Mechanism of the Isomerization of 1-Alkene during Iron-Catalyzed Fischer–Tropsch Synthesis

Linear α-olefin production with Na-promoted Fe–Zn catalysts via Fischer–Tropsch synthesis

“…This transformation can proceed through the half-hydrogenated corresponding intermediate based on isotope experiments using the K-promoted Fe-Si catalyst reported by Shi et al 56 They suggested that the metal-adsorbed hydrogen species play an important role in isomerization based on the metal-hydrogen atom addition-elimination mechanism. 56 Noumi et al investigated the isomerization of 1-butene and found that solid bases (i.e., sodium oxide and potassium oxide) were also active in the production of 2-butenes, and that the stereoselectivity was highly dependent on the reaction temperature. 57 Then, the internal olens underwent skeletal isomerization to form branched olens.…”

Formation of 2-alkenes as secondary products during Fischer–Tropsch synthesis

“…3) suggests that, similar to the branched hydrocarbons, the internal alkenes should be the secondary products and formed through a pathway that differs from that results in 1-alkenes. The 1-octened 16 and 1-pentene-d 5 co-feed experiments during iron or cobalt catalyzed FT reactions [14,24] showed that the deutero-1-alkenes were reduced to deuterated alkanes, and isomerized to trans-2-alkenes and cis-2-alkenes with approximately equal amounts of the two isomers [14]. These results indicated that the 2-alkenes could be produced from corresponding 1-alkenes.…”

“…Furthermore, there is no consensus at the present time whether some of the n-alkanes and 2-alkenes are formed on FT-sites or on sites where chain growth cannot take place. We have shown that the deuterated octene can be converted to deuterated trans-2-octene, cis-2-octene and octane when octened 16 was used as the probe in an iron catalyzed FT reaction [14]. This experiment clearly showed that it is possible that 1-alkenes can be isomerized to 2-alkenes under FT reaction conditions.…”

Deuterium Exchange Study for Hydrogenation of D5-1-Pentene (4,4,5,5,5) Over Conventional Cobalt Fischer–Tropsch Catalyst

“…Miller and Moskovits [15] reported that deuterium from deuterated ethylene (CD 2 =CD 2 ) was incorporated in the hydrocarbon products without any H/D scrambling either as CD 2 or C 2 D 4 using an iron catalyst at 603 K and 0.69 MPa. Shi et al [19] concluded that there is no measurable H/D exchange in octane under iron-catalyzed FT reaction conditions where CO conversion is not complete. The authors further showed that H/D exchange does occur in alkenes but even here it is limited to the vinyl positions.…”