The effect of promoters on reduction of Ru/ZrO2/Co/SiO2 catalyst for Fischer-Tropsch synthesis as studied by in situ XANES.

P. Kangvansura, Y. Poo-arporn, H. Schulz, A. Worayingyong
Kasetsart University, TH

Keywords: cobalt, Fischer-Tropsch, XANES

Summary:

Abstract Ru/ZrO2/Co/SiO2 was prepared via a co-precipitation and an incipient wetness impregnation methods and characterized by XRD and XANES. To study the effect of promoters on reduction of active cobalt species on the catalyst, Ru/ZrO2/Co/SiO2, ZrO2/Co/SiO2, Ru/Co/SiO2, and Co/SiO2 were observed by in situ XANES. The results showed no Co(0) on Co/SiO2 whereas Ru/Co/SiO2 was reduced to 37.5% Co(0). ZrO2 exhibited less effect on the reduction of Co species. Ru/ZrO2/Co/SiO2 diluted with quartz as the same composition ratio in the synthetic reaction was investigated producing 34.9% Co(0) and 65.1% CoO after reduction. Fischer-Tropsch product selectivity from the reaction over Ru/ZrO2/Co/SiO2 catalyst was observed in terms of chain growth probabilities of n-paraffins as a function of carbon numbers and as a function of time during self-organization of the catalyst. The growth probability showed that paraffins with high carbon number were high at 72 h indicating the steady state of Fischer-Tropsch reaction.