Oxidative Dehydrogenation of Isobutane to Isobutene on FSM-16 Doped with Cr and Related Catalysts

The oxidative dehydrogenation of isobutane to isobutene was examined for the use in the preparation of FSM-16 and related compounds doped by chromium with expectations that a yield of isobutene of greater than 8% could be achieved. The activity depended on the molding procedure of the catalyst and the doping method of the chromium species. In the present study, 8.8% and 8.3% of the yield of isobutene were obtained at 0.75 h and 6 h on-stream for the catalyst （Cr-loading; 6.2 wt.%） molded using wet treatment hut not pressurization treatment, in which the chromium species were directly added into the aqueous solution containing raw FSM-16 （hydrated sodium silicate powder） at an initial stage of the catalyst preparation. The structure information was based on XRD （X-ray diffraction）, the specific surface area was determined using a conventional BET （Brunauer-Emmett-Teller） nitrogen adsorption and the loading of chromium was estimated using ICP （inductively coupled plasma）. All those parameters combined with the molding method indicated that the catalytic activity was more influenced by the loading of chromium into bulk but not on surface of the catalyst rather than by the hexagonal structure of FSM-16 and the surface area.