Propane oxydehydrogenation over transition metal modified zeolite ZSM-5

Zeolite ZSM-5 of Si/Al ratio from 14 to 100, modified with transition metal ions (Fe3+, Mn2+, Co2+) introduced by means of ionic exchange, showed catalytic activity for propane oxidation already at 330degreesC. The use of air as oxidant resulted mainly in carbon oxides, while application of N2O led to high selectivity towards propene. Thermal treatment of modified zeolites was a crucial parameter influencing an oxidative activity of the samples. High activity for propane oxydehydrogenation was found for samples calcined at 900degreesC, while the calcination at lower temperature (600degreesC) resulted in negligible propane conversion. Presence of MFI structure appeared indispensable for the formation of active transition metal complexes, while Si/Al ratio influenced activity and selectivity of catalysts less significantly. (C) 2002 Published by Elsevier Science B.V.