| US 7,569,303 B2 | ||
| Membrane electrode assembly with modified catalyst layout | ||
| David Frank, Scarborough (Canada); Nathaniel Ian Joos, Toronto (Canada); Mario Dzamarija, Toronto (Canada); Raymond Candido, Toronto (Canada); and Rami Michel Abouatallah, Toronto (Canada) | ||
| Assigned to Hydrogenics Corporation, Mississauga, ON (Canada) | ||
| Filed on Sep. 24, 2004, as Appl. No. 10/948,327. | ||
| Prior Publication US 2006/0068267 A1, Mar. 30, 2006 | ||
| Int. Cl. H01M 4/00 (2006.01); H01M 2/00 (2006.01); H01M 2/08 (2006.01) | ||
| U.S. Cl. 429—40 [429/34; 429/35; 429/44] | 16 Claims |

| 1. 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.
|