Influence of preparative procedure on the activity and selectivity of FeZSM-5 catalysts in syngas conversion

• Published in: Applied catalysis 1986-10, Vol.27 (1), p.55-68
• Main Authors: Shamsi, A., Rao, V.U.S., Gormley, R.J., Obermyer, R.T., Schehl, R.R., Stencel, J.M.
• Format: Article
• Language: English
• Subjects: Catalysis; Catalysts: preparations and properties; Catalytic reactions; Chemistry; Exact sciences and technology; General and physical chemistry; General. Nomenclature, chemical documentation, computer chemistry; Theory of reactions, general kinetics; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
• ISSN: 0166-9834
• DOI: 10.1016/S0166-9834(00)81046-5

The ZSM-5 supported iron catalysts have been investigated with respect to physical and chemical properties and to activity and product selectivity for conversion of synthesis gas to hydrocarbon products. The catalyst preparations consisted of (1) direct decomposition of (C5H5Fe(CO)2)2 on ZSM-5, (2) impregnation of ZSM-5 with an aqueous solution of iron nitrate, and (3) physical admixture of precipitated iron oxide with ZSM-5. Some H2 and CO chemisorption studies and magnetization measurements were conducted to measure the average metal crystallite size. At the metal loading of about 8 wt%, the catalysts prepared by the first method produced higher metal dispersion compared to the other two methods of preparation, although the amount of aromatic compounds in liquid hydrocarbon products was very low. Infrared studies of chemisorbed pyridine on these samples indicate that ion exchange of Fen+ for acidic protons occurs in aqueous solution impregnated catalysts, while no ion exchange is found in organometallic impregnated or physically admixed catalysts.