Metallic blocking layers integrally associated with fuel cell electrode
structures and fuel cell electrode stack assemblies, as well as to methods
relating thereto, are disclosed herein. More specifically, the present
invention is directed to a metallic blocking layer integrally associated
with an electrode structure of a fuel cell system such as, for example, a
direct methanol fuel cell system. In this embodiment, the invention may be
characterized in that the electrode structure comprises an inorganic
(i.e., noncarbonaceous) support substrate having one or more discrete
porous regions, wherein the one or more discrete porous regions is defined
by an array of acicular pores disposed across the top surface area of the
electrode structure such that at least a portion of the blocking layer
covers the top surface area and protrudes into the array of acicular
pores. The blocking layer is preferably a substantially voidless metallic
membrane that is substantially impermeable to at least methanol and is
substantially permeable to hydrogen atoms.
