Catalytic coating of structured heat exchanger plates

Abstract

A process for producing a coated, structured heat exchanger plate for a reactor in a fuel cell system comprises application of a catalytic component in at least one layer by means of pad printing, exclusively in the recesses and/or the flanks of the heat exchanger plate.

What is claimed is:  
     
         1 . A process for producing a coated, structured heat exchanger plate for a reactor in a fuel cell system, comprising: applying a catalytic component continuously or discontinuously in at least one layer, by means of pad printing, exclusively to at least one of recesses and flanks of the heat exchanger plate.  
     
     
         2 . The process according to  claim 1 , wherein: 
 said catalytic component is applied in at least two stages; and    each stage is in a different zone of the heat exchanger plate.    
     
     
         3 . The process according to  claim 1 , wherein said catalytic component contains at least one of a catalytically active material component and a hydrophobic material component.  
     
     
         4 . The process according to  claim 3 , wherein said catalytically active material component is in supported form.  
     
     
         5 . The process according to  claim 3 , wherein said catalytically active material component contains at least one of a ceramic binder and a polymeric binder.  
     
     
         6 . The process according to  claim 3 , wherein at least one of composition and concentration of said catalytically active material component is varied over the length of the heat exchanger plate.  
     
     
         7 . The process according to  claim 1 , wherein: 
 the process is carried out at room temperature; and    the printing medium and coating material are not heated.    
     
     
         8 . The process according to  claim 7 , further comprising a drying step at a temperature between 100° C. to 200° C., inclusive, subsequent to said applying by means of pad printing.  
     
     
         9 . The process according to  claim 7 , wherein the heat exchanger plate is heated while the catalytic component is being applied.  
     
     
         10 . The process according to  claim 8 , further comprising a final step of calcining at a temperature of approximately 500° C.  
     
     
         11 . A process for producing a coated, structured heat exchanger plate for a fuel cell reactor, comprising: 
 applying at least one layer of a catalytic component to at least one region of the heat exchanger plate with a printing medium,    wherein said catalytic component is applied exclusively to at least one location selected from the group consisting of: the heat exchanger plate recesses and the heat exchanger plate flanks    
     
     
         12 . The process according to  claim 11 , wherein said at least one layer comprises at least two different catalysts.  
     
     
         13 . The process according to  claim 11 , wherein said at least one layer comprises a thickness of 5 to 50 μm.  
     
     
         14 . The process according to  claim 11 , wherein a gradient is created by applying said catalytic component in at least two different thicknesses.  
     
     
         15 . The process according to  claim 11 , wherein said catalytic component is a catalytically active material.  
     
     
         16 . The process according to  claim 15 , wherein said catalytically active material further comprises a thermal stabilizing agent.  
     
     
         17 . The process according to  claim 11 , wherein said catalytic component is a hydrophobic material.  
     
     
         18 . The process according to  claim 11 , wherein said catalytic component is a combination of a catalytically active material and a hydrophobic material.  
     
     
         19 . A device for coating a heat exchanger plate for a fuel cell reactor, said heat exchanger having a three dimensional structured contour including a plurality of recesses and flanks, said device comprising: 
 a printing pad,    wherein said printing pad is made of a smooth elastic material which is deformable to match the three dimensional contour of the heat exchanger plate by being pressed thereon;    whereby a catalytic component applied on said printing pad is deposited in the form of at least one layer on at least one of the flanks and recesses of said three dimensional contour.