Abstract: Processes for forming films comprising multiple layers of nanostructured support elements are described. A first layer of nanostructured support elements is formed by depositing a base material on a substrate and annealing. Further growth of the first layer of nanostructures is then inhibited. Additional layers of nanostructured support elements may be grown on the first layer of nanostructures through additional deposition and annealing steps. The multilayer films provide increased surface area and are particularly useful in devices where catalyst activity is related to the surface area available to support catalyst particles.

Abstract: Components that include catalyst layers used in membrane electrode assemblies (MEAs), and methods of making such components are described. The catalyst layers yield more uniform current distributions across the active area of the MEA during operation. The catalyst layers may have a uniform catalyst activity profile of a less active catalyst to achieve more uniform current density over the MEA active area. The catalyst layers may have a variable activity profile, such as an activity profile with a varying slope, to compensate for the inherent nonlinearities of catalyst utilization during operation of an electrochemical fuel cell. Desired variable catalyst activity profiles may be achieved, for example, by varying the catalyst loading across the MEA from inlet to outlet ports or by varying the surface area of the catalyst loading or by varying the surface area of the catalyst support elements.

Abstract: A fuel cell cathode catalyst is provided comprising nanostructured elements comprising microstructured support whiskers bearing nanoscopic catalyst particles; wherein the catalyst comprises platinum and manganese and at least one other metal selected from the group consisting of Group VIb metals, Group VIIb metals and Group VIIIb metals other than platinum and manganese; wherein the volume ratio of platinum to the sum of all other metals in the catalyst is between about 1 and about 4, more typically between 1 and 4, more typically between about 2.5 and about 3.5, more typically between 2.5 and 3.5, and most typically about 3, and wherein the Mn content is equal to or greater than about 5 micrograms/cm2 areal density. Typically, the volume ratio of manganese to the at least one other metal is between 10:90 and 90:10. In one embodiment, the volume ratio of platinum to manganese to the at least one other metal is about 6:1:1. Typically, the at least one other metal is Ni or Co.

Abstract: A method is provided for making a supported catalyst comprising nanostructured elements which comprise microstructured support whiskers bearing nanoscopic catalyst particles, where the method comprises the step of depositing a catalyst material comprising at least three metallic elements on microstructured support whiskers from a single target comprising at least three metallic elements. Typically, at least one of said metallic elements is Pt. In addition, one or more of said metallic elements may be Mn, Ni or Co. Other metallic elements or other transition metal elements may be included. In addition, the present invention provides a supported catalyst comprising nanostructured elements which comprise microstructured support whiskers bearing nanoscopic catalyst particles made according to the method of the present invention. Further, the present invention provides fuel cell membrane electrode assembly comprising the supported catalyst according to the present invention.

Abstract: Processes for extending the length of nanostructured support elements of thin film layers are described. The processes involve the initial formation nanostructured support elements during a first annealing step. A coating of material is deposited on the nanostructured support elements. During a second annealing step the initially formed nanostructured support elements longitudinally extend. Longer nanostructured support elements provide increased surface area for supporting catalyst material, thus allowing higher catalyst loading across the layer. Layers having extended nanostructured support elements are particularly useful for electrochemical devices such as fuel cells where catalyst activity is related to the surface area available to support the catalyst.