Under the backdrop of“Carbon Peak and Carbon Neutrality”(dual carbon)goal in China,the methane-carbon dioxide reforming reaction has attracted considerable attention due to its environmental benefits of converting t...Under the backdrop of“Carbon Peak and Carbon Neutrality”(dual carbon)goal in China,the methane-carbon dioxide reforming reaction has attracted considerable attention due to its environmental benefits of converting two greenhouse gases(methane and carbon dioxide)into syngas and its promising industrial applications.Nickel(Ni)-based catalysts,with high catalytic activity,low cost,and abundant resources,are considered ideal candidates for industrial applications.In this article,three reaction kinetic models were briefly introduced,namely the Power-Law(PL)model,the Eley-Rideal(ER)model,and the Langmuir-Hinshelwood-Hougen-Watson(LHHW)model.Based on the LHHW model,the reaction kinetics and mechanisms of different catalytic systems were systematically discussed,including the properties of supports,the doping of noble metals and transition metals,the role of promoters,and the influence of the geometric and electronic structures of Ni on the reaction mechanism.Furthermore,the kinetics of carbon deposition and elimination on various catalysts were analyzed.Based on the reaction rate expressions for carbon elimination,the reasons for the high activity of transition metal iron(Fe)-doped catalysts and core-shell structured catalysts in carbon elimination were explained.Based on the detailed collation and comparative analysis of the reaction mechanisms and kinetic characteristics across diverse Ni-based catalytic systems,a theoretical guidance for the designing of high-performance catalysts was provided in this work.展开更多
The electrochemical carbon dioxide reduction reaction(CO_(2)RR)can convert carbon dioxide into highvalue chemical substances and fuels by utilizing renewable electricity,which can not only complete the carbon cycle bu...The electrochemical carbon dioxide reduction reaction(CO_(2)RR)can convert carbon dioxide into highvalue chemical substances and fuels by utilizing renewable electricity,which can not only complete the carbon cycle but also effectively alleviate the problems of global warming and energy shortage.Nickelbased catalysts hold great promise and unbeatable merits for the electroreduction of carbon dioxide due to their excellent catalytic properties and activity.However,there were few review papers on the application of nickel-based catalysts in carbon dioxide electroreduction.This paper,therefore,presents the current status of research on nickel-based catalysts in carbon dioxide electroreduction categorized by different products.First,the advantages of CO_(2) electroreduction and nickel-based catalysts as well as the basic principles of CO_(2) electroreduction are presented;then the different types of nickel-based catalysts that can convert CO_(2) into different products are described in detail,including their syntheses,performances,and mechanisms.Finally,the common features of nickel-based catalysts towards different carbon dioxide electroreduction products,as well as the outlooks for the development of nickel-based catalysts will be summarized.It is highly expected that this review will help in the future research and development of nickel-based catalysts towards CO_(2) conversion.展开更多
Exploring efficient transition-metal-based electrocatalysts is critical for the wide application of electrochemical hydrogen generation technology.Although the phase displays prominent influence on their performance,i...Exploring efficient transition-metal-based electrocatalysts is critical for the wide application of electrochemical hydrogen generation technology.Although the phase displays prominent influence on their performance,it remains a major challenge to achieve phase regulation in the same synthesis method and elucidate the intrinsic relationship between the phase and activity.Herein,we developed a sulfur induced electrodeposition strategy to achieve the precise phase regulation of nickel-based materials from Ni(OH)_(2)to Ni and Ni_(3)S_(2).S atoms can be introduced into Ni and Ni(OH)_(2)due to sulfur inducement,and the S proportion is finely controlled via changing the deposition parameters.Importantly,the obtained S-Ni catalyst displays enhanced hydrogen evolution activity with an ultralow overpotential of 27 mV at 10 mA cm^(-2),which is superior to the S-Ni(OH)_(2),Ni_(3)S_(2),and even Pt/C.Density functional theory(DFT)calculations disclose the S-Ni catalyst exhibits optimal charge state and local coordination,remarkably optimizing the water adsorption and Ni-H^(*)binding energy.This work provides new insights into phase regulation in electrodeposition and an understanding of the intrinsic relationship between phase and activity.展开更多
The nickel-based catalysts were prepared by the sol-gel method and used for the CH4 reforming with CO2. The effects of the sol-gel method on the specific surface area, catalytic activity, desorption, and reduction per...The nickel-based catalysts were prepared by the sol-gel method and used for the CH4 reforming with CO2. The effects of the sol-gel method on the specific surface area, catalytic activity, desorption, and reduction performances of catalysts were investigated with BET, TPR, and TPD. Compared with the catalyst prepared by the impregnation method, the results indicated that the catalysts prepared by the sol-gel method had larger specific surface area, showing higher catalytic activities and exhibiting perfect desorption and reduction performances. In addition, the modification effects of adding La were studied, and it was found that the 0.75NLBT catalyst constituted of 5wt.%Ni-0.75wt.%La was optimal.展开更多
A plasma-assisted method was employed to prepare Ni/γ-All2O3 catalyst for carbon dioxide reforming of methane reaction. The novel catalyst possessed higher activity and better coke-suppression performance than those ...A plasma-assisted method was employed to prepare Ni/γ-All2O3 catalyst for carbon dioxide reforming of methane reaction. The novel catalyst possessed higher activity and better coke-suppression performance than those of the conventional calcination catalyst. To achieve the same CH4 conversion, the conventional catalyst needed higher reaction temperature, about 50 ℃ higher than that of the N2 plasma-treated catalyst. After the evaluation test, the deactivation rate of the novel catalyst was 1.7%, compared with 15.2% for the conventional catalyst. Different from the characterization results of the calcined catalyst, a smaller average pore diameter and a higher specific surface area were obtained for the plasma-treated catalyst. The variations of the reduction peak temperatures and areas indicated that the catalyst reducibility was promoted by plasma assistance. The dispersion of nickel was also remarkably improved, which was helpful for controlling the ensemble size of metal atoms on the catalyst surface. The modification effect of plasma- assisted preparation on the surface property of alumina supported catalyst was speculated to account for the concentration increase of absorbed CO2. An enhancement of CO2 adsorption was propitious to the inhibition of carbon formation. The coke amount deposited on plasma treated catalyst was much smaller than that on the conventional catalyst.展开更多
Decomposition of methane in the presence of coprecipitated nickel-basedcatalysts to produce carbon fibers was investigated. The reaction was studied in the temperaturerange of 773 K to 1073 K. At 1023 K, the catalytic...Decomposition of methane in the presence of coprecipitated nickel-basedcatalysts to produce carbon fibers was investigated. The reaction was studied in the temperaturerange of 773 K to 1073 K. At 1023 K, the catalytic activities of three catalysts kept high at theinitial period and then decreased with the reaction time. The lifetimes of Ni-Cu-Al and Ni-La-Alcatalysts are longer than that of Ni-Al catalyst. With three catalysts, the yield of carbon fiberswas very low at 773 K. The yield of carbon fibers for Ni-La-Al catalyst was more than those forNi-Al and Ni-Cu-Al catalysts. For Ni-La-Al catalyst, the elevation of temperature from 873 K up to1073 K led gradually to an increase in the yield of carbon fibers. XRD studies on the Ni-La-Alcatalyst indicate that La_2NiO_4 was formed. The formation of La_2NiO_4 is responsible for theincrease in the catalytic lifetime and the yield of carbon fibers synthesized on Ni-La-Al at773-1073 K. Carbon fibers synthesized on Ni-Al catalyst are thin, long carbon nanotubes. There arebamboo-shaped carbon fibers synthesized on Ni-Cu-Al catalyst. Carbon fibers synthesized on Ni-La-Alcatalyst have large hollow core, thin wall and good graphitization.展开更多
Direct decomposition of methane was carried out using a fixed-bed reactor at 700 ℃ for the production of COx-free hydrogen and carbon nanofibers. The catalytic performance of NiO-M/SiO2 catalysts （where M=AgO, CoO, ...Direct decomposition of methane was carried out using a fixed-bed reactor at 700 ℃ for the production of COx-free hydrogen and carbon nanofibers. The catalytic performance of NiO-M/SiO2 catalysts （where M=AgO, CoO, CuO, FeO, MnOx and MoO） in methane decomposition was investigated. The experimental results indicate that among the tested catalysts, NiO/SiO2 promoted with CuO give the highest hydrogen yield. In addition, the examination of the most suitable catalyst support, including Al2O3, CeO2, La2O3, SiO2, and TiO2, shows that the decomposition of methane over NiO-CuO favors SiOx support. Furthermore, the optimum ratio of NiO to CuO on SiO2 support for methane decomposition was determined. The experimental results show that the optimum weight ratio of NiO to CuO fell at 8：2 （w/w） since the highest yield of hydrogen was obtained over this catalyst.展开更多
The excessive use of nonrenewable energy has brought about serious greenhouse effect.Converting CO_(2) into high-value-added chemicals is undoubtedly the best choice to solve energy problems.Due to the excellent cost-...The excessive use of nonrenewable energy has brought about serious greenhouse effect.Converting CO_(2) into high-value-added chemicals is undoubtedly the best choice to solve energy problems.Due to the excellent cost-effectiveness and dramatic catalytic performance,nickel-based catalysts have been considered as the most promising candidates for the electrocatalytic CO_(2) reduction reaction(eCO_(2)RR).In this work,the electrocatalytic reduction mechanism of CO_(2) over Ni-based materials is reviewed.The strategies to improve the eCO_(2)RR performance are emphasized.Moreover,the research on Ni-based materials for syngas generation is briefly summarized.Finally,the prospects of nickel-based materials in the eCO_(2)RR are provided with the hope of improving transition-metal-based electrocatalysts for eCO_(2)RR in the future.展开更多
Nickel-based catalyst[N,N]NiBr2,in which[N,N]stands for N-(2,6-diisopropylphenyl)pyridine-2-carboxaldimine,shows high activity for ethylene polymerization in the presence of organoaluminum compounds under high ethylen...Nickel-based catalyst[N,N]NiBr2,in which[N,N]stands for N-(2,6-diisopropylphenyl)pyridine-2-carboxaldimine,shows high activity for ethylene polymerization in the presence of organoaluminum compounds under high ethylene pressure to yield polyethylene characteristic of low molecular weight and highly branched chains.Toluene as the solvent is more in favor of catalyst activity,higher molecular weight and branched chains in polyethylene structure as compared to hexane solvent.展开更多
The influence of the synthesis method parameters used to prepare nickel-based catalysts on the catalytic performance for the glycerol steam reforming reaction was studied.A series of Al2O3-supported Ni catalysts were ...The influence of the synthesis method parameters used to prepare nickel-based catalysts on the catalytic performance for the glycerol steam reforming reaction was studied.A series of Al2O3-supported Ni catalysts were synthesized,with nickel loading of 8 wt%,using the incipient wetness,wet impregnation,and modified equilibrium deposition filtration methods.The catalysts＇ surface and bulk properties were determined by inductively coupled plasma（ICP）,N2 adsorption-desorption isotherms（BET）,X-ray diffraction（XRD）,scanning electron microscopy（SEM）,transmission electron microscopy（TEM）,and temperature-programmed reduction（TPR）.Used catalysts were characterized by techniques such as elemental analysis and SEM in order to determine the level of carbon that was deposited and catalyst morphology.The results indicated that the synthesis method affected the textural,structural and surface properties of the catalysts,differentiating the dispersion and the kind of nickel species on alumina＇s surface.The formation of nickel aluminate phases was confirmed by the XRD and TPR analysis and the β-peak of the Ni/Al-edf catalyst was higher than in the other two catalysts,indicating that the nickel aluminate species of this catalyst were more reducible.Both Ni/Al-wet and Ni/Al-edf catalysts showed increasing CO2 selectivities and approximately constant CO selectivities for temperatures above 550℃,indicating that these catalysts successfully catalyze the water gas shift reaction.It was also confirmed that the Ni/Al-edf catalyst had the highest values for glycerol to gaseous products conversion,hydrogen yield,allyl alcohol,acetaldehyde,and acetic acid selectivities at 650℃ and the lowest carbon deposition of the catalysts tested.The correlation of the catalysts＇ structural properties,dispersion and reducibility with catalytic performance reveals that the EDF method can provide catalysts with higher specific surface area and active phase＇s dispersion,that are easier to reduce,more active and selective to hydrogen production,and more resistant to carbon deposition.展开更多
The continuous rise in CO_(2)emissions from fossil fuel consumption has intensified the search for alternative clean energy sources.Hydrogen produced from renewable sources like ethanol offers a promising alternative ...The continuous rise in CO_(2)emissions from fossil fuel consumption has intensified the search for alternative clean energy sources.Hydrogen produced from renewable sources like ethanol offers a promising alternative to fossil fuels,mitigating CO_(2)emissions.This study investigates the kinetics of hydrogen production via ethanol steam reforming using a nickel-based catalyst,specifically the Ar-401 catalyst.Characterization techniques,including scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy,transmission electron microscopy,Brunauer–Emmett–Teller method,temperature-programmed reduction,and powder X-ray diffraction,were used to analyze the catalyst properties.Under optimal conditions of 973 K,atmospheric pressure,and a steam-to-ethanol ratio of 9,we achieved 100%ethanol conversion,74.8%hydrogen selectivity,and 85%hydrogen yield.Kinetic experiments were conducted under kinetically controlled conditions,examining the effects of temperature(473–673 K)and weight hourly space velocity ranging from 1 to 15(g·h/mol).A power law kinetic model was developed,yielding an activation energy of 11.17 kJ/mol and a reaction order of 0.46,with an absolute average deviation of 3.23%between predicted and experimental rates.This study provides key insights into the reaction mechanisms and highlights the effectiveness of the nickel-based catalyst,providing valuable insights for the design of efficient chemical reactors for sustainable hydrogen production.展开更多
Black nickel coatings have emerged as a research hotspot in materials science due to their excellent performance and broad application prospects.In this study,nickel-based black coatings were fabricated on low-carbon ...Black nickel coatings have emerged as a research hotspot in materials science due to their excellent performance and broad application prospects.In this study,nickel-based black coatings were fabricated on low-carbon steel substrates via photo-assisted electrodeposition.A systematic investigation was conducted on the effects of cerium ion concentration and nano-ceria(CeO_(2))particle content in the electrolyte on the coating properties,along with an analysis of the temporal evolution of coating’s corrosion resistance.When the cerium ion concentration in the electrolyte was 0.05 mol/L,the coating exhibited a uniform black appearance with a light absorption rate of 95%,an emissivity of 0.87,maximum impedance,and the lowest corrosion tendency,demonstrating optimal comprehensive performance.The coating prepared with a nano-ceria concentration of 6 g/L in the electrolyte exhibited an emissivity of 0.9,achieved a 5B adhesion grade(ASTM D3359-09),and demonstrated a one-order-of-magnitude reduction in corrosion current density compared to coatings fabricated without nano-ceria in the electrolyte.With prolonged storage time,the coating's impedance slightly increased,leading to improved corrosion resistance.展开更多
Nickel-based single-crystal superalloy DD98M is widely used in high-temperature components such as aero-engines and gas turbines.Since it has only one crystal grain,the theory of slip deformation along the grain bound...Nickel-based single-crystal superalloy DD98M is widely used in high-temperature components such as aero-engines and gas turbines.Since it has only one crystal grain,the theory of slip deformation along the grain boundary of polycrystalline material is not suitable for the machining of a single crystal part.Therefore,micro-drilling of nickel-based single crystal superalloy still faces problems such as unclear cutting formation me-chanism and unclear surface/subsurface damage mechanism.In this paper,the formation mechanism and morphological characteristics of chips and burrs were studied by a single-factor experiment,and the plastic deformation rule and damage mechanism were investigated,combined with the changes of subsurface structure and grain type.Finally,the influence of the law and reason of tool wear condition on the hole wall and the drilled subsurface is analyzed.The experimental results indicate that drill chips mainly exhibit three morphologies.Their free surfaces feature a serrated appearance,while the contact surfaces are smooth.The entrance burrs are mainly flanging burrs.With the increase of spindle speed,the burr height decreases from 49.38 to 9.39μm.As the feed speed increases,the burr height increases from 6.50 to 63.87μm.The drilled subsurface can be divided into a white layer region,a plastic deformation region,and the matrix according to the microstructural change.As the depth from the machined surface increases,the degree of plastic deformation of the material decreases,the grain size gradually reduces,and the dislocation density decreases.Stacking fault and twinning mostly occur in the high-plastic deformation region,and recrystallization occurs on the machined surface.As the drilling length increases,the degree of tool wear increases,and the adhesion and ablation area on the hole wall surface increase.Moreover,the thickness of the white layer increases from 0 to 8.75μm,and the thickness of the plastic deformation layer increases from 1.28 to 11.31μm.The study has significant theoretical and practical implications for the efficient and low-damage machining of micro-holes in the nickel-based single crystal superalloy.展开更多
A multistage solution treatment process was applied for nickel-based single crystal superalloys,complemented by various aging durations and cooling rates.The microstructure was characterized by scanning electron micro...A multistage solution treatment process was applied for nickel-based single crystal superalloys,complemented by various aging durations and cooling rates.The microstructure was characterized by scanning electron microscopy(SEM)to observe the γ'phase.Additionally,phase field simulations were conducted to model the growth ofγ'precipitates during aging and analyze their morphological evolution.The experimental results demonstrated that the multistage solution treatment effectively eliminated eutectic phases and carbides.Moreover,samples aged for 10 min exhibited larger and more rectangularγ'precipitates compared with those aged for 5 min.Notably,secondary γ'precipitates were observed in samples subjected to water cooling.Two indices for quantifying rectangularization were proposed and successfully applied.Based on the simulation results,lattice mismatch induced coherency stresses and elevated stress triaxiality along the <111> direction contributed to the rectangularization of theγ'phase.展开更多
The development of cost-effective and energy-efficient anode materials is essential for the advancement of industrial water electrolysis.Herein,we report a rapid,ambient-temperature method to prepare largearea nickel ...The development of cost-effective and energy-efficient anode materials is essential for the advancement of industrial water electrolysis.Herein,we report a rapid,ambient-temperature method to prepare largearea nickel mesh electrodes(SFN/NM)via surface functionalization completed within 3 min,without relying on thermal treatments or noble metals.The as-prepared electrodes achieve a high current density of 100 m A/cm^(2)at an overpotential of just 300 m V in 6 mol/L KOH,and exhibit remarkable stability over1600 h of continuous operation.With comparable activity to commercial Raney nickel yet significantly lower processing and material costs(reduced by 50%-70%),this approach provides a practical solution for low-energy water splitting.Beyond its industrial relevance,the strategy offers a scalable model for engineering high-performance OER electrodes,inspiring future directions in electrocatalyst design.展开更多
The mechanical properties and oxidation resistance of two nickel-based superalloys with and without oxide dispersion strengthened(ODS)phases at different temperatures were studied.The microstructure was investigated b...The mechanical properties and oxidation resistance of two nickel-based superalloys with and without oxide dispersion strengthened(ODS)phases at different temperatures were studied.The microstructure was investigated by scanning electron microscopy(SEM),electron backscatter diffraction(EBSD),and transmission electron microscopy(TEM).The results show that the yield strength of the samples with and without ODS phases at room temperature is 1020 and 324 MPa,respectively.The yield strength model was constructed,and it is found that the contribution of grain boundary strengthening,dislocation strengthening and nanoparticle strengthening of nickel-based ODS superalloy exceeds 83%.As the temperature increases,grain boundary sliding and migration decrease the strength of sample but improve its ductility.Oxidation hinders the ductility of sample and intensifies its fracture,and the maximum elongation of nickel-based ODS superalloy at 800℃ is 47.3%.展开更多
For nickel-based superalloys with medium volume-fractionγʹphase(20%-40%),dual or multi-stage aging treatments are usually conducted to generate a microstructure containing the multimodal distri-bution ofγʹfor a bala...For nickel-based superalloys with medium volume-fractionγʹphase(20%-40%),dual or multi-stage aging treatments are usually conducted to generate a microstructure containing the multimodal distri-bution ofγʹfor a balance of strength and plasticity.In the present study,the microstructure and high-temperature properties of a novel cast nickel-based superalloy K4800 were investigated after being sub-jected to three heat treatments(HT)procedures,namely HT1:1180℃/4 h+1090℃/2 h+800℃/16 h,HT2:1180℃/4 h+1060℃/2 h+800℃/16 h and HT3:1180℃/4 h+800℃/16 h.It was found that the sub-solvus aging treatments at 1090 and 1060℃ precipitated sub-micron-sized(∼300 nm)primaryγʹphase which enhanced the ductility during 800℃ tensile(the total elongation of T1,T2,and T3 sam-ples were 6.75%,7.3%,and 3.25%,respectively)without evidently impairing the strength.After careful microstructure observation and deformation mechanism analysis,the enhancement of elongation was ra-tionalized that the precipitation of the sub-micron-sized primaryγʹphase decreased the volume-fraction and size of the nanometer-sizedγʹphase which was precipitated at 800℃,and simultaneously,pro-moted the dislocation movement by suppressing the non-planar slip.However,an excessive amount of the sub-micron-sized primaryγʹphase led to a faster ripening process of the nanometer-sizedγʹduring creep,which decreased the creep life at 800℃/430 MPa(T1:125 h,T2:199 h,and T3:198 h).Based on this,we monitored the number density of nanometer-sizedγʹphase coexisting with different amounts of largeγʹduring creep.An area fraction less than 7%of the sub-micron-sizedγʹphase was considered to have little detrimental effect on the creep life of K4800 alloy,which corresponded to a sub-solvus temperature range about 1080-1090℃.展开更多
The undeformed chip thickness and grinding force are key parameters for revealing the material removal mechanism in the grinding process.However,they are difficult to be well expressed due to the ununiformed protrusio...The undeformed chip thickness and grinding force are key parameters for revealing the material removal mechanism in the grinding process.However,they are difficult to be well expressed due to the ununiformed protrusion height and random position distribution of abrasive grains on the abrasive wheel surface.This study investigated the distribution of undeformed chip thickness and grinding force considering the non-uniform characteristics of abrasive wheel in the grinding of K4002 nickel-based superalloy.First,a novel grinding force model was established through a kinematic-geometric analysis and a grain-workpiece contact analysis.Then,a series of grinding experiments were conducted for verifying the model.The results indicate that the distribution of undeformed chip thickness is highly consistent with the Gaussian distribution formula.The increase in the grinding depth mainly leads to an increase in the average value of Gaussian distribution.On the contrary,the increase in the workpiece infeed speed or the decrease in the grinding speed mainly increases the standard deviation of Gaussian distribution.The average and maximum errors of the grinding force model are 4.9%and 14.6%respectively,indicating that the model is of high predication accuracy.展开更多
A new type of nickel-based single-crystal superalloy was subjected to creep performance test,microstructure observation,and composition analysis under the condition of 1100℃/140 MPa.The variation characteristics of t...A new type of nickel-based single-crystal superalloy was subjected to creep performance test,microstructure observation,and composition analysis under the condition of 1100℃/140 MPa.The variation characteristics of the creep rate during the creep fracture process and the microstructure evolution before and after creep were investigated,thereby revealing the creep fracture mechanism of the new nickel-based single-crystal superalloy.The results indicate that the creep life of the alloy is 104.5 h,and the strain can reach 33.58%.The creep rate decreases first,then increases,and finally tends to be stable until fracture.At the initial stage of creep,the creep rate decreases first,then rises and finally decreases again with time.Furthermore,the creep fracture microstructure is composed of dimples and tearing edges without obvious slip planes.Oxides and recrystallized structures exist inside the fracture surface,and the voids inside the fracture are elongated and perpendicular to the stress axis,showing a fracture mechanism of microcrack accumulation.展开更多
Catalytic steam reforming is a promising route for tar conversion to high energy syngas in the process of biomass gasification. However, the catalyst deactivation caused by the deposition of residual carbon is still a...Catalytic steam reforming is a promising route for tar conversion to high energy syngas in the process of biomass gasification. However, the catalyst deactivation caused by the deposition of residual carbon is still a major challenge. In this paper, a modified Ni-based Ni-Co/Al2O3-CaO (Ni-Co/AC) catalyst and a conventional Ni/Al2O3 (Ni/A) catalyst were prepared and tested for tar catalytic removal in which toluene was selected as the model component. Experiments were conducted to reveal the influences of the reaction temperature and the ratio between steam to carbon on the toluene conversion and the hydrogen yield. The physicochemical properties of the modified Ni-based catalyst were determined by a series of characterization methods. The results indicated that the Ni-Co alloy was determined over the Ni-Co/AC catalyst. The doping of CaO and the presence of Ni-Co alloy promoted the performance of toluene catalytic dissociation over Ni-Co/AC catalyst compared with that over Ni/A catalyst. After testing in steam for 40 h, the carbon conversion over Ni-Co/AC maintained above 86% and its resistance to carbon deposition was superior to Ni/A catalyst.展开更多
基金Supported by Innovation Capability Support Program of Shaanxi(2024RS-CXTD-53,2024ZC-KJXX-096)the Key R&D Program of Shaanxi Province(2022QCY-LL-69)Xi’an Science and Technology Project(24GXFW0089)。
文摘Under the backdrop of“Carbon Peak and Carbon Neutrality”(dual carbon)goal in China,the methane-carbon dioxide reforming reaction has attracted considerable attention due to its environmental benefits of converting two greenhouse gases(methane and carbon dioxide)into syngas and its promising industrial applications.Nickel(Ni)-based catalysts,with high catalytic activity,low cost,and abundant resources,are considered ideal candidates for industrial applications.In this article,three reaction kinetic models were briefly introduced,namely the Power-Law(PL)model,the Eley-Rideal(ER)model,and the Langmuir-Hinshelwood-Hougen-Watson(LHHW)model.Based on the LHHW model,the reaction kinetics and mechanisms of different catalytic systems were systematically discussed,including the properties of supports,the doping of noble metals and transition metals,the role of promoters,and the influence of the geometric and electronic structures of Ni on the reaction mechanism.Furthermore,the kinetics of carbon deposition and elimination on various catalysts were analyzed.Based on the reaction rate expressions for carbon elimination,the reasons for the high activity of transition metal iron(Fe)-doped catalysts and core-shell structured catalysts in carbon elimination were explained.Based on the detailed collation and comparative analysis of the reaction mechanisms and kinetic characteristics across diverse Ni-based catalytic systems,a theoretical guidance for the designing of high-performance catalysts was provided in this work.
文摘The electrochemical carbon dioxide reduction reaction(CO_(2)RR)can convert carbon dioxide into highvalue chemical substances and fuels by utilizing renewable electricity,which can not only complete the carbon cycle but also effectively alleviate the problems of global warming and energy shortage.Nickelbased catalysts hold great promise and unbeatable merits for the electroreduction of carbon dioxide due to their excellent catalytic properties and activity.However,there were few review papers on the application of nickel-based catalysts in carbon dioxide electroreduction.This paper,therefore,presents the current status of research on nickel-based catalysts in carbon dioxide electroreduction categorized by different products.First,the advantages of CO_(2) electroreduction and nickel-based catalysts as well as the basic principles of CO_(2) electroreduction are presented;then the different types of nickel-based catalysts that can convert CO_(2) into different products are described in detail,including their syntheses,performances,and mechanisms.Finally,the common features of nickel-based catalysts towards different carbon dioxide electroreduction products,as well as the outlooks for the development of nickel-based catalysts will be summarized.It is highly expected that this review will help in the future research and development of nickel-based catalysts towards CO_(2) conversion.
基金supported by the National Natural Science Foundation of China(52271210,22179032,52171176)。
文摘Exploring efficient transition-metal-based electrocatalysts is critical for the wide application of electrochemical hydrogen generation technology.Although the phase displays prominent influence on their performance,it remains a major challenge to achieve phase regulation in the same synthesis method and elucidate the intrinsic relationship between the phase and activity.Herein,we developed a sulfur induced electrodeposition strategy to achieve the precise phase regulation of nickel-based materials from Ni(OH)_(2)to Ni and Ni_(3)S_(2).S atoms can be introduced into Ni and Ni(OH)_(2)due to sulfur inducement,and the S proportion is finely controlled via changing the deposition parameters.Importantly,the obtained S-Ni catalyst displays enhanced hydrogen evolution activity with an ultralow overpotential of 27 mV at 10 mA cm^(-2),which is superior to the S-Ni(OH)_(2),Ni_(3)S_(2),and even Pt/C.Density functional theory(DFT)calculations disclose the S-Ni catalyst exhibits optimal charge state and local coordination,remarkably optimizing the water adsorption and Ni-H^(*)binding energy.This work provides new insights into phase regulation in electrodeposition and an understanding of the intrinsic relationship between phase and activity.
基金supported by the Jiangxi Provincial Department of Education
文摘The nickel-based catalysts were prepared by the sol-gel method and used for the CH4 reforming with CO2. The effects of the sol-gel method on the specific surface area, catalytic activity, desorption, and reduction performances of catalysts were investigated with BET, TPR, and TPD. Compared with the catalyst prepared by the impregnation method, the results indicated that the catalysts prepared by the sol-gel method had larger specific surface area, showing higher catalytic activities and exhibiting perfect desorption and reduction performances. In addition, the modification effects of adding La were studied, and it was found that the 0.75NLBT catalyst constituted of 5wt.%Ni-0.75wt.%La was optimal.
文摘A plasma-assisted method was employed to prepare Ni/γ-All2O3 catalyst for carbon dioxide reforming of methane reaction. The novel catalyst possessed higher activity and better coke-suppression performance than those of the conventional calcination catalyst. To achieve the same CH4 conversion, the conventional catalyst needed higher reaction temperature, about 50 ℃ higher than that of the N2 plasma-treated catalyst. After the evaluation test, the deactivation rate of the novel catalyst was 1.7%, compared with 15.2% for the conventional catalyst. Different from the characterization results of the calcined catalyst, a smaller average pore diameter and a higher specific surface area were obtained for the plasma-treated catalyst. The variations of the reduction peak temperatures and areas indicated that the catalyst reducibility was promoted by plasma assistance. The dispersion of nickel was also remarkably improved, which was helpful for controlling the ensemble size of metal atoms on the catalyst surface. The modification effect of plasma- assisted preparation on the surface property of alumina supported catalyst was speculated to account for the concentration increase of absorbed CO2. An enhancement of CO2 adsorption was propitious to the inhibition of carbon formation. The coke amount deposited on plasma treated catalyst was much smaller than that on the conventional catalyst.
基金Supported by the National Natural Science Foundation of China (No. 20263003)Natural Science Foundation of Jiangxi province (No. 0250009)
文摘Decomposition of methane in the presence of coprecipitated nickel-basedcatalysts to produce carbon fibers was investigated. The reaction was studied in the temperaturerange of 773 K to 1073 K. At 1023 K, the catalytic activities of three catalysts kept high at theinitial period and then decreased with the reaction time. The lifetimes of Ni-Cu-Al and Ni-La-Alcatalysts are longer than that of Ni-Al catalyst. With three catalysts, the yield of carbon fiberswas very low at 773 K. The yield of carbon fibers for Ni-La-Al catalyst was more than those forNi-Al and Ni-Cu-Al catalysts. For Ni-La-Al catalyst, the elevation of temperature from 873 K up to1073 K led gradually to an increase in the yield of carbon fibers. XRD studies on the Ni-La-Alcatalyst indicate that La_2NiO_4 was formed. The formation of La_2NiO_4 is responsible for theincrease in the catalytic lifetime and the yield of carbon fibers synthesized on Ni-La-Al at773-1073 K. Carbon fibers synthesized on Ni-Al catalyst are thin, long carbon nanotubes. There arebamboo-shaped carbon fibers synthesized on Ni-Cu-Al catalyst. Carbon fibers synthesized on Ni-La-Alcatalyst have large hollow core, thin wall and good graphitization.
文摘Direct decomposition of methane was carried out using a fixed-bed reactor at 700 ℃ for the production of COx-free hydrogen and carbon nanofibers. The catalytic performance of NiO-M/SiO2 catalysts （where M=AgO, CoO, CuO, FeO, MnOx and MoO） in methane decomposition was investigated. The experimental results indicate that among the tested catalysts, NiO/SiO2 promoted with CuO give the highest hydrogen yield. In addition, the examination of the most suitable catalyst support, including Al2O3, CeO2, La2O3, SiO2, and TiO2, shows that the decomposition of methane over NiO-CuO favors SiOx support. Furthermore, the optimum ratio of NiO to CuO on SiO2 support for methane decomposition was determined. The experimental results show that the optimum weight ratio of NiO to CuO fell at 8：2 （w/w） since the highest yield of hydrogen was obtained over this catalyst.
基金support from the National Natural Science Foundation of China(52072389,52311530113)the Science and Technology Commission of Shanghai Municipality(22DZ1205600,20520760900)+2 种基金the Program of Shanghai Academic Research Leader(20XD1424300)for financial support.The authors also would like to express their gratitude to Tangshan Basic Research Funding Projects(23130210E),Hebei Province High-level Talent(Postdoctor)Funding Project(B2022003025)Key R&D projects of North China University of Science and Technology(ZD-ST-202301)Tangshan Talent Funding Project(A202202007)for their financial support.
文摘The excessive use of nonrenewable energy has brought about serious greenhouse effect.Converting CO_(2) into high-value-added chemicals is undoubtedly the best choice to solve energy problems.Due to the excellent cost-effectiveness and dramatic catalytic performance,nickel-based catalysts have been considered as the most promising candidates for the electrocatalytic CO_(2) reduction reaction(eCO_(2)RR).In this work,the electrocatalytic reduction mechanism of CO_(2) over Ni-based materials is reviewed.The strategies to improve the eCO_(2)RR performance are emphasized.Moreover,the research on Ni-based materials for syngas generation is briefly summarized.Finally,the prospects of nickel-based materials in the eCO_(2)RR are provided with the hope of improving transition-metal-based electrocatalysts for eCO_(2)RR in the future.
文摘Nickel-based catalyst[N,N]NiBr2,in which[N,N]stands for N-(2,6-diisopropylphenyl)pyridine-2-carboxaldimine,shows high activity for ethylene polymerization in the presence of organoaluminum compounds under high ethylene pressure to yield polyethylene characteristic of low molecular weight and highly branched chains.Toluene as the solvent is more in favor of catalyst activity,higher molecular weight and branched chains in polyethylene structure as compared to hexane solvent.
基金Financial support by the program THALIS implemented within the framework of Education and Lifelong Learning Operational Programmeco-financed by the Hellenic Ministry of Education,Lifelong Learning and Religious Affairs and the European Social Fund,for the project 'Production of Energy Carriers from Biomass by Productsfinancial support provided by the Committee of the Special Account for Research Funds of the Technological Educational Institute of Western Macedonia(ELKE,TEIWM)
文摘The influence of the synthesis method parameters used to prepare nickel-based catalysts on the catalytic performance for the glycerol steam reforming reaction was studied.A series of Al2O3-supported Ni catalysts were synthesized,with nickel loading of 8 wt%,using the incipient wetness,wet impregnation,and modified equilibrium deposition filtration methods.The catalysts＇ surface and bulk properties were determined by inductively coupled plasma（ICP）,N2 adsorption-desorption isotherms（BET）,X-ray diffraction（XRD）,scanning electron microscopy（SEM）,transmission electron microscopy（TEM）,and temperature-programmed reduction（TPR）.Used catalysts were characterized by techniques such as elemental analysis and SEM in order to determine the level of carbon that was deposited and catalyst morphology.The results indicated that the synthesis method affected the textural,structural and surface properties of the catalysts,differentiating the dispersion and the kind of nickel species on alumina＇s surface.The formation of nickel aluminate phases was confirmed by the XRD and TPR analysis and the β-peak of the Ni/Al-edf catalyst was higher than in the other two catalysts,indicating that the nickel aluminate species of this catalyst were more reducible.Both Ni/Al-wet and Ni/Al-edf catalysts showed increasing CO2 selectivities and approximately constant CO selectivities for temperatures above 550℃,indicating that these catalysts successfully catalyze the water gas shift reaction.It was also confirmed that the Ni/Al-edf catalyst had the highest values for glycerol to gaseous products conversion,hydrogen yield,allyl alcohol,acetaldehyde,and acetic acid selectivities at 650℃ and the lowest carbon deposition of the catalysts tested.The correlation of the catalysts＇ structural properties,dispersion and reducibility with catalytic performance reveals that the EDF method can provide catalysts with higher specific surface area and active phase＇s dispersion,that are easier to reduce,more active and selective to hydrogen production,and more resistant to carbon deposition.
基金supports of the Mitacs Accelerate(IT29592),Proteum Hydrogen Technology,Natural Sciences and Engineering Research Council of Canada(NSERC DG:RGPIN-2024-04760)the Canada Foundation for Innovation(CFI JELF:37758)are gratefully acknowledged。
文摘The continuous rise in CO_(2)emissions from fossil fuel consumption has intensified the search for alternative clean energy sources.Hydrogen produced from renewable sources like ethanol offers a promising alternative to fossil fuels,mitigating CO_(2)emissions.This study investigates the kinetics of hydrogen production via ethanol steam reforming using a nickel-based catalyst,specifically the Ar-401 catalyst.Characterization techniques,including scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy,transmission electron microscopy,Brunauer–Emmett–Teller method,temperature-programmed reduction,and powder X-ray diffraction,were used to analyze the catalyst properties.Under optimal conditions of 973 K,atmospheric pressure,and a steam-to-ethanol ratio of 9,we achieved 100%ethanol conversion,74.8%hydrogen selectivity,and 85%hydrogen yield.Kinetic experiments were conducted under kinetically controlled conditions,examining the effects of temperature(473–673 K)and weight hourly space velocity ranging from 1 to 15(g·h/mol).A power law kinetic model was developed,yielding an activation energy of 11.17 kJ/mol and a reaction order of 0.46,with an absolute average deviation of 3.23%between predicted and experimental rates.This study provides key insights into the reaction mechanisms and highlights the effectiveness of the nickel-based catalyst,providing valuable insights for the design of efficient chemical reactors for sustainable hydrogen production.
文摘Black nickel coatings have emerged as a research hotspot in materials science due to their excellent performance and broad application prospects.In this study,nickel-based black coatings were fabricated on low-carbon steel substrates via photo-assisted electrodeposition.A systematic investigation was conducted on the effects of cerium ion concentration and nano-ceria(CeO_(2))particle content in the electrolyte on the coating properties,along with an analysis of the temporal evolution of coating’s corrosion resistance.When the cerium ion concentration in the electrolyte was 0.05 mol/L,the coating exhibited a uniform black appearance with a light absorption rate of 95%,an emissivity of 0.87,maximum impedance,and the lowest corrosion tendency,demonstrating optimal comprehensive performance.The coating prepared with a nano-ceria concentration of 6 g/L in the electrolyte exhibited an emissivity of 0.9,achieved a 5B adhesion grade(ASTM D3359-09),and demonstrated a one-order-of-magnitude reduction in corrosion current density compared to coatings fabricated without nano-ceria in the electrolyte.With prolonged storage time,the coating's impedance slightly increased,leading to improved corrosion resistance.
基金Supported by National Natural Science Foundation of China(Grant Nos.52475433,52305453)Hebei Provincial Natural Science Foundation(Grant No.E2022501004)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.2023GFYD002)Shijiazhuang Municipal Science and Technology Plan Project(Grant No.241790747A).
文摘Nickel-based single-crystal superalloy DD98M is widely used in high-temperature components such as aero-engines and gas turbines.Since it has only one crystal grain,the theory of slip deformation along the grain boundary of polycrystalline material is not suitable for the machining of a single crystal part.Therefore,micro-drilling of nickel-based single crystal superalloy still faces problems such as unclear cutting formation me-chanism and unclear surface/subsurface damage mechanism.In this paper,the formation mechanism and morphological characteristics of chips and burrs were studied by a single-factor experiment,and the plastic deformation rule and damage mechanism were investigated,combined with the changes of subsurface structure and grain type.Finally,the influence of the law and reason of tool wear condition on the hole wall and the drilled subsurface is analyzed.The experimental results indicate that drill chips mainly exhibit three morphologies.Their free surfaces feature a serrated appearance,while the contact surfaces are smooth.The entrance burrs are mainly flanging burrs.With the increase of spindle speed,the burr height decreases from 49.38 to 9.39μm.As the feed speed increases,the burr height increases from 6.50 to 63.87μm.The drilled subsurface can be divided into a white layer region,a plastic deformation region,and the matrix according to the microstructural change.As the depth from the machined surface increases,the degree of plastic deformation of the material decreases,the grain size gradually reduces,and the dislocation density decreases.Stacking fault and twinning mostly occur in the high-plastic deformation region,and recrystallization occurs on the machined surface.As the drilling length increases,the degree of tool wear increases,and the adhesion and ablation area on the hole wall surface increase.Moreover,the thickness of the white layer increases from 0 to 8.75μm,and the thickness of the plastic deformation layer increases from 1.28 to 11.31μm.The study has significant theoretical and practical implications for the efficient and low-damage machining of micro-holes in the nickel-based single crystal superalloy.
基金supported by the Stable Support Project and the Major National Science and Technology Project,China(Nos.2017-Ⅶ-0008-0101,2017-Ⅵ-0003-0073)。
文摘A multistage solution treatment process was applied for nickel-based single crystal superalloys,complemented by various aging durations and cooling rates.The microstructure was characterized by scanning electron microscopy(SEM)to observe the γ'phase.Additionally,phase field simulations were conducted to model the growth ofγ'precipitates during aging and analyze their morphological evolution.The experimental results demonstrated that the multistage solution treatment effectively eliminated eutectic phases and carbides.Moreover,samples aged for 10 min exhibited larger and more rectangularγ'precipitates compared with those aged for 5 min.Notably,secondary γ'precipitates were observed in samples subjected to water cooling.Two indices for quantifying rectangularization were proposed and successfully applied.Based on the simulation results,lattice mismatch induced coherency stresses and elevated stress triaxiality along the <111> direction contributed to the rectangularization of theγ'phase.
基金supported by the National Natural Science Foundation of China(Nos.52473299,52201009,52301013 and52231008)the Key Research and Development Program of Hainan Province(No.ZDYF2024GXJS006)+1 种基金International Science&Technology Cooperation Program of Hainan Province(No.GHYF2023007)the Education Department of Hainan Province(No.Hnky2024ZD-2)。
文摘The development of cost-effective and energy-efficient anode materials is essential for the advancement of industrial water electrolysis.Herein,we report a rapid,ambient-temperature method to prepare largearea nickel mesh electrodes(SFN/NM)via surface functionalization completed within 3 min,without relying on thermal treatments or noble metals.The as-prepared electrodes achieve a high current density of 100 m A/cm^(2)at an overpotential of just 300 m V in 6 mol/L KOH,and exhibit remarkable stability over1600 h of continuous operation.With comparable activity to commercial Raney nickel yet significantly lower processing and material costs(reduced by 50%-70%),this approach provides a practical solution for low-energy water splitting.Beyond its industrial relevance,the strategy offers a scalable model for engineering high-performance OER electrodes,inspiring future directions in electrocatalyst design.
基金supported by the National Natural Science Foundation of China(No.52271177)Leading Talents Project of Scientific and Technological Innovation in Hunan Province,China(No.2021RC4036)+1 种基金the Natural Science Foundation of Hunan Province,China(Nos.2023JJ50172,2020JJ6069)State Key Laboratory of Materials Processing and Die&Mould Technology,Huazhong University of Science and Technology,China。
文摘The mechanical properties and oxidation resistance of two nickel-based superalloys with and without oxide dispersion strengthened(ODS)phases at different temperatures were studied.The microstructure was investigated by scanning electron microscopy(SEM),electron backscatter diffraction(EBSD),and transmission electron microscopy(TEM).The results show that the yield strength of the samples with and without ODS phases at room temperature is 1020 and 324 MPa,respectively.The yield strength model was constructed,and it is found that the contribution of grain boundary strengthening,dislocation strengthening and nanoparticle strengthening of nickel-based ODS superalloy exceeds 83%.As the temperature increases,grain boundary sliding and migration decrease the strength of sample but improve its ductility.Oxidation hinders the ductility of sample and intensifies its fracture,and the maximum elongation of nickel-based ODS superalloy at 800℃ is 47.3%.
文摘For nickel-based superalloys with medium volume-fractionγʹphase(20%-40%),dual or multi-stage aging treatments are usually conducted to generate a microstructure containing the multimodal distri-bution ofγʹfor a balance of strength and plasticity.In the present study,the microstructure and high-temperature properties of a novel cast nickel-based superalloy K4800 were investigated after being sub-jected to three heat treatments(HT)procedures,namely HT1:1180℃/4 h+1090℃/2 h+800℃/16 h,HT2:1180℃/4 h+1060℃/2 h+800℃/16 h and HT3:1180℃/4 h+800℃/16 h.It was found that the sub-solvus aging treatments at 1090 and 1060℃ precipitated sub-micron-sized(∼300 nm)primaryγʹphase which enhanced the ductility during 800℃ tensile(the total elongation of T1,T2,and T3 sam-ples were 6.75%,7.3%,and 3.25%,respectively)without evidently impairing the strength.After careful microstructure observation and deformation mechanism analysis,the enhancement of elongation was ra-tionalized that the precipitation of the sub-micron-sized primaryγʹphase decreased the volume-fraction and size of the nanometer-sizedγʹphase which was precipitated at 800℃,and simultaneously,pro-moted the dislocation movement by suppressing the non-planar slip.However,an excessive amount of the sub-micron-sized primaryγʹphase led to a faster ripening process of the nanometer-sizedγʹduring creep,which decreased the creep life at 800℃/430 MPa(T1:125 h,T2:199 h,and T3:198 h).Based on this,we monitored the number density of nanometer-sizedγʹphase coexisting with different amounts of largeγʹduring creep.An area fraction less than 7%of the sub-micron-sizedγʹphase was considered to have little detrimental effect on the creep life of K4800 alloy,which corresponded to a sub-solvus temperature range about 1080-1090℃.
基金financially supported by the National Natural Science Foundation of China(Nos.92160301,92060203,52175415 and 52205475)the Science Center for Gas Turbine Project(Nos.P2022-AB-Ⅳ-002-001 and P2023-B-Ⅳ-003-001)+3 种基金the Jiangsu Key Laboratory of Precision and Micro-Manufacturing Technology(No.JSKL2223K01)the Natural Science Foundation of Jiangsu Province(No.BK20210295)the Superior Postdoctoral Project of Jiangsu Province(No.2022ZB215)the Henan Science and Technology Public Relations Project(No.212102210445).
文摘The undeformed chip thickness and grinding force are key parameters for revealing the material removal mechanism in the grinding process.However,they are difficult to be well expressed due to the ununiformed protrusion height and random position distribution of abrasive grains on the abrasive wheel surface.This study investigated the distribution of undeformed chip thickness and grinding force considering the non-uniform characteristics of abrasive wheel in the grinding of K4002 nickel-based superalloy.First,a novel grinding force model was established through a kinematic-geometric analysis and a grain-workpiece contact analysis.Then,a series of grinding experiments were conducted for verifying the model.The results indicate that the distribution of undeformed chip thickness is highly consistent with the Gaussian distribution formula.The increase in the grinding depth mainly leads to an increase in the average value of Gaussian distribution.On the contrary,the increase in the workpiece infeed speed or the decrease in the grinding speed mainly increases the standard deviation of Gaussian distribution.The average and maximum errors of the grinding force model are 4.9%and 14.6%respectively,indicating that the model is of high predication accuracy.
基金China Postdoctoral Science Foundation General Project(2024M760034)Postdoctoral Research Programs of Anhui Province(2024A774)。
文摘A new type of nickel-based single-crystal superalloy was subjected to creep performance test,microstructure observation,and composition analysis under the condition of 1100℃/140 MPa.The variation characteristics of the creep rate during the creep fracture process and the microstructure evolution before and after creep were investigated,thereby revealing the creep fracture mechanism of the new nickel-based single-crystal superalloy.The results indicate that the creep life of the alloy is 104.5 h,and the strain can reach 33.58%.The creep rate decreases first,then increases,and finally tends to be stable until fracture.At the initial stage of creep,the creep rate decreases first,then rises and finally decreases again with time.Furthermore,the creep fracture microstructure is composed of dimples and tearing edges without obvious slip planes.Oxides and recrystallized structures exist inside the fracture surface,and the voids inside the fracture are elongated and perpendicular to the stress axis,showing a fracture mechanism of microcrack accumulation.
基金financially supported by the National Nature Science Foundation of China(Grant Nos.51922040 and 51821004)the Fok Ying Tung Education Foundation(Grant No.161051)the Fundamental Research Funds for the Central Universities(Nos.2018ZD08 and 2020DF01).
文摘Catalytic steam reforming is a promising route for tar conversion to high energy syngas in the process of biomass gasification. However, the catalyst deactivation caused by the deposition of residual carbon is still a major challenge. In this paper, a modified Ni-based Ni-Co/Al2O3-CaO (Ni-Co/AC) catalyst and a conventional Ni/Al2O3 (Ni/A) catalyst were prepared and tested for tar catalytic removal in which toluene was selected as the model component. Experiments were conducted to reveal the influences of the reaction temperature and the ratio between steam to carbon on the toluene conversion and the hydrogen yield. The physicochemical properties of the modified Ni-based catalyst were determined by a series of characterization methods. The results indicated that the Ni-Co alloy was determined over the Ni-Co/AC catalyst. The doping of CaO and the presence of Ni-Co alloy promoted the performance of toluene catalytic dissociation over Ni-Co/AC catalyst compared with that over Ni/A catalyst. After testing in steam for 40 h, the carbon conversion over Ni-Co/AC maintained above 86% and its resistance to carbon deposition was superior to Ni/A catalyst.
