Cobalt Particles Research Articles

Studies on the Fischer-Tropsch synthesis over RuCo/SiC-Al2O3 structured catalyst

RuCo/SiC-Al2O3 catalysts were with enhancing thermal conductivity for the Fischer-Tropsch Synthesis (FTS) were designed and manufactured. The SiC-Al2O3 support was extruded by Lab scale extruder and then foamed by the marumerizer. Catalysts were prepared by an incipient wetness impregnation method. All the prepared catalysts were characterized by SEM-EDX, XRD, TPR, TPD, XPS, ICP and N2-physisorption techniques. The catalytic performance was evaluated at T = 210–230 °C, P = 20 bar and GHSV of 1,000 h−1 in a fixed bed reactor system. The CO conversion over RuCo/nSiC-Al2O3 catalysts was increased by 10% compared to RuCo/Al2O3 catalyst at 210 °C. Furthermore, the selectivity of methane was similar or less than RuCo/Al2O3 catalyst. It was shown that the CO conversion increased with increasing the SiC content from 5 to 15 wt%, and then decreased. The RuCo/15SiC-Al2O3 catalyst showed higher CO conversion than other catalysts under the tested conditions. This is because the 15 wt.% SiC addition ratio is the most advantageous between thermal conductivity improvement and aggregation of cobalt particles.

Liquid-Phase Hydrogenation of Nitriles to Amines Facilitated by a Co(II)/Zn(0) Pair: A Ligand-Free Catalytic Protocol.

The given report introduces a simple and user-friendly in situ method for the production of catalytically active cobalt particles. The approach circumvents the use of air- and moisture-sensitive reductants as well as the application of anhydrous Co-precursor salts. Accordingly, the described catalytic system is readily assembled under open-flask conditions by simply combining the components in the reaction vessel. Therefore, the arduous charging procedure of the reaction autoclave in a glovebox under an inert gas atmosphere is no longer necessary. In fact, the catalytically active material is obtained upon treatment of readily available Co(OAc)2·4 H2O with benign commercial Zn powder. The catalytic performance of the resultant material was tested in the heterogeneous hydrogenation of nitriles to the corresponding primary amines. Both activity and selectivity of the cobalt catalyst are significantly enhanced if a triflate-based Lewis acid and ammonia is added to the reaction mixture.

The influence of biologically produced sulfide-containing solutions on nickel and cobalt precipitation reactions and particle settling properties

Wastewater from mining and metallurgical activities provides a potential profit source for recovering leftover but valuable metals such as nickel (Ni) and cobalt (Co). For this, sulfide precipitation is an attractive option, although the cost of providing chemical sulfide and the poor settling of metal sulfides discourage its application. As an alternative, sulfide-containing solution (i.e. biogenic sulfide) can be produced on site by sulfate reducing bacteria that can utilize sulfate present in the wastewater, thus reducing reagent and transportation costs. Additionally, the various components in biogenic ‘sulfide’, i.e., bacterial cells, cell by-products and exopolymer may enhance the settling properties of Ni and Co sulfide, thus improving metal recovery. In this project, the effect of using chemical sulfide and four biogenic sulfide-containing solutions for Ni and Co precipitation and settling was evaluated. The biogenic sulfide-containing solutions were obtained from four bioreactors fed with volatile fatty acids (VFA), leachate from fermentation of municipal solid waste, ethanol and lactate, respectively. The results showed that VFA-fed biogenic sulfide enhances the Ni precipitation reaction as compared with chemical sulfide, whereas Co was effectively precipitated from solution (> 98%) regardless of the sulfide source and metal concentration. Settling extent of both metal sulfides reached up to 80–90% in lactate-fed biogenic sulfide, while <20% of the precipitates settled by reaction with chemical sulfide. Phosphate was the main component affecting particle settling whereas acetate and sulfate exhibited a smaller influence. This research highlights the importance of the different components from the biogenic sulfide-containing solutions in the precipitation and settling of Ni and Co precipitates, demonstrating enhanced prospects of metal recovery through biological sulfate reduction process.

Facile synthesis of cobalt nanoparticles embedded nitrogen-doped carbon nanotubes as electrocatalyst of hydrogen evolution reaction

Designing and researching efficient non-precious metal catalysts is of great significance for the development of electrocatalysis in hydrogen evolution reaction (HER). Cobalt nanoparticles embedded in nitrogen-doped carbon nanotubes (Co-NCNT) was synthesis by a facile method. Using CoCl2 · 6H2O and melamine as raw material, products with different morphologies and properties were obtained at different temperatures. Among them, the material has the best HER performance at 700 °C, and the overpotential has reached 251 mV when the current density is 10 mA · cm−2. At the same time, the Tafel slope of the sample is 79 mV/dec. The improvement in HER performance was attributed to the N-doping of carbon nanotubes with nano-scale cobalt particles.

Selective production of naphthalene from methanol by photocatalysis on nanostructured cobalt particles

Abstract The environmental impact associated with carbon dioxide emissions has prompted a wide array of research projects aimed at the chemical reduction of CO2 or its conversion to useful feedstocks with solar energy. Using simple starting reagents, we have demonstrated that when methanol is exposed to visible light overnight in a glass reaction chamber pressurized with carbon dioxide and containing nanostructured cobalt particles, the overwhelmingly major nonpolar semi-volatile product is naphthalene. Naphthalene is the simplest polycyclic aromatic hydrocarbon, and can be used as a precursor to many other complex aromatics. Current industrial processes remove it from coal tar or petroleum during the refining and distillation steps. The process reported here is much greener, albeit on a much smaller scale. The cobalt particles were synthesized from a cobalt salt to exhibit surface nanostructures, and were characterized by scanning electron microscopy (SEM), electron dispersive spectroscopy (EDS), and X-ray diffraction (XRD). After irradiation, any products generated in the reaction chamber were extracted with dichloromethane and then analyzed by gas chromatography-mass spectrometry (GC–MS).

Effects of metallic cobalt crystal phase on catalytic activity of cobalt catalysts supported on carbon nanotubes in Fischer–Tropsch synthesis

The effects of metallic cobalt crystal phase on catalytic activity of cobalt catalysts in the Fischer–Tropsch synthesis were investigated in a continuous spinning basket reactor. The cobalt catalysts were prepared by impregnation of the cobalt active phase in a microemulsion system on multiwall carbon nanotube supports. A series of cobalt catalysts with different Co particle sizes was prepared by variation of the water-to-surfactant molar ratio from 2 to 12 in the microemulsion system. The X-ray diffraction results validate a complex composition of cobalt phases containing cobalt oxides and metallic cobalt with hexagonal close-packed and face-centered cubic phases. The results show that larger cobalt particles exhibit more face-centered cubic and less hexagonal close-packed metallic cobalt. The experimental results show that the catalysts with higher fractions of hexagonal close-packed phase exhibited higher conversion in the Fischer–Tropsch reaction.

Payne effect and damping properties of flower-like cobalt particles-based magnetorheological elastomers

Abstract Flower-like particles can improve particle/matrix interface of magnetorheological elastomers (MREs) and have some different influences. To analyze the Payne effect and damping properties of the flower-like cobalt particles-based MRE (FCP-MRE), the spherical cobalt particles-based MRE (SCP-MRE) and the coupling agent modified cobalt particles-based MRE (M-SCP-MRE) were prepared for comparison. Considering the explanation of the Payne effect of MREs is not clear, a schematic diagram of the internal structure change of MREs during the shearing process was established to clarify their Payne effect, which was further proved by analyzing their damping properties. Several methods for evaluating the Payne effect of MREs were also provided. The results indicated that the special morphology of flower-like particles caused the MREs has higher storage modulus as well as higher energy dissipation density. The special morphology of flower-like cobalt particles also reduced the Payne effect of MRE because of its higher crosslink density. Different interface combinations also affect the performance of MREs.

Ruthenium and cobalt bimetal encapsulated in nitrogen-doped carbon material derived of ZIF-67 as enhanced hydrogen evolution electrocatalyst

Due to the high price and low reserve of platinum (Pt) base precious catalysts, and non-noble metal catalysts are unable to catch up with the overpotential of Pt-based electrocatalysts, more and more attention has been paid to study low-noble metal catalysts. In this work, we report a highly active and steady electrocatalyst with ruthenium and cobalt bimetal encapsulated in nitrogen-doped carbon material derived of ZIF-67. ZIF-67 was firstly calcined under vacuum to form nitrogen-doped carbon containing the cobalt particles, and then made Ru atoms partly replaced some Co atoms to prepare the ruthenium and cobalt bimetal catalyst. The electrocatalyst is prepared with low loading Ru (3.5 wt%) and has an excellent hydrogen evolution reaction (HER) catalytic performance in acidic and alkaline medium. It displays the overpotential of only 23 mV at 10 mA cm−2 in alkaline solution, which even exceeds commercial 20 wt% Pt/C catalyst. Besides, the current density of the electrocatalyst is only reduced by less than 10% after continuous operation of 10,000 s, indicating excellent durability.

Surface Functionalization of Metal-Organic Framework Prior to TiO2 Tethering for Oxygen Reduction Catalysis in Alkaline Media

Oxygen reduction reaction (ORR) is one of the most studied reactions for clean energy devices such as fuel cells and metal-air batteries due to its intrinsically sluggish kinetics which often limits device performance. Non-precious transmission metal oxides (TMO) such as Fe3O4, MnOx and Co3O4[1] have been intensively probed as alternatives to platinum-based catalysts. To supplement low electronic conductivity of TMOs, they are often dispersed on a highly conductive carbon nanostructure with a large surface area, maximizing catalytically active sites per volume and mass. We employ a hybrid structure where both cobalt and cerium nitrate salts with a ligand called [1,1’-Biphenyl]-4,4’-dicarboxylic acid create an MOF (MOF-Ce-Co) with extreme surface area and excellent electronic conductivity using the hydrothermal process and pyrolysis. While this structure is conductive, its conductivity can be improved with the functionalization of cerium particles. Specifically, Ce(IV) complexes have been reported to show superior rates of phosphonate ester bond cleavage compared to other metal oxides. The unprecedented activity of Ce(IV) has been attributed to the role of the Ce(IV) 4f orbitals that can mix with the orbitals of the P=O bond to form hybrid orbitals[2]. To functionalize cerium, phosphoric acid is used to bind a phosphate group onto cerium oxide. This gives rise to a penta-coordinate intermediate that is susceptible to a nucleophilic attack[2]. The treated MOF-Ce-Co is then hydrothermally reacted (at 160 ºC for 24 h) with the precursor P25, thus creating MOF-Ce-Co with TiO2 attached. Results have indicated that phosphate groups not only absorb cerium nanoparticles, but TiO2 thus resulting in enhance performance in terms of current density, and onset/half-wave potential as seen in both CV and LSV data. FT-IR results indicate that an absorption of 1040 cm-1 (corresponding to a phosphate group) appeared once MOF-Ce-Co was treated with phosphoric acid. An X-ray analysis showed that both samples (MOF-Ce-Co and MOF-Ce-Co with TiO2) had cerium and cobalt particles, however, MOF-Ce-Co with TiO2 had an additional peak at 56º, indicating that presence of TiO2 (Anatase). Hence, the improved performance of the treated MOF is the result from functionalization. This project was funded by NASA Advanced STEM Training and Research (ASTAR) Fellowship.

Three-dimensional porous carbonaceous network with in-situ entrapped metallic cobalt for supercapacitor application

Herein, we outline the fabrication of highly porous three-dimensional carbon-fiber network anchored with uniform metallic cobalt (Co) via electrospinning and subsequent post-modification approaches. First, cobalt acetate solution saturated electrospun polyacrylonitrile (PAN) nanofibrous mat was subjected to sodium borohydride (NaBH4) solution which results in the fabrication of three dimensional (3D) hierarchical multilayer network. Restructuring of the 2D mat into multilayered sponges with metal particles entrapment is attributed to the in-situ generated hydrogen gas into the interconnected pores of the fibrous network simultaneous with reduction of cobalt salt into metallic cobalt by NaBH4. The resulting mesh was stabilized and carbonization at inert atmosphere to obtain metallic cobalt (Co) embedded 3D carbon nanofibrous networks (Co@3D-CNFs). Physicochemical characterization and electrochemical analysis were performed. Results show carbon network was found to be expanded with bubbling like structures often embedded metallic Co nanoparticles. X-ray diffraction (XRD) pattern confirms the existence of the metallic cobalt particles on the carbon fiber networks. Furthermore, we establish a resulting composite (Co@3D-CNFs) identify the enhanced electrochemical performance having specific capacitance 762 F g−1 compared to 173 and 180 F g−1 for corresponding @3D-CNFs and 2D carbon nanofiber network with cobalt doped (Co@2D-CNFs) counterparts, respectively. The assembled Co2@3D-CNFs//NGH ASC device exhibits a high energy density 24.6 W h Kg−1 at 797 W kg−1 power density with an operating voltage of 1.6 V (vs Ag/AgCl). The device further shows good capacitance retention (90.1%) after 5000 cycles. This research shows the simple and cost-effective strategy to make metallic particles embedded 3D porous carbonaceous electrode materials which can have great potential for energy storage application.

Accurate and sensitive determination of lead in black tea samples using cobalt magnetic particles based dispersive solid-phase microextraction prior to slotted quartz tube-flame atomic absorption spectrometry

Newly developed combination of magnetic cobalt particles based dispersive solid-phase microextraction (Co-MP-DSPME) and slotted quartz tube attached flame atomic absorption spectrometry (SQT-FAAS) was utilized to determine lead at trace levels in tea samples. Co-MPs’ adsorbent properties were tested and validated for their selectiveness to lead. Only with a few and short extraction steps (i.e. adding MPs, mixing, decanting and eluting) analyte was extracted from sample solution rapidly and efficiently. Limit of detection (LOD) and limit of quantification (LOQ) for the developed method (Co-MP-DSPME-SQT-FAAS) were found to be 7.77 µg/L and 25.9 µg/L, respectively. Matrix matching strategy was performed and outcomes indicated that the developed method is applicable with the high percent recovery values of 110.1 ± 4.5 and %102.9 ± 4.2 for 100 and 300 µg/kg lead standard spiked black tea samples, respectively. The method was also applied to standard reference material to check the accuracy of the method.

Electrochemical Synthesis and Properties of the Composite Material ITO/Polypyrrole-Benzoic: Cobalt for Electronic Storage Applications

We report on the synthesis and characterization of cobalt microparticles insertion into the composite material poly [4-(pyrrol-1-yl methyl) benzoic acid]. These were deposited on indium tin oxide (ITO) coated glass substrates. Poly [4-(pyrrol-1-yl methyl) benzoic acid] films, 2.3 µm thick, were prepared by electrochemical oxidation of [4-(pyrrol-1-yl methyl) benzoic acid] monomer in an acetonitrile medium. The insertion of cobalt particles was carried out by immersing the modified electrode (ITO/polymer) in a cobalt metal salt solution in order to complex the Co2+ cations with the COO− carboxylic groups present in the polymer film, followed by an electrochemical reduction of the polymer–cobalt complex to precipitate cobalt in the form of metal microparticles in the polymer film. The electrochemical study by cyclic voltammetry indicated the insertion of cobalt into the polymer films by complexation and electroreduction. The characterization of the composite material by electrochemical impedance spectroscopy, scanning electron microscopy, X-ray fluorescence and X-ray diffraction spectroscopies confirmed the presence of approximately 2 µm sized cobalt aggregates dispersed in the polymer film. The study of the magnetic behavior of the composite material showed an improvement with the cobalt charge increase.

Improving electrochemical properties of Lithium–Sulfur batteries by adding a catalyst-embedded interlayer

To improve lithium–sulfur (Li–S) battery performance, a new interlayer film of embedded palladium cobalt (Pd3Co) particles is developed. Pd3Co particles on multi-walled carbon nanotubes (MWCNTs) are synthesized by using a modified polyol method. The synthesis of Pd3Co on MWCNTs is confirmed by X-ray diffraction, transmission electron microscopy and energy-dispersive X-ray spectroscopy. The interlayer film is prepared through a filtration method using these powders. Li–S batteries with this interlayer have electrochemical properties superior to those with an MWCNT interlayer (0.2, 0.5, and 2.0 C-rates). At 0.2 and 0.5 C-rates, Pd3Co/MWCNT-interlayer cell achieves a better performance than MWCNT-interlayer cell during 200 cycles. In addition, there is a definite performance difference for 2.0 C-rate during 300 cycles. The discharge capacities for the first and 300 cycles for the MWCNT-interlayer cell are 869 mAh g−1 and 525 mAh g−1, respectively, whereas those for a Pd3Co/MWCNT-interlayer cell are 953 mAh g−1 and 752 mAh g−1, respectively. These improvements are resulted from the catalytic role of Pd3Co, which assists the reaction of polysulfide formation/deformation.

Evolution of cobalt species in glow discharge plasma prepared CoRu/SiO2 catalysts with enhanced Fischer-Tropsch synthesis performance

Glow discharge plasma was applied to substitute thermal calcination during catalyst preparation. Evolution of cobalt particles in cobalt-ruthenium based catalysts at different stages (fresh prepared, reduced, after Fischer-Tropsch synthesis (FTS) reaction) were studied using a series of characterization techniques. Glow discharge plasma can be developed as an efficient technique to decompose metal salt. Cobalt dispersion was greatly enhanced by glow discharge plasma treatment, and higher initial cobalt dispersion was found on the one with lower treating intensity. However, cobalt crystallites generated by plasma treatment below certain intensity had poor thermal stability, they were tended to aggregate into large particles during reduction and reaction processes, and thus severe deactivations were observed during FTS tests. Besides cobalt sintering, mass transfer limitation at high FTS activity due to the pore plugging by long-chain hydrocarbons was also one of the important reasons for deactivation. The CRS-P140 catalyst with higher plasma treating intensity combined relatively high cobalt dispersion, high cobalt reducibility and relatively stable cobalt distribution during reduction or reaction, showed a high FTS activity with less activity loss.

A new free light chain immunoassay shows better agreement with the quantification of the serum protein electrophoresis M-protein compared to a nephelometric assay in patients with multiple myeloma

The continuing development of nanotechnology necessitates the reliable assessment of potential adverse health consequences associated with human exposures. The physicochemical properties of nanomaterials can be responsible for unexpected interactions with components of classical toxicity assays, which may generate erroneous interpretations.In this paper, we describe how particle interference can be observed in in vitro toxicity tests (CellTiter Blue, CyQUANT, WST-1 and CellTiter-Glo assay) and in cell biology tests using flow cytometry (cell cycle analysis). We used cobalt oxide (Co3O4) particles as an example, but these assays can be performed, in principle, regardless of the nanoparticle considered. We have shown that cobalt particles interfere with most of these tests. We adapted the protocol of the CellTiter-Glo assay to circumvent this interference and demonstrated that, using this protocol, the toxicity level is consistent with results obtained using the clonogenic assay, which is considered to be the reference test.Before assessing particle toxicity using in vitro toxicity tests, interference testing should be performed to avoid false interpretations. Furthermore, in some cases of interference, protocol adaptation can be considered to allow the reliable use of these quick and convenient in vitro tests.

Capturing the interconnectivity of water-induced oxidation and sintering of cobalt nanoparticles during the Fischer-Tropsch synthesis in situ

Supported nano-sized metal crystallites as catalysts in the Fischer-Tropsch synthesis have become a major research focus due to their high mass specific surface area and resulting lower cost. Such small supported cobalt crystallites have been reported to show a very different resistance with regard to deactivation compared to larger cobalt particles. The Fischer-Tropsch product water is reported to have a severe effect on the deactivation of cobalt-based Fischer-Tropsch catalysts. Compared to other water-induced deactivation mechanisms, hydrothermal sintering of cobalt nanoparticles is fairly well established in literature. A previously hypothesised interconnection between oxidation of cobalt nanoparticles and hydrothermal sintering has – for the first time – been captured in situ in the presented study. High concentrations of water induce oxidation of the cobalt nanoparticles increasing their mobility and resulting in crystallite growth via particle migration and coalescence whilst in the oxidised state. A well-defined model catalyst comprising highly dispersed cobalt nanoparticles on a relatively inert exfoliated graphite support in combination with an in situ magnetometer allowed for these observations, which resulted in irreversible deactivation of the catalyst.

Effect of cobalt metal loading on Fischer–Tropsch synthesis activities over Co/γ-Al2O3 catalysts: CO conversion, C5+ productivity, and α value

This study investigates the effect of cobalt loading (5–20 wt% Co) on the physical properties of the alumina support and cobalt particle size of Co/γ-Al2O3 catalysts for Fischer–Tropsch synthesis (FTS) reaction (T = 210 °C (set), P = 20 bar, H2/CO = 2). To characterize the catalysts and correlate these characteristics with their catalytic activities in FTS, N2 adsorption, inductively coupled plasma, X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) studies were conducted. N2 adsorption and XRD analyses showed that as the cobalt loading was increased up to 15 wt%, the number of cobalt oxide particles increased by the direct interaction between cobalt oxide and the alumina support surface, but that when the cobalt loading was further increased to 20 wt%, the particle size of the cobalt oxide increased abruptly due to the additional cobalt loading on the previously loaded cobalt oxide. These physical properties of the supported cobalt catalysts were attributed to the pore structure of the alumina support. From the TEM micrographs, the size of cobalt particles was roughly estimated to increase from 20 to 50 nm at a cobalt loading up to 15 wt% Co/γ-Al2O3 to 70–100 nm at 20 wt% cobalt loading. For the 5–15 wt% Co/γ-Al2O3 catalysts, CO conversion and C5+ liquid oil productivity increased with increasing cobalt loading because they were strongly proportional to the number of cobalt particle active sites. However, the 20 wt% Co/γ-Al2O3 catalyst showed the highest value of α because the larger cobalt particles increased the opportunity for chain growth. The XPS data also supported the greater reducibility of the cobalt species in 20 wt% Co/γ-Al2O3 and hence its larger size compared to that at low cobalt loading.

A cleaner and energy-saving technology of vacuum step-by-step reduction for recovering cobalt and nickel from spent lithium-ion batteries

Waste power banks (a kind of lithium-ion battery) are widely generated along with the growing widespread use of mobile phone. Vacuum carbon reduction is encouraged to recover cobalt and nickel from spent lithium-ion battery. However, the mixed nickel and cobalt particles are difficult to be further separated. Recovering cobalt and nickel respectively from the electrode powders is important to improve the recovery value of spent lithium-ion battery. According to the analysis of Gibbs free energy of the reduction process of Ni2+ and Co2+, we proposed a cleaner technology of step-by-step vacuum carbon reduction to recover nickel and cobalt in sequence from the electrode powder of spent lithium-ion batteries. The Ni2+ and Co2+ in the spent lithium-ion battery are reduced into nickel and cobalt in vacuum tubular furnace at the temperatures of 691 °C and 873 °C respectively. Nickel and cobalt can be separated in sequence by magnetic separation at the reduction products of different temperatures. Additionally, for energy saving and accurate reduction, we analyzed the heat transfer in the vacuum reduction process and constructed the models for computing the true temperature of electrode powder in crucible. The models are used to compute the accurate reduction temperatures for Co2+ and Ni2+. It will greatly reduce the energy cost in the reduction process which be attributed to sustainable development. The models also can guide the structure design of vacuum tubular furnace for improving the efficiency of heat transfer.

Supercapacitive performance of a ternary nanocomposite based on carbon nanofibers with nanostructured chitosan and cobalt particles

In the present work, efforts have been made to enhance the performance of carbon nanofibers in charge storage applications that are hindered by their inert surface and high graphitic content. In this regard, a ternary nanocomposite of carbon nanofibers-chitosan and cobalt nanoparticles (CNF-CS/Co) has been prepared via simple strategy. The material characterization of the nanocomposite revealed a large surface area of 188.3 m2 g-1. The electrochemical characterization of CNF-CS/Co as a supercapacitor electrode has resulted in a high specific capacitance of 438.6 F g-1 at 1 A g-1, which has been found to greatly improved from that of pristine CNF (81.3 F g-1), Co (129.7 F g-1) and CNF-CS (187.2 F g-1). The assembled 1.2 V symmetric supercapacitor using CNF-CS/Co resulted in high energy density of 38.2 Wh.kg-1 along with electrochemical stability of 95.6% after 5000 charge-discharge cycles. Considering the facile preparation and results, the CNF-CS/Co nanocomposite could be well deserved for high performance supercapacitors.

Preparation of ZrO2 modified Al2O3 nano-sheets supported cobalt catalyst and its performance in Fischer-Tropsch synthesis

Abstract Al2O3 nano-sheet (Al2O3-CN) was synthesized under hydrothermal condition. The cobalt-based catalyst of 20% (mass fraction) was prepared by impregnation method and applied to Fischer-Tropsch synthesis. The Al2O3-CN (226 m2/g) and commercial alumina (Al2O3-C, 249 m2/g) have similar specific surface area, but Al2O3-CN has more narrow pore size distribution. Compared with Co/Al2O3-C catalyst, Co/Al2O3-CN catalyst showed higher reduction degree and more uniform cobalt particle size distribution after impregnation. Thus, Co/Al2O3-CN catalyst exhibited higher CO conversion and lower methane selectivity. In order to further improve the catalytic performance of Co/Al2O3-CN, Al2O3-CN was modified with ZrO2. The characterization results showed that with the increase of ZrO2, the specific surface of Al2O3-CN did not change significantly, and the pore volume and pore diameter increased. The cobalt particle size decreased and the number of active sites increased. Under the same reaction conditions, the CO conversion rate of catalysts modifield by ZrO2 was further improved and selectivity of methane was decreased.