A method for producing a catalyst system for gas reactions, comprising at least one noble metal fabric that comprises gas-permeable openings, the method comprising the steps of: providing at least one noble metal powder consisting of at least substantially spherical noble metal particles, and repeatedly applying in layers the noble metal powder or powders provided in step to a substrate in a build chamber, followed in each case by at least partially melting the relevant noble metal powder applied as a layer using high-energy radiation, and allowing the melted noble metal powder to solidify as part of an additive manufacturing process, wherein the or each noble metal fabric comprising gas-permeable openings comprises an individual weight per unit area in the range of 25 to 2500 g/m 2, wherein at least 80 % of the noble metal particles, based on their quantity, satisfy the condition 0.8 ≤ d min / d max ≤ 1.0, where d min is the minimum diameter and d max is the maximum diameter of an individual noble metal particle, and wherein the noble metal particles of the noble metal powder or powders comprise a particle size distribution having a d 10 value of ≥ 5 μm and a d 90 value of ≤ 80 μm, wherein the particle size distribution in the form of a mass distribution sum curve is determined by laser diffraction, and wherein the noble metal of the noble metal particles of the noble metal powder or powders is selected from the group consisting of noble metal alloys of platinum with 1-15 wt.% rhodium, platinum with 2-15 wt.% rhodium and 0.1-20 wt.% palladium, platinum with 2-15 wt.% rhodium, 0.1-20 wt.% palladium, and 0.1-2 wt.% ruthenium, platinum with 2-15 wt.% rhodium, 0.1-20 wt.% palladium, and 0.1-5 wt.% iridium, palladium with 3-15 wt.% platinum, palladium with 1-20 wt.% platinum and 1-10 wt.% rhodium, palladium with 1-25 wt.% tungsten, and palladium with 1-15 wt.% nickel. providing at least one noble metal powder consisting of at least substantially spherical noble metal particles, and repeatedly applying in layers the noble metal powder or powders provided in step to a substrate in a build chamber, followed in each case by at least partially melting the relevant noble metal powder applied as a layer using high-energy radiation, and allowing the melted noble metal powder to solidify as part of an additive manufacturing process, wherein the or each noble metal fabric comprising gas-permeable openings comprises an individual weight per unit area in the range of 25 to 2500 g/m 2, wherein at least 80 % of the noble metal particles, based on their quantity, satisfy the condition 0.8 ≤ d min / d max ≤ 1.0, where d min is the minimum diameter and d max is the maximum diameter of an individual noble metal particle, and wherein the noble metal particles of the noble metal powder or powders comprise a particle size distribution having a d 10 value of ≥ 5 μm and a d 90 value of ≤ 80 μm, wherein the particle size distribution in the form of a mass distribution sum curve is determined by laser diffraction, and wherein the noble metal of the noble metal particles of the noble metal powder or powders is selected from the group consisting of noble metal alloys of platinum with 1-15 wt.% rhodium, platinum with 2-15 wt.% rhodium and 0.1-20 wt.% palladium, platinum with 2-15 wt.% rhodium, 0.1-20 wt.% palladium, and 0.1-2 wt.% ruthenium, platinum with 2-15 wt.% rhodium, 0.1-20 wt.% palladium, and 0.1-5 wt.% iridium, palladium with 3-15 wt.% platinum, palladium with 1-20 wt.% platinum and 1-10 wt.% rhodium, palladium with 1-25 wt.% tungsten, and palladium with 1-15 wt.% nickel.