Method for control of the thickness of mesoporous titania films for applications in catalytic microreactors

Mesoporous titania films with a long-order structure were obtained on silicon and metal substrates. Control of the thickness of the titania film was achieved by multiple spin-coating. Successful control of the film thickness in the range of 300 to 1000 nm is considered an important step toward application in microstructured reactors, as well as for basic research on model catalysts. After doping the Ti sol with gold nanoparticles, the resulting catalysts were tested in the hydrogenation of citral. The reaction occurred in the kinetic regime at a coating thickness of 300 nm, while thicker films demonstrated severe internal diffusion limitations