The genesis of carbon-supported Fe-Mn and K-Fe-Mn catalysts from stoichiometric metal carbonyl clusters. III. Characterization by chemisorption, calorimetry, and kinetic analysis

Journal Article · Sun Oct 01 04:00:00 EDT 1989 · Journal of Catalysis; (USA)

DOI:https://doi.org/10.1016/0021-9517(89)90174-7· OSTI ID:7089986

Venter, J J; Chen, A A; Phillips, J; Vannice, M A ^[1]

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1. The Pennsylvania State Univ., University Park (USA)

Carbon-supported Fe, Fe-Mn, and K-Fe-Mn catalysts derived from stoichiometric mixed-metal carbonyl clusters were pretreated at either 473 or 673 K in H{sub 2} after which their chemisorption behavior and catalytic properties for CO hydrogenation were determined. The iron remained well-dispersed at all times except after high temperature reduction when potassium was present. The single promotion by either Mn or K increased the olefin/paraffin ratio, and the doubly promoted catalyst gave very high selectivity to light olefins. Integral CO heats of adsorption at 300 K were measured, and they increased from 15 kcal/mole on the Fe/C catalysts to nearly 17 kcal/mole on each singly promoted sample to 21 kcal/mole on the doubly promoted catalyst. A model for the decomposition of these carbonyl clusters is proposed based on these results combined with previous studies utilizing Moessbauer effect spectroscopy, transmission election microscopy/energy dispersive spectroscopy, and diffuse reflectance Fourier transform infrared spectroscopy. The state of the MnO{sub x} and K phases on the iron surface, as well as Fe crystallite size, appears to play a dominant role in determining catalytic behavior.

• OSTI ID: 7089986
• Journal Information: Journal of Catalysis; (USA), Journal Name: Journal of Catalysis; (USA) Vol. 119:2; ISSN 0021-9517; ISSN JCTLA
• Country of Publication: United States
• Language: English

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