NOVELTY - A fuel cell assembly comprises first and second matrices having a pore structure to allow gas permeation within the matrix and water exudation out of the matrix, and containing particulate carbon. At least a portion of each of the first and the second matrices contain catalytic material-coated particulate carbon to constitute a catalytic portion.    USE - For a fuel cell used with a source of gaseous reductant and a source of gaseous oxidant.    ADVANTAGE - The fuel cell assembly has good electrochemical and mechanical performance and a stabilized current voltage output under varying load conditions.    DETAILED DESCRIPTION - A fuel cell assembly comprises a central ionic membrane having a membrane first surface and a membrane second surface, a first matrix (308) formed of an organic polymer having a first matrix first surface in contact with the membrane first surface and a first matrix second surface, a second matrix (310) formed of an organic polymer having a second matrix first surface in contact with the membrane second surface and a second matrix second surface, a first current collector within the first matrix, and a second current collector within the second matrix and in electrical communication with the first current collector. Each of the first and the second matrices has a pore structure to allow gas permeation within the matrix and water exudation out of the matrix, and contains particulate carbon. At least a portion of each of the first and the second matrices contain catalytic material-coated particulate carbon to constitute a catalytic portion.    INDEPENDENT CLAIMS are also included for:    (1) a method of preparing a fuel cell assembly, comprising embedding the first current collector in the first particulate carbon-containing hydrophobic matrix, embedding the second current collector in the second particulate carbon-containing hydrophobic matrix, locating the central membrane between the first and second matrixes, and treating the first and the second matrixes with a solution of a compound of the catalytic material in an oxidation state to effect reduction to the catalytic material and production of the catalytic material-coated particulate carbon;    (2) a fuel cell comprising the assembly and oxidant feed in communication with the first matrix and reductant feed in communication with the second matrix;    (3) a gas diffusion electrode for use with a fuel cell comprising a matrix formed of an organic polymer having a pore structure to allow of gas permeation within and water exudation out of the matrix, a first surface, a second surface, and a current collector embedded within the matrix, where the matrix contains particulate carbon and at least a portion of the particulate carbon is coated with catalytic material to constitute a catalytic portion.    DESCRIPTION OF DRAWING(S) - The figure shows a section of a membrane electrode assembly.    Membrane electrode assembly (300)    Matrices (308, 310)    Catalysts (312, 314)