Sammendrag
A cobalt based Fischer–Tropsch synthesis (FTS) catalyst, supported on a carbon nanofibers/carbon felt
composite (Co/CNF/CF) was studied in situ at realistic conditions. The catalyst was monitored by Xray
absorption spectroscopy (XAS), high-resolution X-ray powder diffraction (HR-XRPD) and Raman
spectroscopy, while changes in the gas phase were observed by mass spectrometry (MS). Transmission
electron microscopy (TEM) was also applied to characterise the catalyst. The catalyst has a bimodal particle
size distribution and exhibits a high deactivation rate. During the in situ study the catalyst appears to
reduce further at the induction period of FTS, while crystallite growth is been detected in the same period.
At steady state FTS the amount of metallic Co is constant. A change in the volumetric flow towards higher
conversions did not affect the degree of reduction or the crystallite size of the catalyst. Post-treatment
at 400 ◦C under H2 atmosphere leads to sintering of the cobalt particles, while a CO treatment followed
by H2 treatment creates a catalyst rich in hexagonal close packed cobalt through the formation of a Co2C
intermediate
composite (Co/CNF/CF) was studied in situ at realistic conditions. The catalyst was monitored by Xray
absorption spectroscopy (XAS), high-resolution X-ray powder diffraction (HR-XRPD) and Raman
spectroscopy, while changes in the gas phase were observed by mass spectrometry (MS). Transmission
electron microscopy (TEM) was also applied to characterise the catalyst. The catalyst has a bimodal particle
size distribution and exhibits a high deactivation rate. During the in situ study the catalyst appears to
reduce further at the induction period of FTS, while crystallite growth is been detected in the same period.
At steady state FTS the amount of metallic Co is constant. A change in the volumetric flow towards higher
conversions did not affect the degree of reduction or the crystallite size of the catalyst. Post-treatment
at 400 ◦C under H2 atmosphere leads to sintering of the cobalt particles, while a CO treatment followed
by H2 treatment creates a catalyst rich in hexagonal close packed cobalt through the formation of a Co2C
intermediate