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  • 1
    Electronic Resource
    Electronic Resource
    Furfural hydrogenation over carbon‐supported copper (1999)
    Springer
    Catalysis letters 60 (1999), S. 51-57 
    Details
    ISSN: 1572-879X
    Keywords: furfural hydrogenation ; Cu/carbon catalysts ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Furfural hydrogenation over copper dispersed on three forms of carbon – activated carbon, diamond and graphitized fibers – were studied. Only hydrogenation of the C=O bond to form either furfuryl alcohol or 2‐methyl furan occurred at temperatures from 473 to 573 K. Reduction at 573 K gave the most active catalysts, all three catalysts had activation energies of 16 kcal/mol, and turnover frequencies were 0.018–0.032 s-1 based on the number of Cu0 + Cu+ sites, which were counted by N2O adsorption at 363 K and CO adsorption at 300 K, respectively. The Cu/activated carbon catalyst showed no deactivation during 10 h on stream, in contrast to the other two catalysts. A simple Langmuir–Hinshelwood model invoking two types of sites was able to fit all kinetic data quite satisfactorily, thus it was consistent with the presence of both Cu0 and Cu+ sites.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1019090520407
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    Olefin selective carbon-supported K-Fe-Mn CO hydrogenation catalysts: A kinetic, calorimetric, chemisorption, infrared and Mössbauer spectroscopic investigation (1990)
    Springer
    Catalysis letters 7 (1990), S. 219-240 
    Details
    ISSN: 1572-879X
    Keywords: Carbon supported Fe ; Fe-Mn ; K-Fe-Mn catalysts ; mixed metal carboxyl clusters ; chemisorption ; kinetic measurements ; calorimetric measurements ; infrared spectroscopy ; Mössbauer spectroscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Carbon-supported Fe, Fe-Mn, and K-Fe-Mn catalysts derived from stoichiometric mixed-metal carbonyl clusters were pretreated at either 473 K or 673 K in hydrogen. Chemisorption and kinetic measurements were conducted following these pretreatments. The iron remained highly dispersed at all times except after high temperature reductions when potassium was present. The single promotion by either Mn or K increases the olefin/paraffin ratio, while the doubly promoted catalyst gave very high selectivities for light olefins. Isothermal, integral heats of adsorption of CO were determined at 300 K, and they increased from 15 kcal/mole for Fe3/C to nearly 17 kcal/mole for both the singly promoted Fe2Mn/C and KFe3/C catalysts to 21 kcal/mole for the doubly promoted KFe2Mn/C sample. A model of the decomposition of these carbonyl clusters is proposed based on calorimetric, Mössbauer effect spectroscopic and diffuse reflectance Fourier transform infrared spectroscopic studies. The state of the MnOx and K phases on the iron surface, as well as the Fe crystallite size, appears to play a dominant role in determining the catalytic behavior.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00764505
    Library Location Call Number Volume/Issue/Year Availability
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    Paper (German National Licenses)
    Fulltext
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