CO-insertion mechanism based kinetic model of the Fischer–Tropsch synthesis reaction over Re-promoted Co catalyst

A Single-Event MicroKinetic model for the cobalt catalyzed Fischer-Tropsch Synthesis

“…The activation energy for the metal alkenes formation is much closer to the value reported by Azadi et al [15] for the higher alkenes (n>3). Other kinetic modeling studies typically report a reverse order for the activation energies, i.e., the activation energy for the reductive elimination of metal alkyl species is lower than the activation energy to go from a metal alkyl to the corresponding alkene in the gas phase [22][23][24][25][26]. This is related to the reaction mechanism considered for the simulation of the alkanes and alkenes formation.…”

“…The ratio of alkenes to alkanes at higher carbon numbers exhibits a maximum at C4 at the experimental conditions shown in Figure 2. Typically a maximum in the alkenes to alkanes ratio is observed at C3 at FTS conditions [22,23,81] . This is probably attributable to H2/CO molar inlet ratio which is equal to 10 for the selectivities reported in Figure 2.…”

“…[23]. Ab initio calculated values for the CO chemisorption vary between 181.0 kJ mol -1 to 75.0 kJ mol -1 depending on the CO coverage [57].…”

“…There is a general consensus that the reaction proceeds through a polymerization-like scheme where the monomeric building block is formed on the catalyst surface and is inserted in a growing chain [1]. This has led to the development of various microkinetic models for Co catalyzed FTS [15][16][17][18][19][20][21][22][23][24][25][26]. Klinke et al [16] developed a microkinetic model based on direct CO dissociation and chain growth by inserting CHx species.…”

“…The latter aspect has been addressed by Todic et al [22,23] in two consecutive papers and by Bhatelia et al [24]. In these three papers the alkene desorption energy was considered to be chain length dependent, based on the idea of Botes [31].…”