Zeolite/sintered metal fibers composites as effective structured catalysts

The catalytic filters of sintered metal fibers (SMF) coated by thin MFI-type zeolite (silicalite-1, ZSM-5) films have been synthesized and tested in the reactor with structured catalytic bed. The catalysts show multifunctional behavior, combining catalysis with heat exchange, mixing, and particulates removal. The reactors based on the zeolite/SMF composite elements have a three-level structure: (i) a micro-scale due to oriented submicron zeolite crystals; (ii) a meso-scale due to homogeneous porosity of metal fiber filters; (iii) a macro-scale due to the design characteristics of the catalyst packing. The catalytic bed of the FeZSM-5/SMFFecralloy was efficient and the one-step benzene hydroxylation to phenol with N2O at temperatures as low as 270 °C without loosing N2O via decomposition to nitrogen and oxygen (selectivity close to 100%). The catalyst was effective in the N2O decomposition at temperatures 400–500 °C.