The invention concerns a method for producing a highly-porous ceramic layer and for application of this layer onto metallic, ceramic, enameled and/or glass substrates using porous, ceramic particles, preferably aluminum oxide, titanium oxide and zircon oxide, and an inorganic binder system. The inorganic binder system contains at least one ceramic nanoparticle of a particle size of less than 100 nm, preferably less than 50 nm and particularly preferred less than 25 nm, the solvent being water. Layers produced in this fashion are suited as self-cleaning catalytically active layers e.g. in ovens, in combustion engines etc. or for general coating of substances to considerably increase their specific surface e.g. for catalytic substrates.