Abstract
Carbon-supported Fe, FeMn, and KFeMn catalysts derived from stoichiometric mixedmetal carbonyl clusters were pretreated at either 473 or 673 K in H 2 after which their chemisorption behavior and catalytic properties for CO hydrogenation were determined. The iron remained welldispersed 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 Mössbauer effect spectroscopy, transmission election microscopy/energy dispersive spectroscopy, and diffuse reflectance Fourier transform infrared spectroscopy. The state of the MnO x , and K phases on the iron surface, as well as Fe crystallite size, appears to play a dominant role in determining catalytic behavior.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
