Abstract: Simplified methods are disclosed for preparing a catalyst coated membrane that is reinforced with a porous polymer sheet (e.g. an expanded polymer sheet) for use in solid polymer electrolyte fuel cells. The methods involve forming a solid polymer electrolyte membrane by coating membrane ionomer solution onto a first catalyst layer and then applying the porous polymer sheet to the membrane ionomer solution coating, while it is still wet, such that the membrane ionomer solution only partially fills the pores of the porous polymer sheet. A second catalyst ink is then applied which fills the remaining pores of the porous polymer sheet. Not only are such methods simpler than many conventional methods, but surprisingly this can result in a marked improvement in fuel cell performance characteristics.

Abstract: A membrane electrode assembly for a fuel cell, with a membrane, a catalyst layer (16) and a gas diffusion layer. The catalyst layer (16) has a first side facing the membrane and a second side facing the gas diffusion layer. In the catalyst layer (16) an ionomer content increases towards the membrane. The catalyst layer (16) has a first sublayer (22) in which catalyst particles (26) are coated with a first ionomer (28). The catalyst layer (16) further has a second sublayer (24) with a second ionomer (32) which is closer to the membrane than the first sublayer (22). Pores (30) are present at least between the coated catalyst particles (26). Further, a method for preparing such a membrane electrode assembly, a fuel cell system and a vehicle with a fuel cell system.

Abstract: Simplified methods for preparing a catalyst coated membrane (CCM) for solid polymer electrolyte fuel cells. The CCM has two reinforcing, expanded polymer sheets and the methods involve forming the electrolyte membrane from ionomer solution during assembly of the CCM. Thus, the conventional requirement to obtain, handle, and decal transfer solid polymer sheets in CCM preparation can be omitted. Further, CCM structures with improved mechanical strength can be prepared by orienting the expanded polymer sheets such that the stronger tensile strength direction of one is orthogonal to the other. Such improved CCM structures can be fabricated using the simplified methods.

Abstract: Simplified methods are disclosed for preparing a catalyst coated membrane that is reinforced with a porous polymer sheet (e.g. an expanded polymer sheet) for use in solid polymer electrolyte fuel cells. The methods involve forming a solid polymer electrolyte membrane by coating membrane ionomer solution onto a first catalyst layer and then applying the porous polymer sheet to the membrane ionomer solution coating, while it is still wet, such that the membrane ionomer solution only partially fills the pores of the porous polymer sheet. A second catalyst ink is then applied which fills the remaining pores of the porous polymer sheet. Not only are such methods simpler than many conventional methods, but surprisingly this can result in a marked improvement in fuel cell performance characteristics.

Abstract: The performance of a solid polymer membrane electrolyte fuel cell under various operating conditions can be improved via use of electrodes comprising multiple layers of supported catalyst in which the layers comprise different catalyst loadings on their respective supports. Such an electrode comprises a first component catalyst layer adjacent the membrane electrolyte and a second component catalyst layer adjacent the first component layer. The loading of the catalyst in the first component layer is greater than that in the second component layer.

Abstract: Use of noble metal alloy catalysts, such as PtCo, as the cathode catalyst in solid polymer electrolyte fuel cells can provide enhanced performance at low current densities over that obtained from the noble metal itself. Unfortunately, the performance at high current densities has been relatively poor. However, using a specific bilayer cathode construction, in which a noble metal/non-noble metal alloy layer is located adjacent the cathode gas diffusion layer and a noble metal layer is located adjacent the membrane electrolyte, can provide superior performance at all current densities.

Abstract: In solid polymer electrolyte fuel cells, an oxygen evolution reaction (OER) catalyst may be incorporated at the anode along with the primary hydrogen oxidation catalyst for purposes of tolerance to voltage reversal. Incorporating this OER catalyst in a layer at the interface between the anode's primary hydrogen oxidation anode catalyst and its gas diffusion layer can provide greatly improved tolerance to voltage reversal for a given amount of OER catalyst. Further, this improvement can be gained without sacrificing cell performance.

Abstract: Simplified methods for preparing a catalyst coated membrane (CCM) for solid polymer electrolyte fuel cells. The CCM has two reinforcing, expanded polymer sheets and the methods involve forming the electrolyte membrane from ionomer solution during assembly of the CCM. Thus, the conventional requirement to obtain, handle, and decal transfer solid polymer sheets in CCM preparation can be omitted. Further, CCM structures with improved mechanical strength can be prepared by orienting the expanded polymer sheets such that the stronger tensile strength direction of one is orthogonal to the other. Such improved CCM structures can be fabricated using the simplified methods.

Abstract: A membrane electrode assembly for a fuel cell is disclosed, which comprises at least one porous ionomer containing layer disposed at the interface between the cathode electrocatalyst material and the ion exchange membrane of the fuel cell. The porous ionomer containing layer comprises a catalyst migration impeding compound. The membrane electrode assembly exhibits improved stability against Pt dissolution and Pt-band formation within the ion exchange membrane, hence having improved durability and lifetime performance.

Abstract: A membrane electrode assembly for a fuel cell, with a membrane, a catalyst layer (16) and a gas diffusion layer. The catalyst layer (16) has a first side facing the membrane and a second side facing the gas diffusion layer. In the catalyst layer (16) an ionomer content increases towards the membrane. The catalyst layer (16) has a first sublayer (22) in which catalyst particles (26) are coated with a first ionomer (28). The catalyst layer (16) further has a second sublayer (24) with a second ionomer (32) which is closer to the membrane than the first sublayer (22). Pores (30) are present at least between the coated catalyst particles (26). Further, a method for preparing such a membrane electrode assembly, a fuel cell system and a vehicle with a fuel cell system.

Abstract: Ligand additives having two or more coordination sites in close proximity can be used in the polymer electrolyte of membrane electrode assemblies in solid polymer electrolyte fuel cells in order to reduce the dissolution of catalyst, particularly from the cathode, and hence reduce fuel cell degradation over time.

Abstract: Use of noble metal alloy catalysts, such as PtCo, as the cathode catalyst in solid polymer electrolyte fuel cells can provide enhanced performance at low current densities over that obtained from the noble metal itself. Unfortunately, the performance at high current densities has been relatively poor. However, using a specific bilayer cathode construction, in which a noble metal/non-noble metal alloy layer is located adjacent the cathode gas diffusion layer and a noble metal layer is located adjacent the membrane electrolyte, can provide superior performance at all current densities.

Abstract: In solid polymer electrolyte fuel cells, an oxygen evolution reaction (OER) catalyst may be incorporated at the anode along with the primary hydrogen oxidation catalyst for purposes of tolerance to voltage reversal. Incorporating this OER catalyst in a layer at the interface between the anode's primary hydrogen oxidation anode catalyst and its gas diffusion layer can provide greatly improved tolerance to voltage reversal for a given amount of OER catalyst. Further, this improvement can be gained without sacrificing cell performance.

Abstract: Ligand additives having two or more coordination sites in close proximity can be used in the polymer electrolyte of membrane electrode assemblies in solid polymer electrolyte fuel cells in order to reduce the dissolution of catalyst, particularly from the cathode, and hence reduce fuel cell degradation over time.

Abstract: The present disclosure relates to a catalyst including platinum phosphide having a cubic structure, a method of making the catalyst, and a fuel cell utilizing the catalyst. The present disclosure also relates to method of making electrical power utilizing a PEMFC incorporating the catalyst. Also disclosed herein is a catalyst including a platinum complex wherein platinum is complexed with a nonmetal or metalloid. The catalyst with the platinum complex can exhibit good electro-chemically active properties.

Abstract: A membrane electrode assembly for a fuel cell is disclosed, which comprises at least one porous ionomer containing layer disposed at the interface between the cathode electrocatalyst material and the ion exchange membrane of the fuel cell. The porous ionomer containing layer comprises a catalyst migration impeding compound. The membrane electrode assembly exhibits improved stability against Pt dissolution and Pt-band formation within the ion exchange membrane, hence having improved durability and lifetime performance.

Abstract: Fluorination of a porous hydrocarbon-based polymer for use as a composite membrane and, more particularly, for use as a composite proton exchange membrane for a fuel cell. The composite membrane is formed by fluorination of the porous hydrocarbon-based polymer to yield a selectively fluorinated polymer, which is then loaded with an ionomer to yield the composite membrane.

Abstract: An electrocatalyst composition for use in an electrochemical fuel cell is disclosed. The electrocatalyst composition comprises (1) an electrocatalyst support comprising a carbon-containing species and at least one hydrogen peroxide and/or oxygen radical decomposition catalyst, and (2) a noble metal electrocatalyst supported on the electrocatalyst support. In addition, the at least one hydrogen peroxide and/or oxygen radical decomposition catalyst comprises transition metal inclusions within the electrocatalyst support, and the electrocatalyst support does not comprise any nitrogen-containing species or metal oxides.

Abstract: A water insoluble additive for improving the performance of an ion-exchange membrane, such as in the context of the high temperature operation of electrochemical fuel cells. The insoluble additive comprises a metal oxide cross-linked matrix having proton conducting groups covalently attached to the matrix through linkers. In one embodiment, the metal is silicon and the cross-linked matrix is a siloxane cross-linked matrix containing silicon atoms cross-linked by multiple disiloxy bonds and having proton conducting groups covalently attached to the silicon atoms through alkanediyl linkers.

Abstract: A significant problem in PEM fuel cell durability is in premature failure of the ion-exchange membrane and in particular by the degradation of the ion-exchange membrane by reactive hydrogen peroxide species. Such degradation can be reduced or eliminated by the presence of an additive in the anode, cathode or ion-exchange membrane. The additive may be a radical scavenger, a membrane cross-linker, a hydrogen peroxide decomposition catalyst and/or a hydrogen peroxide stabilizer. The presence of the additive in the membrane electrode assembly (MEA) may however result in reduced performance of the PEM fuel cell. Accordingly, it may be desirable to restrict the location of the additive to locations of increased susceptibility to membrane degradation such as the inlet and/or outlet regions of the MEA.