Chemical Vapor Deposition of Ruthenium Nano Layer on Co/Al2O3 Catalyst for Fischer-Tropsch Synthesis Using Ru3(CO)12 Precursor

In present investigation, ruthenium was deposited on cobalt supported alumina catalyst by Chemical Vapor Deposition (CVD) of Ru3(CO)12 for Fischer-Tropsch Synthesis (FTS). The 15.0 wt% Co/γ-Al2O3 catalyst was prepared by wet impregnation of cobalt nitrate aqueous solution, and then dried and calcined at 400oC for 4 h. To optimize the CVD operating conditions in which Ru3(CO)12 starts to decompose on surface of the catalyst, the decomposition products of the CVD processwere passed through a gas cell of FT-IR. In a specific temperature range, ruthenium deposited selectively on the surface of cobalt active phase.The CVD of ruthenium onto Co/γ-Al2O3 catalyst increased the catalyst reducibility which in turnled to a higher CO hydrogenation activity in FTS process. Furthermore, the promoted cobalt catalyst showed a better selectivity towards heavy hydrocarbons than the reference unpromoted catalyst. The effects of temperature (210oC-240oC) and H2 /CO ratio (1-3) for all catalysts were examined. For the all operating conditions, the promoted catalyst performed much better than the unpromoted catalyst.