Abstract: A component for use in assembling a membrane electrode assembly comprises a microporous layer supported on a transfer substrate, wherein the microporous layer comprises carbon particles and a hydrophobic polymer, and a polymer layer is present on the microporous layer. A process for preparing a component for use in assembling a membrane electrode assembly includes forming the microporous layer on the transfer substrate and applying a polymer layer on the microporous layer. The microporous layer may also be deposited onto a gas diffusion substrate for use in the membrane electrode assembly.

Abstract: A catalyst layer including: (i) a first catalytic material, wherein the first catalytic material facilitates a hydrogen oxidation reaction suitably selected from platinum group metals, gold, silver, base metals or an oxide thereof; and (ii) a second catalytic material, wherein the second catalytic material facilitates an oxygen evolution reaction, wherein the second catalytic material includes iridium or iridium oxide and one or more metals M or an oxide thereof, wherein M is selected from the group consisting of transition metals and Sn, wherein the transition metal is preferably selected from the group IVB, VB and VIB; and the first catalytic material is supported on the second catalytic material. The catalyst can be used in fuel cells, supported on electrodes or polymeric membranes for increasing tolerance to cell voltage reversal.

Abstract: A sealed and/or reinforced membrane electrode assembly is disclosed. Encapsulation films, each comprising a backing layer and an adhesive layer, are positioned on the edges of at least one face of each gas diffusion substrate such that the adhesive layers impregnate into each gas diffusion substrate. Methods of forming sealed and/or reinforced membrane electrode assemblies are also disclosed.

Abstract: A reinforced membrane comprises: (I) a planar reinforcing component made from metal, carbon, polymer or a composite thereof, and (ii) an ion-conducting material, wherein the planar reinforcing component is a cellular structure, comprising a plurality of discrete cells, wherein the wall of each cell extends through the thickness of the component such that the cell wall is impermeable to the proton-conducting material and wherein the proton-conducting material fills the cells of the planar reinforcing component. Such a membrane is of use in a fuel cell or an electrolyser.

Abstract: A sealed and/or reinforced membrane electrode assembly is disclosed. Encapsulation films, each comprising a backing layer and an adhesive layer, are positioned on the edges of at least one face of each gas diffusion substrate such that the adhesive layers impregnate into each gas diffusion substrate. Methods of forming sealed and/or reinforced membrane electrode assemblies are also disclosed.

Abstract: A porous catalyst layer formed from discrete particles of unsupported metal, wherein at least 80%, suitably at least 90%, of the discrete particles have a mass of from 1 to 1000 zeptograms, and wherein the catalyst layer has a metal volume fraction of less than 30% and a metal loading of less than 0.09 mg/cm2 is disclosed. The catalyst layer is suitable for use in fuel cells and other electrochemical applications.

Abstract: A reinforced catalyst layer assembly, suitably for use in a fuel cell, said reinforced catalyst layer assembly comprising: (i) a planar reinforcing component consisting of a porous material having pores extending through the thickness of the material in the z-direction, and (ii) a first catalyst component comprising a first catalyst material and a first ion-conducting material, characterised in that the first catalyst component is at least partially embedded within the planar reinforcing component, forming a first catalyst layer having a first surface and a second surface is disclosed.

Abstract: An MEA comprising: (i) a central first conductive gas diffusion substrate having a first face and a second face; (ii) first and second catalyst layers each having a first and second face and wherein the first face of the first catalyst layer is in contact with the first face of the gas diffusion substrate and the first face of the second catalyst layer is in contact with the second face of the gas diffusion substrate; (iii) first and second electrolyte layers each having a first and second face and wherein the first face of the first electrolyte layer is in contact with the second face of the first catalyst layer and the first face of the second electrolyte layer is in contact with the second face of the second catalyst layer; (iv) third and fourth catalyst layers each having a first and second face and wherein the first face of the third catalyst layer is in contact with the second face of the first electrolyte layer and the first face of the fourth catalyst layer is in contact with the second face of the se

Abstract: A sealed and/or reinforced membrane electrode assembly is disclosed. Encapsulation films, each comprising a backing layer and an adhesive layer, are positioned on the edges of at least one face of each gas diffusion substrate such that the adhesive layers impregnate into each gas diffusion substrate. Methods of forming sealed and/or reinforced membrane electrode assemblies are also disclosed.

Abstract: A catalyst layer includes (i) an electrocatalyst, and (ii) a water electrolysis catalyst, iridium or iridium oxide and one or more metals M or an oxide thereof, wherein M is selected from transition metals and/or Sn, with the exception of ruthenium. Such a catalyst layer has utility in fuel cells that experience high electrochemical potentials.

Abstract: A gas diffusion substrate includes a non-woven network of carbon fibres, the carbon fibres are graphitised but the non-woven network has not been subjected to a graphitisation process. A mixture of graphitic particles and hydrophobic polymer is disposed within the network. The longest dimension of at least 90% of the graphitic particles is less than 100 ?m. A process for manufacturing gas diffusion substrates includes depositing a slurry of graphitised carbon fibres onto a porous bed forming a wet fibre network, preparing a suspension of graphitic particles and hydrophobic polymer, applying onto, and pulling the suspension into, the network, and drying and firing the network. Another process includes mixing a first slurry of graphitic particles and hydrophobic polymer with a second slurry of graphitised carbon fibres and liquid forming a third slurry, depositing the third slurry onto a porous bed forming a fibre-containing layer, and drying and firing the layer.

Abstract: A porous catalyst layer formed from discrete particles of unsupported metal, wherein at least 80%, suitably at least 90%, of the discrete particles have a mass of from 1 to 1000 zeptograms, and wherein the catalyst layer has a metal volume fraction of less than 30% and a metal loading of less than 0.09 mg/cm2 is disclosed. The catalyst layer is suitable for use in fuel cells and other electrochemical applications.

Abstract: An MEA comprising: (i) a central first conductive gas diffusion substrate having a first face and a second face; (ii) first and second catalyst layers each having a first and second face and wherein the first face of the first catalyst layer is in contact with the first face of the gas diffusion substrate and the first face of the second catalyst layer is in contact with the second face of the gas diffusion substrate; (iii) first and second electrolyte layers each having a first and second face and wherein the first face of the first electrolyte layer is in contact with the second face of the first catalyst layer and the first face of the second electrolyte layer is in contact with the second face of the second catalyst layer; (iv) third and fourth catalyst layers each having a first and second face and wherein the first face of the third catalyst layer is in contact with the second face of the first electrolyte layer and the first face of the fourth catalyst layer is in contact with the second face of the se

Abstract: A component for use in assembling a membrane electrode assembly comprises a microporous layer supported on a transfer substrate, wherein the microporous layer comprises carbon particles and a hydrophobic polymer, and a polymer layer is present on the microporous layer. A process for preparing a component for use in assembling a membrane electrode assembly includes forming the microporous layer on the transfer substrate and applying a polymer layer on the microporous layer. The microporous layer may also be deposited onto a gas diffusion substrate for use in the membrane electrode assembly.

Abstract: A gas diffusion substrate includes a non-woven network of carbon fibres, the carbon fibres are graphitised but the non-woven network has not been subjected to a graphitisation process. A mixture of graphitic particles and hydrophobic polymer is disposed within the network. The longest dimension of at least 90% of the graphitic particles is less than 100 ?m. A process for manufacturing gas diffusion substrates includes depositing a slurry of graphitised carbon fibres onto a porous bed forming a wet fibre network, preparing a suspension of graphitic particles and hydrophobic polymer, applying onto, and pulling the suspension into, the network, and drying and firing the network. Another process includes mixing a first slurry of graphitic particles and hydrophobic polymer with a second slurry of graphitised carbon fibres and liquid forming a third slurry, depositing the third slurry onto a porous bed forming a fibre-containing layer, and drying and firing the layer.