Abstract: A method of fabricating a catalyst material comprises forming or receiving a precursor solution of an iridium precursor compound, adding a 3d orbital transition metal to the precursor solution, adding a surfactant compound to the precursor solution to provide a precursor and surfactant mixture, reacting the iridium precursor compound with a nitrate salt of an alkaline metal cation to provide a reaction product comprising an iridium nitrate, and calcining the iridium nitrate at a specified calcination temperature to convert the iridium nitrate to form catalyst particles comprising an iridium oxide.

Abstract: A fuel cell stack that includes a gas diffusion media for the end cells in the stack that has less of an intrusion into the flow field channels of the end cells that the other cells, so as to increase the flow rate through the flow channels in the end cells relative to the flow rate through the flow channels in the other cells. A different diffusion media can be used in the end cells than the nominal cells, where the end cell diffusion media has less of a channel intrusion as a result of diffusion media characteristics. Also, the same diffusion media could be used in the end cells as the nominal cells, but the end cell diffusion media layers could be thinner than the nominal cell diffusion media layers. Further, a higher amount of pre-compression can be used for the diffusion media in the end cells.

Abstract: A fuel cell stack that includes a gas diffusion media for the end cells in the stack that has less of an intrusion into the flow field channels of the end cells that the other cells, so as to increase the flow rate through the flow channels in the end cells relative to the flow rate through the flow channels in the other cells. A different diffusion media can be used in the end cells than the nominal cells, where the end cell diffusion media has less of a channel intrusion as a result of diffusion media characteristics. Also, the same diffusion media could be used in the end cells as the nominal cells, but the end cell diffusion media layers could be thinner than the nominal cell diffusion media layers. Further, a higher amount of pre-compression can be used for the diffusion media in the end cells.

Abstract: A fuel cell stack that includes a gas diffusion media for the end cells in the stack that has less of an intrusion into the flow field channels of the end cells that the other cells, so as to increase the flow rate through the flow channels in the end cells relative to the flow rate through the flow channels in the other cells. A different diffusion media can be used in the end cells than the nominal cells, where the end cell diffusion media has less of a channel intrusion as a result of diffusion media characteristics. Also, the same diffusion media could be used in the end cells as the nominal cells, but the end cell diffusion media layers could be thinner than the nominal cell diffusion media layers. Further, a higher amount of pre-compression can be used for the diffusion media in the end cells.

Abstract: A fuel cell stack that includes a gas diffusion media for the end cells in the stack that has less of an intrusion into the flow field channels of the end cells that the other cells, so as to increase the flow rate through the flow channels in the end cells relative to the flow rate through the flow channels in the other cells. A different diffusion media can be used in the end cells than the nominal cells, where the end cell diffusion media has less of a channel intrusion as a result of diffusion media characteristics. Also, the same diffusion media could be used in the end cells as the nominal cells, but the end cell diffusion media layers could be thinner than the nominal cell diffusion media layers. Further, a higher amount of pre-compression can be used for the diffusion media in the end cells.

Abstract: A method of operating a fuel cell is described. The method includes controlling the temperature of the anode plate and the temperature of the cathode plate to obtain a temperature difference of at least about 2° C. between the anode plate and the cathode plate. A fuel cell is also described.

Abstract: A gas diffusion media is described. The gas diffusion media comprises a conductive porous substrate; and a microporous layer; wherein a cathode effective transport length is in a range of about 700 to about 1900 ?m; wherein an overall thermal resistance is in a range of about 1.8 to about 3.8 cm2-K/W; and wherein a ratio of the cathode effective transport length to an anode effective transport length is greater than about 2.

Abstract: A gas diffusion media is described. The gas diffusion media comprises a conductive porous substrate; and a microporous layer; wherein a cathode effective transport length is in a range of about 700 to about 1900 ?m; wherein an overall thermal resistance is in a range of about 1.8 to about 3.8 cm2-K/W; and wherein a ratio of the cathode effective transport length to an anode effective transport length is greater than about 2.

Abstract: A fuel cell includes a first electrically conductive plate and a first gas diffusion layer. The first gas diffusion layer is disposed over the first electrically conductive plate. Characteristically, the first gas diffusion layer comprises a first fibrous sheet having fibers coated with an electrically conductive layer. A first catalyst layer is disposed over the first gas diffusion layer and an ion conducting membrane is disposed over the first catalyst layer. The fuel cell also includes a second catalyst layer disposed over the ion conducting membrane with a second gas diffusion layer disposed over the second catalyst layer. A second electrically conductive plate is disposed over the second gas diffusion layer. Methods for forming the gas diffusion layers and the fuel cell are also provided.

Abstract: A method of operating a fuel cell is described. The method includes controlling the temperature of the anode plate and the temperature of the cathode plate to obtain a temperature difference of at least about 2° C. between the anode plate and the cathode plate. A fuel cell is also described.

Abstract: A method for optimizing a fuel cell diffusion media having a spatially varying mass transport resistance is provided. The method includes at least two passes where a first-pass D/Deff profile for the fuel cell diffusion media is provided and applied to a computational model of the fuel cell having a baseline variable profile. At least one first-pass variable profile resulting from the application of the first-pass D/Deff profile to the computational mode is calculated and compared to a desired variable range. The first-pass D/Deff profile is refined, if necessary, to provide a second-pass D/Deff profile. A relative performance of the fuel cell with a second-pass variable profile resulting from an application of the second-pass D/Deff profile is determined. The second-pass D/Deff profile is refined, if necessary, until the second-pass variable profile has a desirable performance. An effective D/Deff profile is thereby provided.

Abstract: A method for optimizing a fuel cell diffusion media having a spatially varying mass transport resistance is provided. The method includes at least two passes where a first-pass D/Deff profile for the fuel cell diffusion media is provided and applied to a computational model of the fuel cell having a baseline variable profile. At least one first-pass variable profile resulting from the application of the first-pass D/Deff profile to the computational mode is calculated and compared to a desired variable range. The first-pass D/Deff profile is refined, if necessary, to provide a second-pass D/Deff profile. A relative performance of the fuel cell with a second-pass variable profile resulting from an application of the second-pass D/Deff profile is determined. The second-pass D/Deff profile is refined, if necessary, until the second-pass variable profile has a desirable performance. An effective D/Deff profile is thereby provided.

Abstract: A fuel cell stack that includes a gas diffusion media for the end cells in the stack that has less of an intrusion into the flow field channels of the end cells that the other cells, so as to increase the flow rate through the flow channels in the end cells relative to the flow rate through the flow channels in the other cells. A different diffusion media can be used in the end cells than the nominal cells, where the end cell diffusion media has less of a channel intrusion as a result of diffusion media characteristics. Also, the same diffusion media could be used in the end cells as the nominal cells, but the end cell diffusion media layers could be thinner than the nominal cell diffusion media layers. Further, a higher amount of pre-compression can be used for the diffusion media in the end cells.