Abstract: A method for applying porous, preferably catalytically active metal oxide coatings to relatively non-porous substrates in a fibrous form, and the catalyst materials thereby obtained. A solution is formed of one or more hydrolyzable precursors of metal oxides, in an anhydrous, organic solvent. The substrate to be coated, having active surface hydroxyl groups and preferably being glass or ceramic, is dipped into the solution and thereafter removed, drained and dried in an atmosphere containing water vapor so as to form a uniform, and at least partially hydrolyzed metal hydroxide/alkoxide coating on the substrate. The thus coated substrate is cured by heating in one or more stages at temperatures in the range of between about 250.degree. and 500.degree. C. to form an adherent, highly porous coating of the corresponding metal oxide.