Alumina-supported Cobalt Catalysts Research Articles

Dry synthesis of alumina-supported cobalt catalyst for highly enhanced catalytic oxidation

Alumina-supported cobalt oxide excels as an oxidation catalyst, however, strong metal-support interactions (SMSI) of cobalt and alumina can lead to inactive phases such as cobalt aluminate. To avoid the formation of the inactive phase, it was hypothesized that reducing the number of hydroxyl group anchoring sites on the alumina would enable a higher ratio of active cobalt oxide than inactive phases. We devised a dry synthesis method combined with alumina dehydroxylation and solid-state impregnation of cobalt. Characterization results including XRD, XPS, and Raman spectroscopy confirm the formation of the desired active phase on the dehydroxylated alumina. The resultant catalysts demonstrate a surprising decrease in the cobalt content (max. tenfold from 20 wt.% to 2 wt.% of cobalt loading) for oxidations of NH3 and CO, respectively, suggesting practically useful synthesis method for highly active supported catalysts.

Alumina-supported cobalt catalysts in the hydrogenation of CO2 at atmospheric pressure

20 wt.% cobalt catalysts supported on pure and 5 wt.% silica-containing alumina have been prepared and characterized by X-Ray Diffraction, IR and DR-UV-vis-NIR spectroscopies and Field-Emission Scanning Electron Microscopy (FE-SEM). The presence of a cobalt-containing surface spinel phase Co3-xAlxO4 and, for the silica-containing sample, of a segregated Co3O4 phase is evident. These catalysts have been tested in CO2 hydrogenation at atmospheric pressure in steady state conditions in the temperature range 523–773 K. Both catalysts are active in CO2 hydrogenation to methane (methanation) and to CO (reverse Water Gas Shift, rWGS). CO2 hydrogenation activity is higher on freshly pre-reduced silica-free Co/Al2O3, while selectivity to methane is slightly higher on the silica-containing sample. Spent catalysts contain clustered or amorphous cobalt metal centers as active sites for methanation. The silica-containing catalyst shows slow deactivation in CO2 hydrogenation upon 13 h experiments, with quite stable or even slightly increasing rWGS activity and decreasing CH4 selectivity. This confirms previous data suggesting that, over cobalt catalysts, sites for methanation are metal centers prone to deactivation by carbon deposition. However, in contrast with what happens with unsupported and silica-supported cobalt catalysts, where deactivation is very fast, over these alumina-based catalysts carbon deposition and deactivation occur much more slowly. Sites for rWGS are unreduced cobalt centers which do not undergo such a deactivation phenomenon.

Synergetic effect of non-thermal plasma and supported cobalt catalyst in plasma-enhanced CO2 hydrogenation

Non-thermal plasma can provide an alternative to CO2 utilization under mild conditions. Understanding the effect of plasma on catalysis is highly desired. Herein, a comparative study was performed on CO2 hydrogenation under thermal-catalytic and plasma-catalytic conditions using an alumina-supported cobalt catalyst. Significant plasma-catalyst synergy was attained at the low-temperature range between 423 K and 498 K where the CO2 conversion increased up to approximately 3.6 times of the sum of that using plasma or catalyst individually. The plasma-catalytic reaction showed a significantly lower activation energy (∼40 kJ/mol), which is only half of that in the thermal catalytic reaction (∼80 kJ/mol). Kinetic analysis and DRIFTS results indicate that CO2 activation is promoted by plasma with the assistance of active H species from gas phase. Furthermore, the total H2 adsorption capacity and the coverage of irreversible adsorbed H species on the metal surface were decreased under plasma. The promotion effect is very likely due to a new reaction pathway introduced by plasma on the 15Co/Al2O3 catalyst under the conditions studied. No obvious difference in the structure and morphology changes was observed between the spent catalysts after thermal and plasma reactions.

An Experimental Study of the Performance of Isomorphically Zirconium-Substituted Mesoporous Alumina Supported Cobalt Catalysts in Fischer-Tropsch Synthesis

A series of mesoporous alumina (MA) supported cobalt (Co/MA) catalysts with MA isomorphically substituted by zirconium (Zr) were synthesised and evaluated for their performance in the Fischer-Tropsch synthesis. The Zr/(Zr + Al) atomic ratios varied from 1% - 15%. A zirconium-impregnated Co/MA catalyst prepared by wet impregnation with a Zr/(Zr + Al) atomic ratio of 5% was also evaluated to examine Zr incorporation’s effect method. The catalysts synthesised were characterised using N2 adsorption-desorption, X-ray Powder Diffraction (XRD), Transmission Electron Microscopy (TEM), and X-Ray Photoelectron Spectroscopy (XPS). It was found that Zr4+ ions were incorporated into the framework of MA and kept intact up to a Zr/(Zr + Al) atomic ratio of 5%. The cobalt dispersion and reducibility were improved as the Zr/(Zr + Al) atomic ratio increased to 50%. The performance of these catalysts for Fischer-Tropsch synthesis was evaluated using a fixed bed reactor at temperature and pressure of 493 K and 20 bar, respectively. The feed syngas had an H2/CO ratio of 2, diluted with 10% Ar. For isomorphically Zr-substituted Co/MA, the CO conversion and selectivity of diesel (C10 - C20) increased first and then decreased with increasing the Zr/(Zr + Al) atomic ratio. The maximum 38.9% CO conversion and 34.6% diesel (C10 - C20) selectivity were obtained at Zr/(Zr + Al) atomic ratio of 5%. The isomorphic substitution method was better than the wet impregnation method in CO conversion and diesel selectivity.

CO2 Reforming of CH4 on Mesoporous Alumina-Supported Cobalt Catalyst: Optimization of Lanthana Promoter Loading

CO2 Reforming of CH4 on Mesoporous Alumina-Supported Cobalt Catalyst: Optimization of Lanthana Promoter Loading

An investigation on the relationship between physicochemical characteristics of alumina-supported cobalt catalyst and its performance in dry reforming of methane.

This study deals with the development of alumina-supported cobalt (Co/Al2O3) catalysts with remarkable performance in dry reforming of methane (DRM) and least carbon deposition. The influence of Co content, calcination, and reduction temperatures on the physicochemical attributes and catalyst activity of the developed catalysts was extensively studied. For this purpose, several characterization techniques including ICP-MS, H2 pulse chemisorption, HRTEM, H2-TPR, N2 adsorption desorption, and TGA were implemented, and the properties of the developed catalysts were carefully analyzed. The impact of reaction temperature, feed gas ratio, and gas hourly space velocity (GHSV) on the reactants conversion and products yield was investigated. Use of 10%Co/Al2O3 catalyst, calcined at 500°C and reduced under H2 at 900°C in DRM reaction at 850°C, CH4/CO2 ratio of 1:1, and GHSV of 6 L.g-1.h-1 resulted in a remarkable catalytic activity and sustainable performance in long-term operation where great CO2 (96%) and CH4 (98%) conversions and high H2 (83%) and CO (91%) yields with a negligible carbon deposition (3 wt%) were attained in 100-h on-stream reaction. The good performance of the developed catalyst in DRM reaction was attributed to the small Co particle size with well-dispersion on the alumina support which increased the catalytic activity and also the strong metal-support interaction which inhibited any serious metal sintering and enhanced the catalyst stability.

Surface orientation dependent interaction of cobalt (II) precursors with alpha-alumina

The performances of alumina-supported cobalt catalysts strongly depend on Co/alumina interactions, that are poorly understood. In the present work, α-alumina surfaces are used as models of polycrystalline support, to unravel their orientation dependent behavior by GI-EXAFS. The CoII/α-alumina interactions in the dried state are investigated, with a resolution of the parallel versus perpendicular deposit formation. DFT calculations shed light on the existence of specific grafting modes. EXAFS shows that Co(OH)2 forms parallel to the R(11¯02), A(112¯0) and M(101¯0) surfaces, whatever the contact time (from 1 h to 6 days). However, a specific behavior of the C(0001) surface is observed. Whereas after one hour, the same parallel Co(OH)2 is observed, at longer times it disappears while species exhibiting long then short Co-Co distances appear. The latter is assigned to epitaxial grafting of CoII leading to a mixed phase, that is possible parallel to the C surface due to surface symmetry.

CO2 hydrogenation to liquid hydrocarbons via modified Fischer–Tropsch over alumina-supported cobalt catalysts: Effect of operating temperature, pressure and potassium loading

The effect of promoting 15%Co/Al2O3 catalyst with potassium on CO2 hydrogenation to longer-chain hydrocarbons was investigated. The catalysts used in this study were synthesized using an incipient wetness impregnation of the support with nitrate solutions. All catalysts were supported on γ-alumina and promoted with potassium (0 – 8%). The synthesized catalysts were characterized by XRD, BET, XPS, TPR and CO2-TPD analyses. The catalysts were evaluated for CO2 hydrogenation using a fixed-bed tube reactor. The CO2 conversion was found to increase with both the reaction temperature and pressure. The TPR data revealed that potassium limited the reduction of the catalyst, decreased the selectivity to methane and increased the selectivity to C2+ hydrocarbons. The maximum C2+ yield of 10.2%, with CO2 conversion of 42.3%, was obtained when 6 wt.% of potassium was added to the catalyst. It is believed that during the CO2 hydrogenation process over the catalysts that were promoted with potassium, CO2 is first converted to CO via reverse–water–gas–shift reaction, followed by subsequent hydrogenation of CO to hydrocarbons.

Promoting effect of ruthenium, platinum and palladium on alumina supported cobalt catalysts for ultimate generation of hydrogen from hydrazine

The performance of noble metal promoted-Co/γ-Al 2 O 3 bimetallic catalysts was examined for efficient H 2 generation from hydrazine decomposition. Ruthenium, platinum and palladium were chosen as promotor metals (M) to prepare three series of bimetallic catalysts (CoM x /γ-Al 2 O 3 ) via wet impregnation method. Promoting role of each noble metal was studied using various techniques like XRD, AAS, SEM, EDX, N 2 adsorption, H 2 chemisorption, TPR, and TPO. In bimetallic catalysts, all noble metals induced significant promoting effect by increasing H 2 selectivity ~12 times as compared to that of alone Co/γ-Al 2 O 3 catalyst. The catalytic activity was found strongly dependent on both the active metal contents and the type of promoters. The best performance was achieved for CoPt 0.034 /γ-Al 2 O 3 with the lowest activation energy (29.14 kJ mol −1 ) and highest H 2 selectivity (100%) in hydrazine decomposition at room temperature. • Ru, Pt, and Pd are used as the 2nd metal of bimetallic CoM x /γ-Al 2 O 3 catalysts. • Their activity is especially tested for H 2 generation from N 2 H 4 ·H 2 O decomposition. • CoRu 0.11 , CoPt 0.034 , and CoPd 0.093 catalysts exhibit optimal performance at 25 °C. • Superior activity is shown by CoPt 0.034 /γ-Al 2 O 3 catalyst with TOF of 117.8 h −1 . • Alloying Co with a noble metal is the best way to get active bimetallic catalysts.

Scavenging carbon deposition on alumina supported cobalt catalyst during renewable hydrogen-rich syngas production by methane dry reforming using artificial intelligence modeling technique

Methane dry reforming is a thermo-catalytical process that utilizes two principal components of greenhouse gases for the production of hydrogen-rich syngas . One major shortcoming of the methane dry reforming as a potential route for renewable hydrogen-rich syngas production is catalyst deactivation through carbon deposition . In this study, an artificial neural network approach was employed for predictive modeling of the deactivation of alumina supported cobalt catalyst used to catalyze methane dry reforming reaction. The effect of methane/carbon dioxide (CH 4 /CO 2 ) ratio, reaction temperature and nitrogen (N 2 ) flowrate on the carbon deposition were investigated using full factorial experimental design . Two artificial neural network modeling techniques namely multilayer perceptron neural network (MLPNN) and radial basis function (RBFNN) were employed for the prediction of carbon deposition per gram catalyst using data obtained from 170 experimental runs. The hidden neurons were optimized to obtain 16 and 20 units respectively for the MLPNN and the RBFNN resulting in the network architecture of 3, 16, 1 and 3, 20, 1, respectively. The statistical analysis of the network performance resulted in mean standard error (MSE) values of 0.048 and 0.00285 for training the MLPNN algorithm above and below stoichiometric conditions with corresponding R 2 values of 0.945 and 0.965. While MSE values of 0.0073 and 0.00015 were obtained for the training of the RBFNN algorithm above and below stoichiometric conditions with R 2 of 0.987 for both cases. Base on the statistical analysis the RBFNN model was adjudicated as a better predictor of the carbon deposition during the hydrogen-rich syngas production than the MLPNN model. The three input parameters were found to have varying levels of importance in the prediction of the carbon deposition. The reaction temperature was observed to be the most important parameters that influence the prediction of carbon deposition above stochiometric while CH 4 /CO 2 was the most important parameters that influence the prediction of carbon deposition below stoichiometric conditions. • MLPNN and RBFNN models were developed and employed to predict carbon deposition on Co/αAl 2 O 3 . • Optimized hidden neurons with 16 and 20 units respectively were obtained for MLPNN and RBFNN. • Levenberg-Marquardt algorithm was employed to train the MLPNN and RBFNN. • Both MLPNN and RBFNN accurately predict carbon deposition with minimal residuals. • RBFNN with MSE of 0.00015 and R 2 of 0.985 predicts better than MLPNN with MSE of 0.00285 and R 2 of 0.965

Hydroxyapatite as a new support material for cobalt-based catalysts in Fischer-Tropsch synthesis

Hydroxyapatite [HAP, (Ca10(PO4)6(OH)2)] is an emerging catalytic support possessing exciting features such as high thermal and mechanical strength, chemically stable with low water solubility along with tunable porosity and acid-basic character. Despite of these interesting characteristics, it has not yet been investigated in Fischer-Tropsch (FT) synthesis. Herein, for the first time, HAP-supported cobalt catalysts (Co/HAP) prepared by conventional incipient wetness impregnation method were examined in the FT synthesis process. The catalytic performance of these catalysts was compared with alumina-supported cobalt catalysts (Co/Alumina). HAP support was found to exhibit considerably less acid-site density, consequently, reducing detrimental interactions of the support with cobalt precursors leading to hardly reducible Co species that are generally observed with its alumina counterpart. Co/HAP catalysts exhibit relatively larger Co particle sizes (~9 nm versus ~6 nm, as observed from TEM analysis) and better Co reducibility when compared to its counterparts on alumina. FT synthesis at 20 bar, 220 °C and H2/CO = 2.1 showed that the CO conversion was higher on the catalysts (10 wt% Co loading) using HAP as a support material when compared to alumina. Under different testing conditions (220 or 230 °C) using the Co/HAP catalyst, the C5+ selectivity was in the range of 82–88%, whereas the methane selectivity was about ~10%.

Conversion of Carbon Monoxide into Methanol on Alumina-Supported Cobalt Catalyst: Role of the Support and Reaction Mechanism—A Theoretical Study

Density functional theory (DFT) was used to calculate the step-by-step hydrogenation of carbon monoxide (CO) to form methanol over a Co4 cluster/Al2O3 surface. A three-dimensional Co4 tetrahedral structure was selected to explore its interaction with the supporting Al2O3 (104) surface. Co4 chemically reacted with Al2O3 to form a new chemical system. The calculated results show that Al2O3 support has strengthened the Co4 catalyst during the reaction since the formation of the Co–O bond. Loading Co4 on the Al2O3 surface increases CO adsorption ability but decreases the dissociation ability of C–O to produce hydrocarbons. As such, CH3OH formation becomes more favorable both kinetically and thermodynamically on Co4/Al2O3. In CO hydrogenation, methanol was synthesized through a CO reaction with hydrogen via either an Eley–Rideal or Langmuir–Hinshelwood pathway to form the intermediates C*-O-H, H-C*-OH, H2-C*-OH, and finally the hydrogenation of H2-C*-OH to methanol with both hydrogenation steps forming C*-OH and final product as rate-limiting. These results showed that the interaction between Co, Al2O3 and H2 pressure can change the pathway of CO hydrogenation on Co/Al2O3 and it may, therefore, influence distribution of the final products.

The effect of chelating anions on the retention of Co(II) by γ-alumina from aqueous solutions under the unadjusted pH condition of supported catalyst preparation

This study analyzes the effect of the addition of acetate, citrate, and nitrilotriacetate anions on the retention of Co(II) cations by the γ-alumina surface in view of the preparation of alumina supported cobalt catalysts. The emphasis was placed on the way the Co(II) species attach to the solid surface when adsorbed from aqueous solutions under the unadjusted pH condition. The individual adsorption isotherms onto γ-Al2O3 support for cobalt and a given ligand were determined by following the solution depletion method in single-solute and bi-solute systems. These adsorption data were supplemented by the results of potentiometric titrations. In the case of bi-solute systems, the adsorption procedures allowed either co-impregnation of γ-alumina with equimolar solutions of cobalt and ligand salts or pre-impregnation of γ-alumina with the ligand anions and the subsequent adsorption of cobalt. Changes in the pH of the equilibrium solid-liquid suspension were also monitored along the adsorption isotherms. The adsorption of Co(II) onto γ-Al2O3 in the presence of acetate and nitrilotriacetate led to the formation of the type A (i.e., solid-metal-ligand) ternary complexes. The use of citrate anions together with Co(II) cations was shown to improve the impregnation process through the formation of ternary complexes of type B (i.e., solid-ligand-metal). The comparison with a system containing tricarballylate anions allowed concluding that the presence of the hydroxyl group in the citrate anion enhanced its affinity for the alumina surface by contributing to the inner-sphere character of its surface-bound complexes.

Fuel-Rich Combustion Synthesized Co/Al2O3 Catalysts for Wax and Liquid Fuel Production via Fischer–Tropsch Reaction

Alumina supported cobalt catalysts were synthesized for Fischer–Tropsch (FT) reaction using combustion synthesis (CS) method via the redox reaction of hexamethylenetetramine and cobalt nitrate with equivalence ratios (ϕ) of 1, 1.2, and 1.5. Higher equivalence ratios (ϕ > 1.0) were selected to increase the synthesis temperature and thereby decrease the formation of cobalt aluminates. Chemisorption and XPS studies of CS(ϕ = 1.2) and CS(ϕ = 1.5) catalysts showed high degree of reduction, high metal dispersion, and decreased formation of cobalt aluminates compared to CS(ϕ = 1) catalysts. Higher FT activity was observed for catalysts synthesized with equivalence ratios of 1.2 and 1.5 compared to the catalysts synthesized with ϕ = 1. Simultaneously, the hydrocarbon product spectrum shifted from predominantly waxes (C24+) for CS(ϕ = 1) catalysts to mixed fractions of liquid fuel (C6–C24) and waxes for CS(ϕ = 1.2) and CS(ϕ = 1.5) catalysts. This work investigates the impact of CS stoichiometry on catalyst propert...

Cobalt Catalysts Preparation and Characterization over Alumina Support for Fischer Tropsch Synthesis

Abstract An investigation was done to develop and characterize the alumina supported cobalt catalyst for Fischer-Tropsch Synthesis to produce biodiesel from biomass with the aim to produce alumina-supported cobalt catalysts containing 7 to 19 wt.% cobalt content. By using incipient wetness impregnation of γ-Al2O3 supports with cobalt nitrate hexahydrate with ethanol and distilled water solutions; the 14 wt.% cobalt content in catalyst was achieved. Nitrogen adsorption-desorption, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray fluorescence (XRF), H2temperature programmed reduction (H2-TPR), temperature programmed desorption (TPD), temperature programmed oxidation (TPO) and carbon monoxide chemisorption were used for the characterization of the catalysts to attain an appropriate cobalt catalyst. In order to investigate the effect of the impregnation on the crystalline size, surface area and cobalt content, three different impregnation methods with various durations were investigated. In addition, increasing the impregnation duration increased the cobalt content and its dispersion. Based on results, positive effect of the alumina support and impregnation duration on the crystallite size, surface area, and pore diameter, reducibility of the catalyst and cobalt dispersion were investigated. Thus, cobalt catalyst for using in fixed bed reactor to produce biodiesel from biomass through Fischer-Tropsch Synthesis was prepared and characterized.

CO Hydrogenation on Cobalt-Based Catalysts: Tin Poisoning Unravels CO in Hollow Sites as a Main Surface Intermediate.

Site poisoning is a powerful method to unravel the nature of active sites or reaction intermediates. The nature of the intermediates involved in the hydrogenation of CO was unraveled by poisoning alumina-supported cobalt catalysts with various concentrations of tin. The rate of formation of the main reaction products (methane and propylene) was found to be proportional to the concentration of multi-bonded CO, likely located in hollow sites. The specific rate of decomposition of these species was sufficient to account for the formation of the main products. These hollow-CO are proposed to be main reaction intermediates in the hydrogenation of CO under the reaction conditions used here, while linear CO are mostly spectators.

Deactivation of alumina supported cobalt FT catalysts during testing in a Continuous-stirred tank reactor (CSTR)

A set of alumina supported cobalt catalysts was prepared, varying the synthesis method and formulation to produce a range of cobalt particle sizes. A combination of degree of reduction (DOR) measurements and H2 chemisorption was used to calculate the cobalt particle sizes on the fresh catalyst samples (5–19nm). The catalysts were pre-reduced and encapsulated in wax prior to testing for Fischer-Tropsch (FT) activity in a continuous-stirred tank reactor (CSTR) system for between 500 and 6000h on-line. The catalysts all demonstrated rapid deactivation over the first 200h of FT testing, with the catalysts with the highest initial activity deactivating most rapidly. Characterisation of the discharged catalysts samples using XRD, TEM and H2 chemisorption indicated that the cobalt particles had undergone a sintering process consistent with an Ostwald ripening mechanism. Catalyst stability in CSTR testing can be enhanced by the presence of large cobalt particles (>20nm).

Modified product selectivity in Fischer-Tropsch synthesis by catalyst pre-treatment

Fischer-Tropsch Synthesis (FTS) yields a spectrum of products with carbon lengths of 1 to upwards of 100 units. In order to make use of the full spectrum of hydrocarbon fractions, particularly the heavier units, secondary processing is required. Modifying the FTS product distribution and catalyst activity in order to decrease the amount of long chain hydrocarbons (C25+) may allow significant simplification of FTS based processes. To this end we report the results of in-situ pre-treatment of alumina supported cobalt catalysts (Co/Ru/La – Al2O3) with acetylene in a fixed-bed reactor. It is postulated that acetylene dissociation and dehydrogenation resulted in the generation of carbidic and CxHy species on the catalyst surface. The formation of these carbonaceous species on different active sites of the catalyst surface following pre-treatment also significantly altered the FTS product distribution by affecting the extent and pathway of 1-olefin secondary reactions. It is thought that these changes resulted from decreased incorporation of 1-olefins in further chain growth and a decrease in secondary hydrogenation rate. The amount of heavy hydrocarbons (waxes) produced was reduced by more than two-fold.

Optimization of solvent-free mechanochemical synthesis of Co/Al2O3 catalysts using low- and high-energy processes

In this work, alumina-supported cobalt (Co/Al2O3) catalysts were prepared using new solvent-free mechanochemical synthesis methods: low-energy vibratory ball milling (Fritsch, Pulverisette 0) and high-energy planetary ball milling (Retsch, PM 100). γ-Al2O3 supports and Co/Al2O3 catalysts after mechanochemical treatments were characterized using a combination of techniques. The study of solid particles revealed the abrasion and fragmentation phenomena of porous γ-Al2O3 particles and pore filling under milling. Functional cobalt particles introduced by the mechanochemical synthesis were observed to be preferentially localized on the outer surface of the alumina supports. High Fischer–Tropsch reaction rates were obtained with the catalysts prepared by optimized mechanochemical synthesis conditions. The enhanced catalytic performance can be attributed to the relatively high dispersion of cobalt and the absence of inert cobalt aluminates which are usually present in the catalysts synthesized by the conventional impregnation.

Modification of mesoporous alumina as a support for cobalt-based catalyst in Fischer-Tropsch synthesis

The high surface area, large pore volume and pore diameter mesoporous alumina was synthesized using pluronic F127 as a structure-directing agent. This material was employed as a support for the cobalt catalyst in Fischer-Tropsch Synthesis (FTS). During the catalyst synthesis, impregnation of cobalt nitrate aqueous solution caused a collapse in the structure and a drastic decline in the textural properties of the mesoporous alumina. Organic solvents such as acetone and ethanol were employed instead to realize their impact on the corresponding cobalt catalysts stability. The synthesized catalysts were characterized using BET, XRD, TEM, TPR, and H2 chemisorption. The catalysts prepared using organic solvents were found to retain the textural properties of the mesoporous alumina. The process conditions including temperature, pressure, and GHSV were optimized adopting Taghuchi experimental design. Then, all catalysts were tested in FTS utilizing syngas with H2/CO ratio 2.0, at optimized conditions of 230°C, 400psi, and GHSV of 900h−1. The Co/γ-Al2O3 catalyst was also synthesized and tested in FTS for the comparison study. The physico-chemical properties of the synthesized catalysts were correlated with their performances in FTS. The mesoporous alumina supported cobalt catalyst using ethanol as a solvent in its preparation was found to be the most stable in the series and it showed 8.3% higher CO conversion, 3.3% higher C5+ selectivity, and 2.7% lower CH4 selectivity as compared to those shown by Co/γ-Al2O3 catalyst. Higher cobalt loadings of 22.5 and 30wt% were also prepared using ethanol solvent and examined in FTS. Doubling the cobalt content from 15 to 30wt% of the catalyst resulted in stable catalyst with 23% increase in the hydrocarbon yield and 4% improve in C5+ selectivity.