Influence of the zeolite synthesis route on its catalytic properties in the methanol to olefin reaction

The influence of the zeolite ZSM-5 synthesis procedure (hydroxide and fluoride route) on its catalytic performances in the methanol to olefin (MTO) reaction has been investigated. ZSM-5 crystals have been successfully coated on pre-shaped SiC foams structured catalysts, being prepared either by the classical alkaline or by the fluoride-mediated route. In addition, a new concept in the preparation of zeolite materials has been employed, so-called in situ zeolite synthesis. The silica superficial layer from the support itself was used as a silica source in this procedure. Moreover, the in situ route avoids addition of any external silicon source. As-prepared structured catalysts have been tested in the conversion of methanol mainly into light olefins (MTO process). Depending on the preparation procedure, structured zeolite catalysts exhibited different performances in terms of activity and selectivity