Patent ID: 7569303

Claim:
An electrochemical cell assembly comprising: a) first and second flow field plates each including an active surface facing one another, and each having first and second sets of apertures for reactant fluid flow and optionally coolant flow, each set of apertures including an inlet aperture and an outlet aperture, the plates further including a feed structure for enabling reactant fluid flow from one of the inlet apertures along the active surface to one of the outlet apertures; b) first and second gas diffusion media disposed between the first and second flow field plates; and, c) a membrane electrode assembly, disposed between the first and second gas diffusion media, including: i) a proton exchange membrane; and, ii) a catalyst layer on each surface of the proton exchange membrane having a catalyst layout being generally disposed in between the first and second sets of apertures, wherein, for at least one surface of the membrane electrode assembly, the catalyst layout is configured to omit the catalyst from a portion of the proton exchange membrane adjacent an edge region of one of the first and second gas diffusion media, thereby enabling at least a portion of the reactant fluid flow to first encounter a region of the membrane electrode assembly without the catalyst, wherein the spacings between both of the inlet and outlet apertures that are involved with the reactant fluid flow that is provided to the catalyst layer and at least one portion of edges of the catalyst layout that are adjacent and nearest to the inlet and outlet apertures that are involved with reactant fluid flow are such that the catalyst layout omits the catalyst from a portion of the proton exchange membrane adjacent an edge region of one of the first and second gas diffusion media, thereby enabling at least a portion of the reactant fluid flow to first encounter a region of the membrane electrode assembly without the catalyst.