Fuel cell limiting co poisoning and poisoning diagnostic process

Abstract

A unit cell of a fuel cell may include: a membrane-electrode assembly including a proton exchange membrane, an anode electrode fastened to a first face of the proton exchange membrane, a first flow guide plate positioned facing the anode electrode and including at least one flow channel having a fuel inlet zone, a median flow zone and a fuel outlet zone. The anode electrode may have, at the fuel outlet zone, a tolerance to carbon monoxide pollution greater than its average tolerance to carbon monoxide pollution at the median flow zone and at the fuel inlet zone.

1 . A cell configured for a fuel cell, comprising:
 membrane-electrode assembly, comprising a proton exchange membrane, an anode electrode fixed to a first face of the proton exchange membrane, and a first flow guide plate arranged opposite the anode electrode, the first flow guide comprising a flow channel having a fuel inlet zone, a middle flow zone, and a fuel outlet zone;   wherein, at the fuel outlet zone, the anode electrode has a carbon monoxide pollution tolerance greater than its average carbon monoxide pollution tolerance at the middle flow zone and at the fuel inlet zone.   
     
     
         2 . The cell of  claim 1 , wherein the membrane-electrode assembly further comprises a cathode electrode fixed to a second face of the proton exchange membrane, and
 wherein the cell further comprises a second flow guide plate arranged opposite the cathode electrode comprising a flow channel.   
     
     
         3 . The cell of  claim 2 , wherein the cathode electrode comprises a zone having a catalyst loading greater than its average catalyst loading outside this zone. 
     
     
         4 . The cell of  claim 3 , wherein the flow channel comprises an oxidizer inlet zone, a middle flow zone, and an oxidizer outlet zone,
 wherein the zone of the cathode electrode having a greater catalyst loading is positioned at the oxidizer outlet zone.   
     
     
         5 . The cell of  claim 3 , wherein the oxidizer outlet zone of the cathode electrode is positioned vertically to the fuel inlet zone. 
     
     
         6 . The cell of  claim 3 , wherein the oxidizer inlet zone of the cathode electrode is positioned vertically to the fuel outlet zone, and
 wherein the oxidizer inlet zone of the cathode electrode has a catalyst loading lower than its average catalyst loading outside this zone.   
     
     
         7 . The cell of  claim 2 , wherein the flow channel comprises oxidizer inlet zone, a middle flow zone, and an oxidizer outlet zone, and
 wherein the cathode electrode comprises a PtX alloy catalyst, X being a metal and a proportion of the metal X in the oxidizer outlet zone being lower than an average proportion of the metal X of the cathode catalyst outside the oxidizer outlet zone.   
     
     
         8 . The cell of  claim 7 , wherein the proportion of the metal X in the oxidizer outlet zone is at least two times lower than the average proportion of the metal X of the cathode catalyst outside the oxidizer outlet zone. 
     
     
         9 . The cell of  claim 7 , wherein the metal X is cobalt. 
     
     
         10 . The cell of  claim 1 , wherein the anode electrode has, at the fuel outlet zone, a carbon monoxide tolerance at least 30% greater than its average carbon monoxide tolerance at the middle flow zone and at the fuel inlet zone. 
     
     
         11 . The cell of  claim 1 , wherein the anode electrode comprises PtRu at its outlet zone. 
     
     
         12 . The cell of  claim 1 , wherein the anode electrode has, at its outlet zone, a catalyst loading greater than its average loading outside the outlet zone. 
     
     
         13 . The cell of  claim 12 , wherein the anode electrode has, at its outlet zone, a catalyst loading at least 30% greater than its average loading outside the outlet. 
     
     
         14 . A membrane-electrode assembly configured for implementing the fuel cell of  claim 1 , the assembly comprising:
 a proton exchange membrane;   an anode electrode fixed to a first face of the proton exchange membrane, the anode electrode having, at a zone intended to be arranged at a fuel outlet, a carbon monoxide pollution tolerance greater than its average carbon monoxide pollution tolerance at a zone configured to be arranged at a middle flow zone and at a zone intended to be arranged at a fuel inlet.   
     
     
         15 . A method for simulating aging of a membrane/electrode assembly of the cell of  claim 1 , comprising:
 applying to a two-dimensional model of the fuel cell, a first dimension corresponding to a flow direction of a reagent, a second dimension corresponding to a thickness of the cell, cathode flow being modeled by a single flow channel, anode flow being modeled by a single flow channel, the two-dimensional model being configured to determine anode poisoning based on an amount of carbon monoxide in fuel, a flow of fuel comprising carbon monoxide, so as to determine poisoning of the anode by carbon monoxide based on a position in the first dimension.