Although the catalytic studies unde

Although the catalytic studies under several conditions (typical PROX reaction conditions) carried out over the microreactor MR300 were not directed to a systematic analysis of the deactivation processes, the postmortem characterization of such microreactor revealed remarkable and useful details that should be considered for designing new prototypes.Detachment and migration of the catalytic layer were observed after the prolonged use of the microreactor MR300. Thus the anchoring of the catalyst to the walls of the microchannels has been insufficient, which seemed to be as important as the deactivation of the active sites of the catalyst itself. One of main causes is the degradation of the steel of the metallic substrate by migration of metallic cations to the surface due to the influence of the feedstream. The migration of species to the joining area between thecatalyst and the structured reactor weakened such interaction, even breaking the catalytic layer. This phenomenon was observed although the microreactor was thermally pretreated (prior to the washcoating of the catalytic layer) in order to produce a protectivelayer of alumina that also enhanced the anchoring of the catalyst. In this sense the thickness of such protective layer would not have been enough for avoiding migration of metallic species from the core of the metallic substrate to the surface.