Micro-contact printing on oxide surfaces for model catalysts using e-beam written masters in hydrogen silsesquioxane

In order to make model catalysts for fundamental research in heterogeneous catalysis, carrier oxide surfaces with well-defined properties are needed. Micro-contact printing has been used to make specific parts of a (hydroxylated) silicon oxide surface hydrophobic. The method comprises the e-beam writing of a master in hydrogen silsesquioxane (HSQ) on silicon, the casting of a polydimethylsiloxane (PDMS) silicone elastomer stamp, the inking of the stamp with octadecyltrichlorosilane (OTS) and the printing of the OTS on a hydroxylated SiO2 surface. KCl crystals have been precipitated on the hydrophilic part of the printed surface by evaporation of ethanol droplets with dissolved KCl. KCl serves as a model system for the usual transition metal salts employed in the preparation of metal- or metal-oxide catalysts. Crystal size and crystallite density-on-carrier can be determined by the duty cycle and pitch of the hydrophilic part of the printed surface. (C) 2004 Elsevier B.V. All rights reserved.