Promoting effect of Fe on Pt/ZSM-5 catalysts for propane dehydrogenation

Propane dehydrogenation (PDH) is an attractive method for propylene production. PtxFe/ZSM-5 catalysts were prepared by the sequential incipient wetness impregnation of Fe and Pt on ZSM-5 support. The promoting effect of Fe on the catalytic performance of PtxFe/ZSM-5 during propane dehydrogenation reaction was studied. Various characterization techniques including N2 adsorption/desorption, ICP-OES, HRTEM, XPS, CO-DRIFT and TG were employed to unravel the properties of the catalysts. The experimental results confirmed the importance of Fe as a promotor in PDH. Suitable loading of Fe could obviously improve propane conversion, propylene selectivity, and the anti-coking ability of the catalysts, while excessive Fe caused metal aggregation and promoted side reactions, leading to a decreased propylene selectivity. When Fe loading was 1.0 %, the resulting Pt1.0Fe/ZSM-5 exhibited the best catalytic performance (propane conversion = 47.1 %, and propylene selectivity = 78.9 %), and it also showed good catalytic stability after regeneration. Pt0.5Fe/ZSM-5 showed the lowest coke amount of 0.10 gc & sdot;gcat- 1, and the addition of 0.5 % Fe in Pt/ZSM-5 catalyst decreased 61.5 % of coke deposits.