Bimetallic Co-Fe nanocrystals deposited on SBA-15 and HMS mesoporous silicas as catalysts for Fischer–Tropsch synthesis
Fischer–Tropsch synthesis (493 K, 0.62 MPa CO, 1.24 MPa H2) has been performed over monometallic and bimetallic Co and/or Fe clusters deposited on mesoporous silicas (HMS and SBA-15). Catalysts have been prepared by incipient wetness impregnation and characterized by N2 adsorption–desorption isotherms, X-ray diffraction (XRD), H2-temperature programmed reduction (H2-TPR), and transmission electron microscopy (TEM).HMS supported Co-Fe catalyst showed the highest activity and C5+ hydrocarbon selectivity, while Co-Fe/SBA-15 catalyst revealed the highest selectivity to alcohols. Both bimetallic catalysts were more active toward the C2–C4 hydrocarbon fraction, with an enhancement in the selectivity to C2, C3 and 1-C4 olefins. Both bimetallic catalysts showed greater chain growth probability values than the monometallic iron based catalysts although their performance in catalytic tests were more close to the iron catalyst.
Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (76 K)Download as PowerPoint slideHighlights► Bimetallic catalysts Co-Fe/HMS and Co-Fe/SBA-15 were used for Fischer–Tropsch synthesis. ► They promoted a high alcohols formation, being ethanol the main oxygenated product. ► Among the olefins both Co-Fe catalysts were more selective toward the propylene. ► The Co-Fe/HMS showed higher selectivity to C5+ and alcohols than Fe/HMS catalyst. ► The Co-Fe/SBA-15 exhibited a higher selectivity to C2–C4 hydrocarbons than Fe/SBA-15.
Journal: Applied Catalysis A: General - Volumes 423–424, 7 May 2012, Pages 146–153