Different synthesis methods (seeded and unseeded liquid phase hydrothermal synthesis, steam-assisted crystallization) have been employed to prepare zeolite films as catalytic coatings on the channels of stainless steel microreactors. The best results were obtained using seeded steam-assisted crystallization (SAC) which under suitable conditions led to well-crystallized zeolite films whose growth was confined to the channel spaces. Liquid phase synthesis yielded higher catalyst loads but was less effective in confining crystal growth to the desired regions. Once the zeolite films were formed, conventional ion-exchange procedures were used to produce a homogeneous distribution of Pt in the zeolite films. (c) 2007 Elsevier B.V. All rights reserved.