Fischer-Tropsch Synthesis Activity Research Articles

Facet sensitivity of iron carbides in Fischer-Tropsch synthesis

Fischer-Tropsch synthesis (FTS) is a structure-sensitive reaction of which performance is strongly related to the active phase, particle size, and exposed facets. Compared with the full-pledged investigation on the active phase and particle size, the facet effect has been limited to theoretical studies or single-crystal surfaces, lacking experimental reports of practical catalysts, especially for Fe-based catalysts. Herein, we demonstrate the facet sensitivity of iron carbides in FTS. As the prerequisite, {202} and {112} facets of χ-Fe5C2 are fabricated as the outer shell through the conformal reconstruction of Fe3O4 nanocubes and octahedra, as the inner cores, respectively. During FTS, the activity and stability are highly sensitive to the exposed facet of iron carbides, whereas the facet sensitivity is not prominent for the chain growth. According to mechanistic studies, {202} χ-Fe5C2 surfaces follow hydrogen-assisted CO dissociation which lowers the activation energy compared with the direct CO dissociation over {112} surfaces, affording the high FTS activity.

Study fischer-tropsch synthesis

This work was to evaluate the catalytic properties Ru/Cobalt/SBA-15 catalyst for Fischer-Tropsch synthesis (FTS). The molecular sieve SBA-15 synthesized by hydrothermal method with rice husk ashes (RHA) and with tetraethyl orthosilicate (TEOS). The Ru promoted Co/SBA-15 catalyst was prepared by wet impregnation method and was characterized by X-ray diffraction, X-ray energy dispersion spectrophotometer, N2 adsorption-desorption, temperature-programmed reduction and transmission electron microscopy. The Fischer-Tropsch synthesis using the catalysts were carried out to evaluate the catalysts activities and its effect on FTS product distribution. The synthesis was carried out in a slurry reactor operating at 513 K, 20 atm, CO : H2 molar ratio of 1 : 2. X-ray diffraction showed that the calcined cobalt catalyst did not modify the structure of SBA-15, proving that Co was present under the form of Co3O4 in the catalyst. The addition of cobalt in SBA-15 decreased the specific superficial area of the molecular sieve. By RTP results was found the ranges of temperature reduction typical of iron oxides phases. Fischer-Tropsch synthesis activity and C5+hydrocarbon selectivity increased with the addition of Ru. The increases in activity and selectivity were attributed to the increased number of active sites resulting from higher reducibility and the synergetic effect of Ru and Co. The most interesting fact to be pointed out is that the use of this catalytic system for the catalyst prepared with alternative source of silica and cheap (rice hull ash) showed high selectivity in liquid products, that is, in hydrocarbons with C5+ (88.2% w/w ), higher than the catalyst prepared with conventional silica source.

Application fischer-tropsch synthesis: a review

This work was to evaluate the catalytic properties Ru/Cobalt/SBA-15 catalyst for Fischer-Tropsch synthesis (FTS). The molecular sieve SBA-15 synthesized by hydrothermal method with rice husk ashes (RHA) and with tetraethyl orthosilicate (TEOS). The Ru promoted Co/SBA-15 catalyst was prepared by wet impregnation method and was characterized by X-ray diffraction, X-ray energy dispersion spectrophotometer, N2 adsorption-desorption, temperature-programmed reduction and transmission electron microscopy. The Fischer-Tropsch synthesis using the catalysts were carried out to evaluate the catalysts activities and its effect on FTS product distribution. The synthesis was carried out in a slurry reactor operating at 513 K, 20 atm, CO : H2 molar ratio of 1 : 2. X-ray diffraction showed that the calcined cobalt catalyst did not modify the structure of SBA-15, proving that Co was present under the form of Co3O4 in the catalyst. The addition of cobalt in SBA-15 decreased the specific superficial area of the molecular sieve. By RTP results was found the ranges of temperature reduction typical of iron oxides phases. Fischer-Tropsch synthesis activity and C5+hydrocarbon selectivity increased with the addition of Ru. The increases in activity and selectivity were attributed to the increased number of active sites resulting from higher reducibility and the synergetic effect of Ru and Co. The most interesting fact to be pointed out is that the use of this catalytic system for the catalyst prepared with alternative source of silica and cheap (rice hull ash) showed high selectivity in liquid products, that is, in hydrocarbons with C5+ (88.2% w/w), higher than the catalyst prepared with conventional silica source.

Enhanced Fischer–Tropsch synthesis performance on MOFs‐derived Fe‐based catalysts constrained by SiO2

Fischer–Tropsch synthesis (FTS) is an essential technology to produce clean fuel, and catalyst will affect syngas conversion efficiency and product distribution. For traditional oxides‐supported catalysts, the mutual constraint between active metal loading and dispersion at high metal loading is hard to overcome, which will hinder the synthesis of high‐performance FTS catalysts. Herein, we report an efficient method for synthesizing iron‐based catalysts with not only high loading but also high dispersion. By using metal–organic frameworks Fe‐MIL‐88B as the precursor, we synthesized a series of Fe@C@SiO2 catalysts by tuning the amount of tetraethyl orthosilicate (TEOS) through a one‐step method; TEOS was in situ introduced and followed by high‐temperature carbonization. The prepared catalyst possesses a Fe@C core–shell structure with carbon layer encapsulation. Meanwhile, the SiO2 in the catalyst can effectively confine iron particles and avoid the agglomeration of iron species during high‐temperature carbonization. Among these catalysts, the Fe@C@SiO2‐0.005 showed the greatest FTS performance because high iron dispersion was achieved at high iron loading. Further increase SiO2 content enhanced the confinement effect of SiO2 but generated inert Fe2SiO4 species, which decreased the adsorption and activation of reactants and FTS activity.

Reactive Separations of CO/CO2 mixtures over Ru–Co Single Atom Alloys

Reactive separations of CO/CO2 mixtures are a promising pathway to lower the energy requirement of CO2 hydrogenation to chemicals and fuels, with applications in the U.S. Navy’s seawater-to-fuel process. With the CO/CO2 feedstock, a challenge is activating CO to produce heavier hydrocarbons while preventing CO2 methanation, requiring low-temperature Fischer-Tropsch synthesis (FTS) catalysts. In this work, we demonstrate that a Ru–Co single atom alloy (SAA) catalyst produces C5+ hydrocarbons at a rate of 11.7 μmol/s/g-cobalt (hexane basis) in a 50/50 CO/CO2 stream with ≤1% CO2 conversion. The reaction operates at a relatively low temperature (200 °C) and high gas hourly space velocity (GHSV: 84,000 mL/g/h) that is compatible with the upstream reverse water-gas shift reaction. Detailed experiments, catalyst characterizations, and density functional theory (DFT) calculations have been conducted to understand the active phase, the role of the Ru dopant, and catalyst restructuring that occurs at elevated temperatures (>200 °C). Ru dopants are found to promote the reduction of Co species, enabling catalytic activity for CO hydrogenation without pre-reduction, but may not enhance the FTS activity or desired C5+ hydrocarbon selectivity.

Effect of sodium incorporation into Fe-Zn catalyst for Fischer- Tropsch synthesis to light olefins

The effects of precipitant and solid basicity on the Fischer-Tropsch Synthesis (FTS) activity of the sodium doped zinc ferrite catalysts were investigated. Olefin selectivity and stability of the catalysts were interrelated with the solid basicity which varied with the type of the precipitant, the amount of alkali promoter and its incorporation way into the catalyst matrix. The type of the precipitant and ionic medium of hydrolysis were seen to affect the textural properties of zinc ferrites. A cubic spinel phase of ZnFe2O4 were observed for all catalysts. Sodium promoter significantly modified the reduction behavior of the samples as well. Since the ionic strength was believed to have an effect on the solubility constants of Fe(OH)3 and Zn(OH)2, the purity of ZnFe2O4 nanoparticles would be expected to change as to be noticed from their different TPR profiles. All zinc ferrite samples had a much smaller crystal size than the precipitated iron, showing the structural promoter effect of zinc. In the study, the basicity of the catalysts was also correlated with FTS activity. All alkali promoted zinc ferrite catalysts have shown high olefin selectivity of about 50%. Although a basicity of certain extent is a must to attain high olefin selectivity, coking seems inevitable at high basicity. Therefore, an optimum interaction strength of the surface for CO dissociation appeared to exist and it might be tuned by surface basicity.

Theoretical study of CO adsorption and activation on h-Fe7C3[formula omitted] for Fischer-Tropsch synthesis

The h-Fe7C3 phase of iron carbide catalysts have been gained wide attentions for the impressive intrinsic activity in typical medium-temperature Fischer-Tropsch synthesis (FTS). In this study, the adsorption and activation of CO on h-Fe7C3(11¯1) surface were studied by density functional theory (DFT) calculations to understand the FTS mechanism. Calculated results showed that the B5 site on h-Fe7C3(11¯1) surface demonstrates excellent intrinsic activity for CO adsorption and activation. The route CO+H—HCO—CH+O—CH2+O is identified as a preferred CO activation pathway on the B5 site for h-Fe7C3(11¯1) surface with the effective energy barrier of 1.380 eV. Furthermore, the FTS reaction mechanism with the surface carbon atoms involved was explored preliminarily, which confirms that the surface carbons can undergo hydrogenation reaction to produce the CH species feasibly, and meanwhile, the carbon vacant sites are generated. Subsequently, the influences of carbon vacancy on the CO adsorption and activation on (11¯1) were studied. It was observed that the vacancy surface is more conducive to the elementary reactions of CO adsorbed on the B5 site. In particular, CO can be easily dissociated on the VC2 surface with energy barrier of 0.77 eV.

Direct Construction of K-Fe3C@C Nanohybrids Utilizing Waste Biomass of Pomelo Peel as High-Performance Fischer–Tropsch Catalysts

As the only renewable organic carbon source, abundant biomass has long been established and developed to mass-produce functionalized carbon materials. Herein, an extremely facile and green strategy was executed for the first time to in situ construct K-Fe3C@C nanohybrids directly by one-pot carbonizing the pomelo peel impregnated with Fe(NO3)3 solutions. The pyrolytically self-assembled nanohybrids were successfully applied in Fischer–Tropsch synthesis (FTS) and demonstrated high catalytic performance. Accordingly, the optimized K-Fe3C@C catalysts revealed excellent FTS activity (92.6% CO conversion) with highlighted C5+ hydrocarbon selectivity of 61.3% and light olefin (C2-4=) selectivity of 26.0% (olefin/paraffin (O/P) ratio of 6.2). Characterization results further manifest that the high performance was correlated with the in situ formation of the core-shell nanostructure consisting of Fe3C nanoparticles enwrapped by graphitized carbon shells and the intrinsic potassium promoter originated in pomelo peel during high-temperature carbonization. This work provided a facile approach for the low-cost mass-fabrication of high-performance FTS catalysts directly utilizing waste biomass without any chemical pre-treatment or purification.

A high active sites exposed hollow Co@SiO2 nanoreactor for high performance fischer–tropsch synthesis

Optimizing catalyst geometry to break current limitations of Fischer-Tropsch synthesis (FTS) activity and the selectivity of long-chain hydrocarbons is a promising and challenging subject. Herein, a hollow Co@SiO2 catalyst with high dispersion of cobalt species anchored inside mesoporous hollow silica shell was successfully synthesized with the help of Co-metal organic framework materials, which displayed a surprisingly high C5+ hydrocarbons selectivity of 93.3% with a low methane selectivity of 3.4% at a remarkable high activity (CTY = 5.1 × 10-5 molCO gCo-1 s−1). The catalyst remained excellent stability for 200 h under industrially relevant conditions. The hollow core–shell structure provided an internal cavity environment that shortened the diffusion distance and contact area between Co metal and support, and improved exposed active cobalt sites and residence time of intermediates, inducing the growth of the catalytic activity and long-chain hydrocarbons selectivity. Protection of silica shell prevented the aggregation of active cobalt nanoparticles, further promoting the catalyst stability. This work provides a new insight into the design of high efficient and stable catalysts for FTS reaction.

In Situ Active Site for Fe-Catalyzed Fischer-Tropsch Synthesis: Recent Progress and Future Challenges.

Fischer-Tropsch synthesis (FTS) that converts syngas into long-chain hydrocarbons is a key technology in the chemical industry. As one of the best catalysts for FTS, the Fe-based composite develops rich solid phases (metal, oxides, and carbides) in the catalytic reaction, which triggered the quest for the true active site in catalysis in the past century. Recent years have seen great advances in probing the active-site structure using modern experimental and theoretical tools. This Perspective serves to highlight these latest achievements, focusing on the geometrical structure and thermodynamic stability of Fe carbide bulk phases, the exposed surfaces, and their relationship to FTS activity. The current reaction mechanisms on CO activation and carbon chain growth are also discussed, in the context of theoretical models and experimental evidence. We also present the outlook regarding the current challenges in Fe-based FTS.

Modulating Fischer-Tropsch synthesis performance on the Co3O4@SixAly catalysts by tuning metal-support interaction and acidity

ZIF-67 derived catalysts for Fischer-Tropsch synthesis have attracted much attention in recent years, while there is still a potential to improve their activity and selectivity. In this work, we prepared Si/Al co-immobilized Co 3 O 4 @Si x Al y catalysts by in-situ doping tetraethylorthosilicate and aluminum nitrate during the synthesis of ZIF-67. The effects of different Si/Al ratios on the metal-support interaction, acidity and FTS performance were explored. Results indicated that the Co 3 O 4 @Si 0 Al 4 catalyst exhibited the best FTS performance with the CO conversion as high as 79.9% and CTY (cobalt time yield) value of 19.5 × 10 −5 mol CO ·g Co −1 ·s −1 , which was ascribed to the moderate metal-support interaction and the most active Co sites. Meanwhile, the Co 3 O 4 @Si 3 Al 1 and Co 3 O 4 @Si 2 Al 2 catalysts exhibited higher iso-paraffin and olefin selectivity due to more acidic sites. The Co 3 O 4 @Si 0 Al 4 catalyst exhibited the highest FTS activity due to the moderate metal-support interaction (MSI), while the Co 3 O 4 @Si 3 Al 1 and Co 3 O 4 @Si 2 Al 2 catalysts showed certain hydrocracking and isomerization ability due to the formation of acidic sites. • Co 3 O 4 @Si x Al y catalysts were prepared by in-situ doping method based on ZIF-67. • The Co 3 O 4 @Si 0 Al 4 exhibited the highest Fischer-Tropsch synthesis (FTS) activity. • The high activity was due to moderate metal-support interaction and most active sites. • Acidic sites promoted the hydrocracking and isomerization of long chain hydrocarbons.

Pretreating Co/SiO2 to generate highly active Fischer-Tropsch synthesis catalyst with low CH4 selectivity

The effects of pretreatment methods (DR, R, ROR) on the microstructure of Co/SiO2 catalysts and the activity for Fischer-Tropsch synthesis (FTS) were investigated. The pretreated catalysts were characterized by TEM, HRTEM, XRD, XPS, H2-TPD, TG and TPR. The results showed that after the pretreatments, specific morphological of the Co species changed, forming new Co active surface species. The Co particles redispersed and the Co species was facile to be re-reduced. The Co/SiO2 catalysts pretreated by different method showed different catalytic performance. The catalyst treated by the reduction-passivation had higher activity and C5+ selectivity for FTS.

Preparation of high performance Co3O4/Al2O3 catalysts by doping Al into ZIF-67: Effect of Al sources on Fischer-Tropsch synthesis

MOFs derived Co-based catalysts are a kind of potential Fischer-Tropsch synthesis (FTS) catalyst with superior cobalt dispersion and high cobalt loading, but they usually exhibit low activity and high CH4 selectivity. In this study, Al sources were introduced during the synthesis of ZIF-67 by in-situ doping method to obtain the high performance Co3O4/Al2O3-x catalysts. The effect of different Al sources including AlCl3·6H2O, Al(C3H7O)3 and Al(NO3)3·9H2O on the FTS performance of the Co3O4/Al2O3-x catalysts was investigated. Results indicated that the prepared Co3O4/Al2O3-x catalysts exhibited better FTS activity and lower CH4 selectivity than the Co@C catalyst obtained by direct carbonation of ZIF-67. The Co3O4/Al2O3-x catalysts with different Al sources showed different FTS performance. The Co3O4/Al2O3-III catalyst exhibited the highest FTS activity which was ascribed to its strongest metal-support interaction and the most active sites. Moreover, due to the different physical properties, the Co3O4/Al2O3-III catalyst showed higher gasoline selectivity while the Co3O4/Al2O3-II catalyst showed higher diesel selectivity.

Fischer–Tropsch Synthesis for Light Olefins from Syngas: A Review of Catalyst Development

Light olefins as one the most important building blocks in chemical industry can be produced via Fischer–Tropsch synthesis (FTS) from syngas. FT synthesis conducted at high temperature would lead to light paraffins, carbon dioxide, methane, and C5+ longer chain hydrocarbons. The present work focuses on providing a critical review on the light olefin production using Fischer–Tropsch synthesis. The effects of metals, promoters and supports as the most influential parameters on the catalytic performance of catalysts are discussed meticulously. Fe and Co as the main active metals in FT catalysts are investigated in terms of pore size, crystal size, and crystal phase for obtaining desirable light olefin selectivity. Larger pore size of Fe-based catalysts is suggested to increase olefin selectivity via suppressing 1-olefin readsorption and secondary reactions. Iron carbide as the most probable phase of Fe-based catalysts is proposed for light olefin generation via FTS. Smaller crystal size of Co active metal leads to higher olefin selectivity. Hexagonal close-packed (HCP) structure of Co has higher FTS activity than face-centered cubic (FCC) structure. Transition from Co to Co3C is mainly proposed for formation of light olefins over Co-based catalysts. Moreover, various catalysts’ deactivation routes are reviewed. Additionally, techno-economic assessment of FTS plants in terms of different costs including capital expenditure and minimum fuel selling price are presented based on the most recent literature. Finally, the potential for global environmental impacts associated with FTS plants including atmospheric and toxicological impacts is considered via lifecycle assessment (LCA).

Effect of Na, Cu and Ru on metal-organic framework-derived porous carbon supported iron catalyst for Fischer-Tropsch synthesis

• Fe was highly dispersed on MIL-100(Fe) derived porous carbon with a high loading (>37 wt%). • XRD and HRTEM show particle size decrease for Na, Cu, and Ru-promoted catalysts. • Cu-promoted catalysts show a high CO conversion and a stable FT activity. • Na addition increased O/P ratio and C 5+ selectivity in product distribution. • Ru-promoted catalysts show a deactivation at high reaction temperature (340 °C). Fischer-Tropsch synthesis (FTS) is studied over Metal-organic framework (MOF) based porous carbon supported iron catalysts promoted with Na, Cu and Ru metals. The FTS results showed that all promoters can enhance CO conversion, FT product yield (FTY), and CO 2 selectivity is also increased. Among all promoters, Cu-based sample exhibits the best promoting effect in activity (FTY=0.154 mol CO g Fe −1 h − 1 ). Interestingly, the activity is about 2 times higher to that of unpromoted catalysts. Ru-contained sample exhibits the most significant influence on the light hydrocarbon production, with the C 1–4 hydrocarbon selectivity above 70%. Na-contained sample performed the highest C 5+ selectivity of 66% with a medium CO conversion of 51%. The improved FTS activity and selectivity of promoted catalysts is related to the decrease in iron particle size as confirmed by X-ray diffraction (XRD), and transmission electron microscopy (TEM). It is confirmed, the small iron particles of the promoted catalyst are stabilized on the surface of carbon matrix, preventing further aggregation at high temperature, which is contributed to the improved FTS performance. Our research study showed that Na, Cu and Ru can not only affect the distribution of resulting products but also improve the activity of FTS. In short, the effect of Cu is remarkable on the MOF-derived catalyst. Similarly, the MOF-derived porous carbon catalysts confined the iron species during the reaction process, provide a clear structure-activity relationship between the promoters and the catalytic performance. Finally, this novel work can provide a new pathway for metal-organic framework-derived Fe-embedded porous carbon catalysts for Fischer-Tropsch synthesis.

Enhanced gasoline selectivity through Fischer-Tropsch synthesis on a bifunctional catalyst: Effects of active sites proximity and reaction temperature

Abstract The combination of Co-based catalysts and HZSM-5 has been reported to modify product distribution in Fischer-Tropsch synthesis (FTS) since the heavy hydrocarbons synthesized on Co0 could be hydrocracked to light hydrocarbons on HZSM-5. It has been accepted that the proximity between active Co0 sites and acidic sites as well as reaction temperature will significantly affect the product selectivity but no systematic report was found. In this paper, we designed two bifunctional catalysts to explore the effect of proximity and reaction temperature on FTS performance systematically. The tandem bifunctional catalyst Co/SZ-B possessed outstanding FTS activity and higher gasoline (C5-11) selectivity due to an appropriate proximity and metallic particle size. Reaction temperature was another sensitive impacting factor on FTS performance, especially on gasoline selectivity. With temperature increase, hydrocracking of heavy hydrocarbons on active Co0 sites and acidic sites all improved, which resulted in much increased formation of light hydrocarbons. The optimum reaction temperature for gasoline production was 270 °C due to the synergistic effect of active Co0 sites and acidic site. The finding about the effect of the active site proximity and reaction temperature on the FTS performance can provide a solid basis for rational design of bifunctional catalysts to modulate product distribution.

Effect of Changing Amounts of Promoters and Base Fe Metal in a Multicomponent Catalyst Supported on Coal-Based Activated Carbon for Fischer–Tropsch Synthesis

The effect of varying the amounts of metals Fe, Cu, K, and Mo was studied on a catalyst supported on activated carbon (AC), which is an item of novelty of this paper. The base-case catalyst contains 16% Fe, 0.9% K, 6% Mo, and 0.8% Cu relative to the AC support. For all of the catalysts used, alcohol production is small. The production of hydrocarbons depends upon the amount of Fe and other promoters used. The amount of Fe was increased from 0% to 32% on the catalyst containing base-case amounts of the other materials. While 0% Fe shows no activity towards Fischer–Tropsch synthesis (FTS), 32% Fe shows a marginal increase in FTS activity when compared with 16% Fe. Furthermore, the amount of K was increased from 0% to 1.8%, with the other metals in their base-case amounts. The selectivity of C1–C4 decreases with the addition of K, while the selectivity of C5+ increases. Analogously, the amount of Mo was increased from 0% to 12%. A small amount of Mo results in an increase in FTS activity but decreases with the addition of more Mo. Cu on the catalyst was increased from 0% to 1.6%, with 0.8% Cu proving optimum for FTS.

Ru1Con Single-Atom Alloy for Enhancing Fischer–Tropsch Synthesis

Fischer–Tropsch synthesis (FTS) is a significant catalytic process for the production of liquid fuel and fine chemicals from natural gas-, coal-, and biomass-derived syngas. However, exploring high-performance catalysts and understanding the catalytic mechanism remain challenging. Herein, we design a Ru1Con single-atom alloy (SAA) catalyst with isolated Ru atoms anchored onto a Co nanoparticle surface through a two-dimensional confinement strategy to achieve greatly improved FTS activity (2.6 molCO molM–1 h–1) and long-chain hydrocarbon selectivity (C5+: 86.0%) at a low reaction temperature of 150 °C. A series of in situ experiments, catalytic tests, and density functional theory (DFT) calculations reveal that the Ru single-atom sites in Ru1Con SAA are more active for the FTS reaction than pure Ru and Co surfaces. This is because single-atom Ru with a much higher electronic density near the Fermi level could effectively and simultaneously decrease the rate-limiting barriers of both C–O splitting and chain growth processes. This work demonstrates the possibility of designing Ru single-atom sites to improve FTS performance and provides a deeper understanding of the strategy for developing other high-performance industrial catalysts.

Cobalt-based Fischer-Tropsch synthesis: Effect of the catalyst granule thermal conductivity on the catalytic performance

A series of model Fischer-Tropsch synthesis (FTS) catalyst granules with different thermal conductivity were prepared to study the influence of catalyst granule thermal conductivity on FTS performance. A clear correlation was found between catalyst granule thermal conductivity and FTS activity, CH4 selectivity, C5+ selectivity, mole ratio of olefin to paraffin and branched hydrocarbon selectivity at high CO conversion. This could be due to that the overheating effect occurred within catalyst granule with low thermal conductivity. On the basis of the widely accepted ‘alkyl’ mechanism for FTS, the overheating effect was able to affect the adsorption of H2 and CO molecules, the hydrogenation of carbide species as well as chain growth. In addition, the overheating effect could lead to the catalyst structure reconstruction, sintering and deactivation.

Recent developments in catalyst pretreatment technologies for cobalt based Fisher–Tropsch synthesis

Abstract Stringent environmental regulations and energy insecurity necessitate the development of an integrated process to produce high-quality fuels from renewable resources and to reduce dependency on fossil fuels, in this case Fischer–Tropsch synthesis (FTS). The FT activity and selectivity are significantly influenced by the pretreatment of the catalyst. This article reviews traditional and developing processes for pretreatment of cobalt catalysts with reference to their application in FTS. The activation atmosphere, drying, calcination, reduction conditions and type of support are critical factors that govern the reducibility, dispersion and crystallite size of the active phase. Compared to traditional high temperature H2 activation, both hydrogenation–carbidisation–hydrogenation and reduction–oxidation–reduction pretreatment cycles result in improved metal dispersion and exhibit much higher FTS activity. Cobalt carbide (Co2C) formed by CO treatment has the potential to provide a simpler and more effective way of producing lower olefins, and higher alcohols directly from syngas. Syngas activation or direct synthesis of the metallic cobalt catalyst has the potential to remove the expensive H2 pretreatment procedure, and consequently simplify the pretreatment process, which would make it more economical and thus more attractive to industry.