TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The substrate permeable to the gas is a substrate of glass, ceramic and/or hybrid, amorphous or crystalline, present in the form of fibrous, foam, honeycomb (preferred), porous materials, from the structures of particulate filters or monoliths. The substrate is a fibrous amorphous substrate of silicon or glass, preferably glass of amorphous silica or glass having more than 90 wt.% of silica. The gas permeable substrate is fiber assemblies comprising filaments, fabrics, knitted fabrics, braids, mats, cloth, felt, wool, batting, chopped strand, filament winding or non-woven structures. The mesoporous coating is: based on at least a compound comprising an oxide, carbide or nitride of at least a elements of silicon, tungsten, antimony, titanium, zirconium, tantalum, vanadium, boron, lead, magnesium, aluminum, manganese, cobalt, nickel, tin, zinc, indium, iron, molybdenum, barium and cerium; and is a coating comprising oxides of silica, aluminum oxide, zirconium oxide, iron oxides, cerium oxide, barium oxides and mixed oxides of the latter, where the mesoporous coating is particularly a coating of silica. The pore size of the mesoporous coating is 2-50 nm, preferably 2-6 nm. The catalytic elements are transition metals and compounds comprising oxides and transition metals, where the catalytic elements are platinum, palladium, gold, iridium, osmium, rhodium, barium, rhenium, silver, silicon, tungsten, antimony, titanium, zirconium, tantalum, vanadium, boron, lead, magnesium, aluminum, manganese, cobalt, nickel, tin, zinc, indium, iron, molybdenum, barium, cerium and chromium. The metal content of the catalytic elements is 0.05-4 wt.%, preferably 0.05-0.15 wt.% of the material. The aqueous solution has a pH of 8-10. The material has: a specific surface of at least equal to 10 m2/g, preferably at least equal to 150 m2/g. The mesoporous coating has a thickness of 0.02-2.5 microns, preferably 0.1-1 micron. EXAMPLE - No suitable example given.