The suppression of coke deposition by the modification of Mn on Fe/silicalite-2 catalyst in dehydrogenation of C2H6 with CO2 Original Research Article

For the dehydrogenation of C2H6 with CO2 to C2H4, a silicalite-2 zeolite supported Fe–Mn catalyst has been developed, with an achievement of 93% of C2H4 selectivity and 66% of C2H6 conversion. The promotion of Mn to the Fe/Si-2 catalyst lies not only in increasing C2H4 selectivity but also in improving the catalytic stability greatly. A thermo-balance was employed to investigate the behavior of coke deposition on Fe/silicalite-2 and Fe–Mn/silicalite-2 catalysts during C2H6 dehydrogenation. By studying the effects of reaction temperature and partial pressures of C2H6 and CO2 on coke deposition, the kinetic parameters of the coking reaction were satisfied and the corresponding coking reaction kinetics equations were thus established. The rate of coke deposition on Fe–Mn/silicalite-2 is much less than that on Fe/silicalite-2, due to the modification of Mn to the Fe/silicalite-2 catalyst. The promotion of Mn to the improvement of the catalytic stability of the Fe/silicalite-2 catalyst results from the great prohibition of coke formation on Fe–Mn/silicalite-2 catalyst surfaces.