma.-Al.sub.2 O.sub.3).sub.1-x, CuO.sub.2, SnO.sub.2, NiO, Fe.sub.3 O.sub.4, Nb.sub.2 O.sub.5, lanthanum copper ferride, lanthanum strontium manganese copper ferride, Cu.sub.x Mo.sub.6 S.sub.8, and mixtures thereof, wherein x is 0.01 to 0.99, and the other layer is an electron conducting layer;
- and
- (d) a circuit that applies a potential across said anode and either said porous oxide catalyst or said electron conducting layer.
Dependencies are inferred from the claim text.