Effect of mesoporous ZSM-5 morphology on the catalytic performance of cobalt catalyst for Fischer-Tropsch synthesis

Cobalt‐based Nanoreactors in Combined Fischer‐Tropsch Synthesis and Hydroprocessing: Effects on Methane and CO2 Selectivity

“…A high methane selectivity for Co@HZSM5 at high temperature is frequently reported in literature, especially for Co/zeolites [69] . It is most probably caused by strong cobalt‐zeolite interactions, [43,67] which could result in the stabilization of low coordinated Co sites and therefore in a higher methane selectivity as proposed by Sartipi et al [67] . This observation was also confirmed by Wang et al., [43] who found the highest methane selectivity for the materials with the strongest cobalt‐support interaction.…”

“…It is most probably caused by strong cobalt‐zeolite interactions, [43,67] which could result in the stabilization of low coordinated Co sites and therefore in a higher methane selectivity as proposed by Sartipi et al [67] . This observation was also confirmed by Wang et al., [43] who found the highest methane selectivity for the materials with the strongest cobalt‐support interaction. Furthermore, hydrogenolysis of preferably heavier paraffins is taking place on group VIII metals like cobalt, which causes successive demethylation at the end of the hydrocarbon chain, forming methane and a heavier fragment [41,42] .…”

“…Additionally, smaller cobalt particles are reported to support the formation of short‐chain hydrocarbons and hence promote methane formation [38,39] . Other factors can also contribute to a high methane selectivity like the existence of weak CO adsorption sites, [40] the hydrogenolysis of preferably heavier paraffins, which causes the successive demethylation forming methane and a heavier fragment, [41,42] as well as cobalt support interactions [43] . Several of these effects may be superimposed and therefore the specific cause of high methane selectivity is still a matter of debate.…”

Hierarchical ZSM-5 Supported CoMn Catalyst for the Production of Middle Distillate from Syngas

“…The effect of mesopores on FTS performance over ZSM-5 supported cobalt catalysts was also investigated by Wang and coworkers. 21 They synthesized mesoporous ZSM-5 catalysts with various morphologies, and the higher C 5 −C 11 selectivity was obtained over the catalyst with the lower mesopore volume of zeolite support, which could cause the increment in diffusion limitation. Besides the structure, the acidity especially Brønsted acid sites on hierarchical ZSM-5 also impact the product distribution.…”

Effects of SiO2/Al2O3 Ratio in ZSM-5 Zeolite on the Activity and Selectivity of a Bifunctional Cobalt Catalyst for Synthesis of Low-Pour-Point Diesel Fuels from CO and H2

“…The catalyst (generally based on zeolites or zeolite-like structures) ensures effective contact and interaction of the FT metal sites with the acid sites of HC cracking and isomerization [13][14][15][16][17][18][19][20]. The synthesis selectivity largely depends on the balance between the probability of chain growth and the HC cracking level [14,21,22], as well as on the properties of the catalyst components. For zeolite components of the catalysts, the selectivity-decisive factors are the chemical composition, crystal structure, pore structure, and surface acidity [23][24][25][26][27][28][29][30].…”