NOVELTY - The production of a catalyst layer comprises depositing an ink composition onto a substrate, the composition comprising a liquid vehicle, a particulate support phase and a molecular precursor to an active species phase; and heating the ink composition to not more than 200degreesC to convert the molecular precursor to an active species phase dispersed on the support phase and form a catalyst layer.    USE - Used for the production of a catalyst layer used in manufacture of an electrode for proton exchange membrane and direct methanol fuel cell (claimed).    ADVANTAGE - The method enables rapid production of the membrane electrode assemblies (MEA) (200) and layers with controlled properties and improved performance.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following:    (a) an ink composition useful for the formation of a catalyst layer, comprising a liquid vehicle; a molecular precursor to an active species phase; and particulate carbon;    (b) the manufacture of an electrode for a fuel cell, comprising depositing a first ink composition on at least a portion of a substrate to form a first material layer, the first ink composition comprising first material from electrocatalyst particles, proton conducting polymer, hydrophobic material or particulate carbon; depositing a second ink composition on portion of the first material layer, where the second ink composition comprises the first material in a concentration that is different than the concentration of the first material in the first ink composition;    (c) an electrode for a direct methanol fuel cell, comprising a proton exchange membrane; a first electrocatalyst layer (220) comprising first electrocatalyst particles on the proton exchange membrane; a second electrocatalyst layer (222) comprising second electrocatalyst particles on the first electrocatalyst layer, where the second electrocatalyst particles have an average particle size that is larger than the first electrocatalyst particles; and a fluid distribution layer (206, 212) over the second electrocatalyst layer;    (d) the manufacture of a membrane electrode sub-assembly, comprising providing an ion exchange membrane having mutually opposed first and second sides; and depositing a first ink composition comprising an electrocatalyst onto a first side of the ion exchange membrane using a direct-write tool to form a first material layer;    (e) the manufacture of a liquid diffusion layer in a direct methanol fuel cell electrode, comprising providing an ink composition comprising a hydrophobic material; and depositing the ink composition onto a methanol fuel cell electrode;    (f) the deposition of electrocatalyst layers on an ion exchange membrane, comprising providing an ion exchange membrane having opposed first and second surfaces; moving the ion exchange membrane to a position disposed between first and second direct-write tools; depositing a first ink composition on the first surface using the first direct-write tool; depositing a second ink composition on the second surface using the second direct-write tool; and drying the first and second deposited ink compositions to form electrocatalyst layers on the opposed first and second surfaces;    (g) the production of an electrocatalyst layer, comprising depositing an ink precursor composition onto a substrate, the ink composition comprising a liquid vehicle, particulate carbon and a molecular precursor to an active species phase; and reacting the precursor composition with a reducing agent to convert the active species phase precursor to an active species phase and form an electrocatalyst layer; and    (h) the production of a catalyst layer, comprising depositing an ink composition onto a substrate, the ink composition comprising a liquid vehicle, a first particulate material and a second particulate material comprising nanoparticles; and converting the ink composition into an catalyst layer.    DESCRIPTION OF DRAWING(S) - The figure illustrates a cross-sectional view of an MEA.    MEA (200)    Fluid distribution layer (206, 212)    Bipolar plates (208)    First electrocatalyst layer (220)    Second electrocatalyst layer (222)