Abstract
Hydrogenation of CO over silica and alumina supported cobalt catalysts has been investigated by the use of different experimental techniques; temperatures programmed reduction, in situ infrared spectroscopy, gravimetry and measurements of activity and selectivity. Temperature Programmed Reduction (TPR) was used to characterize uncalcined silica and alumina supported cobalt catalysts with different metal loading, 0.82% and 4.7% Co/SiO{sub 2} together with 1% and 4.6% Co/{gamma}-Al{sub 2}O{sub 3}. In addition to reduction peaks attributed to the reductive decomposition of cobalt nitrate (the metal precursor), TPR-profiles of all the catalysts except 1% Co/{gamma}-Al{sub 2}O{sub 3} featured peaks which have been assigned to the reduction of cobalt oxide, Co{sub 3}O{sub 4}. The lack of the cobalt oxide reduction peak for 1% Co/{gamma}-Al{sub 2}O{sub 3} has been interpreted as being a result of cobalt located in interstices of the alumina lattice, forming a cobalt aluminate spinel phase. The total extent of reduction of the catalysts increased with increasing cobalt loading. A higher degree of reduction for the silica supported catalysts compared to the alumina supported cobalt catalysts was found. CO hydrogenation on silica supported cobalt catalysts studied by in situ infrared spectroscopy revealed absorption bands characteristic of linearly absorbed CO on metallic cobalt. The constant
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Citation Formats
Fredriksen, G R.
Hydrogenation of CO on supported cobalt catalysts studied by in situ Fourier transform infrared (FTIR) spectroscopy.
Norway: N. p.,
1993.
Web.
Fredriksen, G R.
Hydrogenation of CO on supported cobalt catalysts studied by in situ Fourier transform infrared (FTIR) spectroscopy.
Norway.
Fredriksen, G R.
1993.
"Hydrogenation of CO on supported cobalt catalysts studied by in situ Fourier transform infrared (FTIR) spectroscopy."
Norway.
@misc{etde_10105913,
title = {Hydrogenation of CO on supported cobalt catalysts studied by in situ Fourier transform infrared (FTIR) spectroscopy}
author = {Fredriksen, G R}
abstractNote = {Hydrogenation of CO over silica and alumina supported cobalt catalysts has been investigated by the use of different experimental techniques; temperatures programmed reduction, in situ infrared spectroscopy, gravimetry and measurements of activity and selectivity. Temperature Programmed Reduction (TPR) was used to characterize uncalcined silica and alumina supported cobalt catalysts with different metal loading, 0.82% and 4.7% Co/SiO{sub 2} together with 1% and 4.6% Co/{gamma}-Al{sub 2}O{sub 3}. In addition to reduction peaks attributed to the reductive decomposition of cobalt nitrate (the metal precursor), TPR-profiles of all the catalysts except 1% Co/{gamma}-Al{sub 2}O{sub 3} featured peaks which have been assigned to the reduction of cobalt oxide, Co{sub 3}O{sub 4}. The lack of the cobalt oxide reduction peak for 1% Co/{gamma}-Al{sub 2}O{sub 3} has been interpreted as being a result of cobalt located in interstices of the alumina lattice, forming a cobalt aluminate spinel phase. The total extent of reduction of the catalysts increased with increasing cobalt loading. A higher degree of reduction for the silica supported catalysts compared to the alumina supported cobalt catalysts was found. CO hydrogenation on silica supported cobalt catalysts studied by in situ infrared spectroscopy revealed absorption bands characteristic of linearly absorbed CO on metallic cobalt. The constant frequency (2068 {+-} 4 cm{sup -1}) of this band at different reaction conditions (H{sub 2}/CO=2), P{sub Tot}=2.5, 6 or 11 bar, T=473K has been discussed in terms of a high local coverage of adsorbed CO. CO hydrogenation over 1% Co/{gamma}-Al{sub 2}O{sub 3} did not reveal absorption bands attributable to molecularly absorbed CO. Ultraviolet-visible spectroscopy (UV-VIS) diffuse reflectance and TPR-measurements indicated that cobalt was located in the alumina lattice, occupying tetrahedral lattice sites, hence being inaccessible for adsorption of CO. 237 refs., 107 figs., 26 tabs.}
place = {Norway}
year = {1993}
month = {Dec}
}
title = {Hydrogenation of CO on supported cobalt catalysts studied by in situ Fourier transform infrared (FTIR) spectroscopy}
author = {Fredriksen, G R}
abstractNote = {Hydrogenation of CO over silica and alumina supported cobalt catalysts has been investigated by the use of different experimental techniques; temperatures programmed reduction, in situ infrared spectroscopy, gravimetry and measurements of activity and selectivity. Temperature Programmed Reduction (TPR) was used to characterize uncalcined silica and alumina supported cobalt catalysts with different metal loading, 0.82% and 4.7% Co/SiO{sub 2} together with 1% and 4.6% Co/{gamma}-Al{sub 2}O{sub 3}. In addition to reduction peaks attributed to the reductive decomposition of cobalt nitrate (the metal precursor), TPR-profiles of all the catalysts except 1% Co/{gamma}-Al{sub 2}O{sub 3} featured peaks which have been assigned to the reduction of cobalt oxide, Co{sub 3}O{sub 4}. The lack of the cobalt oxide reduction peak for 1% Co/{gamma}-Al{sub 2}O{sub 3} has been interpreted as being a result of cobalt located in interstices of the alumina lattice, forming a cobalt aluminate spinel phase. The total extent of reduction of the catalysts increased with increasing cobalt loading. A higher degree of reduction for the silica supported catalysts compared to the alumina supported cobalt catalysts was found. CO hydrogenation on silica supported cobalt catalysts studied by in situ infrared spectroscopy revealed absorption bands characteristic of linearly absorbed CO on metallic cobalt. The constant frequency (2068 {+-} 4 cm{sup -1}) of this band at different reaction conditions (H{sub 2}/CO=2), P{sub Tot}=2.5, 6 or 11 bar, T=473K has been discussed in terms of a high local coverage of adsorbed CO. CO hydrogenation over 1% Co/{gamma}-Al{sub 2}O{sub 3} did not reveal absorption bands attributable to molecularly absorbed CO. Ultraviolet-visible spectroscopy (UV-VIS) diffuse reflectance and TPR-measurements indicated that cobalt was located in the alumina lattice, occupying tetrahedral lattice sites, hence being inaccessible for adsorption of CO. 237 refs., 107 figs., 26 tabs.}
place = {Norway}
year = {1993}
month = {Dec}
}