Membrane electrode assembly with improved cohesion

Abstract

A membrane electrode assembly comprises an anode electrode comprising an anode catalyst layer; a cathode electrode comprising a cathode catalyst layer; and a polymer electrolyte membrane interposed between the anode electrode and the cathode electrode; wherein at least one of the anode and cathode catalyst layers comprises a block co-polymer comprising poly(ethylene oxide) and poly(propylene oxide).

1 .- 10 . (canceled) 
     
     
         11 . A method of making a catalyst-coated membrane comprising the steps of:
 a) dissolving a non-proton-conducting block co-polymer comprising poly(ethylene glycol) and poly(propylene glycol) in an aqueous solution to form a block co-polymer solution;   b) mixing the block co-polymer solution with an ionomer and a catalyst to form a catalyst ink;   c) coating the catalyst ink on one side of an ion-exchange membrane to form a coated ion-exchange membrane; and   d) drying the coated ion-exchange membrane to form the catalyst-coated membrane.   
     
     
         12 . The method of  claim 11 , wherein the block co-polymer comprises poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide). 
     
     
         13 . The method of  claim 11 , wherein the block co-polymer comprises poly(propylene oxide)-poly(ethylene oxide)-poly(propylene oxide). 
     
     
         14 . The method of  claim 11 , wherein the catalyst is selected from the group consisting of platinum, gold, ruthenium, iridium, cobalt, nickel, molybdenum, palladium, iron, tin, titanium, manganese, cerium, chromium, copper, and tungsten, and alloys, solid solutions, and intermetallic compounds thereof. 
     
     
         15 . The method of  claim 11 , wherein the catalyst comprises a non-precious metal. 
     
     
         16 . The method of  claim 11 , wherein drying the coated ion-exchange membrane comprises heating the coated ion-exchange membrane at an elevated temperature above room temperature. 
     
     
         17 . The method of  claim 11 , further comprising compacting the coated ion-exchange membrane. 
     
     
         18 . An electrode comprising a catalyst layer, the catalyst layer comprising a catalyst and a binder comprising an ionomer and a block co-polymer comprising poly(ethylene oxide) and poly(propylene oxide). 
     
     
         19 . The electrode of  claim 18 , wherein the electrode is an anode. 
     
     
         20 . The electrode of  claim 18 , wherein the electrode is a cathode.