104. Changes in microstructure of a reduced cobalt catalyst during performing FT synthesis determined by in situ high-pressure syngas adsorption

抄録

Syngas adsorptions at 1.2MPa and room temperature on a precipitated cobalt catalyst reduced by H_2 and on that used for high-pressure FT synthesis were studied by diffuse reflectance FTIR spectroscopy. The syngas adsorption on the freshly reduced sample gives rise to two weak bands at 2013 and 2033cm^<-1>, which are assigned to linear adsorption of CO on fine metallic cobalt particles. Syngas adsorption on the sample used for FT synthesis gives rise to two strong bands at 1999 and 2021cm^<-1>, and several weak bands at 2150, 2025, 1897 and 1822cm^<-1>. The bands at 1999, 2021 and 1897cm^<-1> are assigned to CO adsorption on cobalt carbides; the bands at 2025 and 1822cm^<-1> may be associated with sintered metallic cobalt species and the band at 2150cm^<-1> due to Co^<2+> species.