Stainless steel (flat and microstructured) substrates have been coated with sol-gel catalysts made up of metal nanoparticles (Rh, Ni, Pt) 19 dispersed on alumina and alumina-ceria supports. The aluminum monohydroxyde (boehmite) sols were synthesized by hot hydrolysis/peptization of an aluminum alkoxide (Yoldas method). It is shown that the rheological properties of the sol, especially the thixotropy, play a key role on the homogeneity and the quality of the film deposited on the metal substrate. The catalyst layers have a very good adhesion, a thickness which can be easily controlled (in the range 0.1 to 10 mu m), a large specific surface area and a good mechanical and thermal stability. (c) 2005 Elsevier B.V. All rights reserved.