Ion conducting polymer membranes

Abstract

Modified ion-conducting membranes ( 10 ), and a method for making the same, which increases the membrane ( 10 ) surface area, and, optionally, incorporates mono- and multi-metal ion-containing catalysts for both fuel consumption catalysis in fuel cells as well as catalysis of reactions to ameliorate the effects of CO and other impurities in fuel cells. The membranes ( 10 ) modified by these methods can find application in catalysis and transport applications.

1 . An ion conducting polymer membrane ( 10 ) that can be be placed between an associated anode and an associated cathode, the ion conducting polymer membrane exhibiting surface deformation such that at least one deformed surface area of said membrane exceeds a subtended area of an unmodified membrane surface by at least 20% and further comprising a catalyst layer ( 20 ) deposited on, inside, or on and inside the surface of said membrane. 
     
     
         2 . An ion conducting polymer membrane ( 10 ) according to  claim 1 , wherein said deformed surface area exceeds said subtended area by at least 50%. 
     
     
         3 . An ion conducting polymer membrane ( 10 ) according to  claim 1 , wherein said deformed surface area exceeds said subtended area by at least 70%. 
     
     
         4 . An ion conducting polymer membrane ( 10 ) according to  claim 1 , wherein said deformed surface area exceeds said subtended area by at least 100%. 
     
     
         5 . An ion conducting polymer membrane ( 10 ) according to  claim 1 , wherein said membrane ( 10 ) comprises a perfluorinated ionomer. 
     
     
         6 . An ion conducting polymer membrane ( 10 ) according to  claim 5 , wherein said membrane comprises a polymer containing a poly(tetrafluoroethylene) backbone chain and spaced perfluorinated polyether side chains, each of said side chains terminated by a strongly hydrophilic acid group. 
     
     
         7 . An ion conducting polymer membrane ( 10 ) according to  claim 6 , wherein said acid group is a sulfonic acid group. 
     
     
         8 . An ion conducting polymer membrane ( 10 ) according to  claim 1 , wherein said surface comprises a plurality of protrusions wherein the distance between said protrusions is from about 0.1 to about 10 microns. 
     
     
         9 . An ion conducting polymer membrane ( 10 ) according to  claim 1 , wherein the catalyst layer ( 20 ) is deposited on or inside said surface of said membrane. 
     
     
         10 . An ion conducting polymer membrane ( 10 ) according to  claim 1 , wherein said catalyst layer ( 20 ) comprises Pt, Ru, Cu, Ni, Co, Rh, or Ag. 
     
     
         11 . A fuel cell employing an oxygen-containing compound as an oxidant and comprising the ion conducting membrane of  claim 1 . 
     
     
         12 . An ion conducting polymer membrane ( 10 ) according to  claim 1 , wherein said catalyst layer ( 20 ) comprises a transition metal.