In an electrocatalyst with a heterointerface structure,the different interfaces can efficiently adjust the catalyst’s conductivity and electron arrangement,thereby enhancing the activity of the electrocatalyst.Ultrat...In an electrocatalyst with a heterointerface structure,the different interfaces can efficiently adjust the catalyst’s conductivity and electron arrangement,thereby enhancing the activity of the electrocatalyst.Ultrathin and smaller Ni Fe LDH was successfully constructed on the surface of SnOnanosheet supported NF by layer by layer assembly,and exhibits lower overpotential of 234 mV at a current density of 10 m A cm,which only increases by 6.4%even at a high current density of 100 mA cm.The excellent OER activity of catalyst is attributed to the contribution of the semiconductor SnOelectron transport layer.Through experiments and characterization,3d structure SnOnanosheets control the growth of ultra-thin nickel-iron,the hierarchical interface between SnOand Ni Fe LDH can change the electron arrangement around the iron and nickel active centers at the interface,resulting the valence states of iron slightly increased and Nicontent increased.The result will promote the oxidation of water.Meanwhile,the SnOsemiconductor as electron transport layer is conducive to trapping electrons generated in oxidation reaction,promoting electrons transferring from the Ni Fe LDH active center to the Ni substrate more quickly,and enhance the activity of Ni Fe LDH.It also shows excellent activity in an electrolyte solution containing 0.5 M methanol and 1 M KOH,and only 1.396 V(vs.RHE)is required to drive a current density of 10 mA cm.展开更多
A novel SnO2-based gas anode was developed for aluminum electrolysis in molten cryolite at 850 ＆#176;C to reduce energy consumption and decrease CO2 emissions. Hydrogen was introduced into the anode, participating in...A novel SnO2-based gas anode was developed for aluminum electrolysis in molten cryolite at 850 ＆#176;C to reduce energy consumption and decrease CO2 emissions. Hydrogen was introduced into the anode, participating in the anode reaction. Carbon and aluminum were used as the cathode and reference electrodes, respectively. Cyclic voltammetry was applied in the cell to investigate the electrochemical behavior of oxygen ion on platinum and SnO2-based materials. The potential for oxygen evolution on these electrode materials was determined. Then, galvanostatic electrolysis was performed on the gas anode, showing a significant depolarization effect （a decrease of ~0.8 V of the anode potential） after the introduction of hydrogen, compared with no gas introduction or the introduction of argon. The results indicate the involvement of hydrogen in the anode reaction （three-phase-boundary reaction including gas, electrolyte and electrode） and give the possibility for the utilization of reducing gas anodes for aluminum electrolysis.展开更多
A series of SnO2‐based catalysts modified by Mn, Zr, Ti and Pb oxides with a Sn/M （M=Mn, Zr, Ti and Pb） molar ratio of 9/1 were prepared by a co‐precipitation method and used for CH4 and CO oxidation. The Mn3＋, ...A series of SnO2‐based catalysts modified by Mn, Zr, Ti and Pb oxides with a Sn/M （M=Mn, Zr, Ti and Pb） molar ratio of 9/1 were prepared by a co‐precipitation method and used for CH4 and CO oxidation. The Mn3＋, Zr4＋, Ti4＋and Pb4＋cations are incorporated into the lattice of tetragonal rutile SnO2 to form a solid solution structure. As a consequence, the surface area and thermal stability of the catalysts are improved. Moreover, the oxygen species of the modified catalysts become easier to be reduced. Therefore, the oxidation activity over the catalysts was improved, except for the one modified by Pb oxide. Manganese oxide demonstrates the best promotional effects for SnO2. Using an X‐ray diffraction extrapolation method, the lattice capacity of SnO2 for Mn2O3 was 0.135 g Mn2O3/g SnO2, which indicates that to form stable solid solution, only 21%Sn4＋cations in the lattice can be maximally replaced by Mn3＋. If the amount of Mn3＋cations is over the capacity, Mn2O3 will be formed, which is not favorable for the activity of the catalysts. The Sn rich samples with only Sn‐Mn solid solution phase show higher activity than the ones with excess Mn2O3 species.展开更多
Catalytic activity and hydrothermal stability are both crucial for the application of the selective catalytic reduction of NO_(x)with NH_(3)(NH_(3)-SCR)catalyst in diesel vehicles.In this study,a tin(Sn)-modified Ce-N...Catalytic activity and hydrothermal stability are both crucial for the application of the selective catalytic reduction of NO_(x)with NH_(3)(NH_(3)-SCR)catalyst in diesel vehicles.In this study,a tin(Sn)-modified Ce-Nb mixed-oxide catalyst was synthesized as an NH_(3)-SCR catalyst for NO_(x)emission control.After the intro-duction of Sn,both the NH_(3)-SCR activity and the hydrothermal stability of the catalyst were remarkably promoted.Even after hydrothermal aging at 1000℃,the developed Ce_(1)Sn_(2)Nb_(1)O_(x)catalyst achieved more than 90%NO_(x)conversion at 325-500℃.Various methods,including N2-physisorption,X-ray diffraction,in-situ high-temperature X-ray diffraction,high-resolution transmission electron microscopy,X-ray pho-toelectron spectroscopy,X-ray absorption fine-structure spectroscopy,temperature-programmed reduc-tion of hydrogen,temperature-programmed desorption of ammonia,and density functional theory calculations were used to investigate the promotional effects induced by the Sn species.The characteri-zation results showed that the addition of Sn not only promoted the formation of the Ce-Nb active phase but also improved its thermal stability,contributing to the excellent NH_(3)-SCR performance and hydrothermal stability.This study provides an excellent sintering-resistance catalyst for the application of diesel engine NO_(x)emission control.展开更多
A unique discontinuous lamellar microstructure of titanium alloys consisting of lamellar colonies at prior β-Ti grain boundaries and internal interwoven α-laths is prepared by a TiH_(2)-based powder metallurgy metho...A unique discontinuous lamellar microstructure of titanium alloys consisting of lamellar colonies at prior β-Ti grain boundaries and internal interwoven α-laths is prepared by a TiH_(2)-based powder metallurgy method.The α-variants get various crystallographic orientations and become discontinuous during vacuum annealing at 700℃.Remarkably,nanoscale phase δ-TiH compound layers are generated between α-laths and β-strips,so that dislocations are piled up at the α/δ/βinterfaces during tensile deformation.This leads to dislocation slips being confined to individual α-laths,with differentslips and particularly pyramidal<c+a>slips being activated.The efficiency of wavy slip is promoted and the work hardening rate is enhanced.Finally,the combined effect of dispersed micro-shear bands and lath distortions is considered contributive for alleviating the stress concentration at grain boundaries,resulting in a high-promising synergy of enhanced ultimate tensile strength of 1080 MPa and good elongation to fracture of 13.6%.展开更多
Al_(2)O_(3)-based eutectic ceramics are considered as promising candidates for ultra-high-temperature structural materials due to their exceptional thermal stability and mechanical properties.Nonetheless,several chall...Al_(2)O_(3)-based eutectic ceramics are considered as promising candidates for ultra-high-temperature structural materials due to their exceptional thermal stability and mechanical properties.Nonetheless,several challenges must be overcome before they can be widely used.This paper reviews in detail the tailoring of microstructure from the aspect of process parameters,the updated knowledge gained in microstructure(crystallographic orientation,high-resolution interfacial structures)and the latest means of optimizing eutectic microstructure(seed-induced method,introducing low-energy grain boundaries and high-entropy phase).Additionally,the paper explores future techniques for the fabrication of bulk ceramic materials and effective toughening approaches.This review highlights the achievements made especially in the last 15 years,current limitations in Al_(2)O_(3)-based eutectic ceramics,and offers comprehensive insights and strategic guidance for further mechanical breakthroughs.展开更多
The reaction behavior between CaO–Al_(2)O_(3)–La_(2)O_(3)-based slags and La-bearing FeCrAl melt was quantitatively characterized,which was further compared with the reaction behavior of CaO–SiO_(2)-based slags.Bas...The reaction behavior between CaO–Al_(2)O_(3)–La_(2)O_(3)-based slags and La-bearing FeCrAl melt was quantitatively characterized,which was further compared with the reaction behavior of CaO–SiO_(2)-based slags.Based on this,the new type of mold flux for La-bearing FeCrAl alloy continuous casting was designed and its basic properties were evaluated.The results showed that the order of reaction degree of fluxing agents in CaO–Al_(2)O_(3)–La_(2)O_(3)-based slags is(Na_(2)O)>(B_(2)O_(3))>(Li_(2)O),and the percentages of mass change of fluxing agents were 85.8,54.29 and 42.35 wt.%,respectively.Moreover,the addition of(Li_(2)O)and(Na_(2)O)promoted the reaction between(CaO)and[Al],and the reaction degree of the former was weaker than that of the latter,which was due to the greater effect of(Na_(2)O)on the activity of(CaO)and(Al_(2)O_(3))than(Li_(2)O).Compared with the reactivity of CaO–SiO_(2)-based slags,the percentages of mass change of Al and La caused by slag–steel reaction decreased by 10.63–14.36 and 39.78–50.49 wt.%,respectively.The percentages of mass change of(Al_(2)O_(3)),(La_(2)O_(3))and(CaO)in slags highest increased by 17.71,17.98,and 7.81 wt.%,respectively.The reactivity of CaO–Al_(2)O_(3)–La_(2)O_(3)-based slags was significantly weakened.Ultimately,the new type of mold flux was designed and the composition range was determined.The fundamental properties of new mold flux basically meet the theoretical requirements for La-bearing FeCrAl alloy continuous casting.展开更多
To explore high value-added utilization pathways of fly ash,the mesoporous structure of silicon dioxide extracted from fly ash(FA-SiO_(2))was utilized to restrict the dicyandiamide(DCDA)thermal degradation process.Thi...To explore high value-added utilization pathways of fly ash,the mesoporous structure of silicon dioxide extracted from fly ash(FA-SiO_(2))was utilized to restrict the dicyandiamide(DCDA)thermal degradation process.This produced chemically bonded interacting composite photocatalysts of FA-SiO,and graphitic-phase carbon nitride(g-C_(3)N_(4)).Compared with the spherical silicon dioxide prepared using tetraethyl orthosilicate(TEOS-SiO_(2)),the mesoporous structure of FA-SiO_(2),allowed DCDA to react in a smaller space,which facilitated the transformation of DCDA to melamine by the thermal degradation kinetics of FA-C_(3)N_(4)/DCDA.This ultimately boosted the formation of an N-atom-removed triazine ring structure and a multistage structure combining lumps and rods in the composite photocatalysts of g-C_(3)N_(4),and FA-SiO_(2),which led to a higher visible-light utilization efficiency,a suitable valence-band position,and the photocatalytic activity for methylene blue reaching 3.56 times that of g-C_(3)N_(4).The findings indicate that mesoporous FA-SiO,has the potential to improve the structural and photocatalytic properties of g-C_(3)N_(4),-based materials.展开更多
A series of three‐dimensionally ordered macroporous(3DOM)SnO2‐based catalysts modified by the cations Ce4+,Mn3+,and Cu2+have been prepared by using a colloidal crystal templating method and tested for soot combustio...A series of three‐dimensionally ordered macroporous(3DOM)SnO2‐based catalysts modified by the cations Ce4+,Mn3+,and Cu2+have been prepared by using a colloidal crystal templating method and tested for soot combustion under loose contact condition.XRD and STEM mapping results confirm that all the secondary metal cations have entered the lattice matrix of tetragonal rutile SnO2 to form non‐continuous solid solutions,thus impeding crystallization and improving the surface areas and pore volumes of the modified catalysts.In comparison with regular SnO2 nanoparticles,the 3DOM SnO2 displays evidently improved activity,testifying that the formation of the 3DOM structure can anchor the soot particulates in the macro‐pores,which ensures that the contact of the soot particles with the active sites on the 3DOM skeleton is more easily formed,thus benefiting the target reaction.With the incorporation of the secondary metal cations,the activity of the catalyst can be further improved due to the formation of more abundant mobile oxygen species.In summary,these effects are believed to be the major factors responsible for the activity of the catalyst.展开更多
The sensitivity and the recovery behavior of SnO_2-based gas sensor prepared from a commercial SnO_2 powder were tested under the low concentration of DMMP(0.5μg/g) in the flow system at 350℃.In order to improve the...The sensitivity and the recovery behavior of SnO_2-based gas sensor prepared from a commercial SnO_2 powder were tested under the low concentration of DMMP(0.5μg/g) in the flow system at 350℃.In order to improve the sensitivity of the sensor,promoters such as NiO,Nb_2O_5,MoO_3,and Sb_2O_3 were added into SnO_2 powder.The sensitivities were increased up to 80% from 50% but they were not recovered.Only the SnO2-based gas sensor promoted with MoO_3 and Sb_2O_3 was recovered after detection of DMMP,although the recovery rate was slow.In particular,the SnO_2-based sensor promoted with 5wt% of MoO_3 and 1wt% of Sb_2O_3 simultaneously showed an complete recovery ability,though its sensitivity was 40% which was lower than that of SnO_2 gas sensor without promoters.This ability was discussed in terms of catalytic roles of promoters.展开更多
Effects of VC/Cr3C2 on the microstructure and mechanical properties of Ti（C,N）-based cermets were studied. The microstructure was investigated by means of optical microscopy, X-ray diffractometry as well as scanning...Effects of VC/Cr3C2 on the microstructure and mechanical properties of Ti（C,N）-based cermets were studied. The microstructure was investigated by means of optical microscopy, X-ray diffractometry as well as scanning electron microscopy in combination with energy dispersive spectrometry. Mechanical properties, such as transverse rupture strength, hardness and fracture toughness, were measured. The results show that there are black core-grey rim structure and white core-grey rim structure in the microstructure. The grains become fine due to the VC/Cr3C2, and the grains of cermet added with 0.75VC/0.25Cr3C2 are refined most remarkably. The black core becomes finer with the increase of VC addition and rim phase becomes thicker with the decrease of Cr3C2 addition. The porosity increases with the increase of VC addition in VC/Cr3C2. Compared with the cermet free of VC/Cr3C2, the transverse rupture strength and hardness of cermets with VC/Cr3C2 are both improved, and the maximum values are both found for the cermet with 0.25VC/0.75Cr3C2. The fracture toughness can be effectively promoted by adding VC/Cr3C2 with an appropriate ratio of VC to Cr3C2, and the maximum value is found for the cermet with 0.5VC/0.5Cr3C2.展开更多
Thermoelectric materials,enabling the directing conversion between heat and electricity,are one of the promising candidates for overcoming environmental pollution and the upcoming energy shortage caused by the over-co...Thermoelectric materials,enabling the directing conversion between heat and electricity,are one of the promising candidates for overcoming environmental pollution and the upcoming energy shortage caused by the over-consumption of fossil fuels.Bi2Te3-based alloys are the classical thermoelectric materials working near room temperature.Due to the intensive theoretical investigations and experimental demonstrations,significant progress has been achieved to enhance the thermoelectric performance of Bi2Te3-based thermoelectric materials.In this review,we first explored the fundamentals of thermoelectric effect and derived the equations for thermoelectric properties.On this basis,we studied the effect of material parameters on thermoelectric properties.Then,we analyzed the features of Bi2Te3-based thermoelectric materials,including the lattice defects,anisotropic behavior and the strong bipolar conduction at relatively high temperature.Then we accordingly summarized the strategies for enhancing the thermoelectric performance,including point defect engineering,texture alignment,and band gap enlargement.Moreover,we highlighted the progress in decreasing thermal conductivity using nanostructures fabricated by solution grown method,ball milling,and melt spinning.Lastly,we employed modeling analysis to uncover the principles of anisotropy behavior and the achieved enhancement in Bi2Te3,which will enlighten the enhancement of thermoelectric performance in broader materials展开更多
The(Cu−10Sn)−Ni−MoS2 composites,prepared by powder metallurgy,were studied for the effects of Ni-coated MoS2 on the microstructure,mechanical properties and lubricating properties.The mechanism of effects of Ni and Mo...The(Cu−10Sn)−Ni−MoS2 composites,prepared by powder metallurgy,were studied for the effects of Ni-coated MoS2 on the microstructure,mechanical properties and lubricating properties.The mechanism of effects of Ni and MoS2 on the properties of composites was analyzed through a comparative experiment by adding Ni and MoS2 separately.The results show that the nickel wrapping around the MoS2 particles decreases the reaction rate of MoS2 with the copper matrix,and greatly improves the bonding of the matrix.The composites with 12 wt.%Ni-coated MoS2(C12)show the optimum performance including the mechanical properties and tribological behaviors.Under oil lubrication conditions,the friction coefficient is 0.0075 with a pressure of 8 MPa and a linear velocity of 0.25 m/s.The average dry friction coefficient,sliding against 40Cr steel disc,is measured to be 0.1769 when the linear velocity and pressure are 0.25 m/s and 4 MPa,respectively.展开更多
Advanced high-strength steels (AHSSs) have been gradually applied to modern auto industry, as they have the advantages of improving the steel strength and lightening the car weight, which not only ensures the safety b...Advanced high-strength steels (AHSSs) have been gradually applied to modern auto industry, as they have the advantages of improving the steel strength and lightening the car weight, which not only ensures the safety but also saves the energy. However, the high-aluminum (Al) content in AHSSs may react with SiO2 in conventional CaO-SiO2-based mold flux during the process of continuous casting, which leads to the deterioration of the mold flux properties and a poor slab quality. Then, the non-reactive CaO-Al2O3-based mold flux was proposed and has been developing for the casting process of high-Al steels, but there are some problems of low consumption and insufficient lubrication that need to be solved. Thus, previous researches on the effect of each component on the properties of CaO-Al2O3-based mold flux were systematically summarized, and the situation of plant trials on CaO-Al2O3-based mold flux was evaluated. The results indicated that the proposed CaO-Al2O3-based mold fluxes could avoid the slag-metal reaction problems;however, the problems of lubri-cation, crystallization and heat transfer issues still exist. Therefore, tremendous works still need to be conducted for the development of new generation of CaO-Al2O3-based mold flux system. The review was performed aiming to provide a technical guidance for designing and optimizing CaO-Al2O3-based mold flux system that meets the demand of the continuous casting process of high-Al steels.展开更多
We investigated the influence of soaking time on the semi-conductivity and nonlinear electrical properties of TiO2- based varistor ceramic samples. We used a single sintering process and fabricated six disk samples of...We investigated the influence of soaking time on the semi-conductivity and nonlinear electrical properties of TiO2- based varistor ceramic samples. We used a single sintering process and fabricated six disk samples of （Sr, Bi, Si, Ta）-doped TiO2- based varistor ceramics sintered at 1 250℃ for 0.5 h, 1.0 h, 2.0 h, 3.0 h, 4.0 h, and 5.0 h, respectively. The samples were characterized by X-ray diffraction, breakdown voltage, and complex impedance. The results show that as the soaking time increases from 0.5 h to 5.0 h, the breakdown voltage drops before rising while the nonlinear coefficient increases and then decreases. We suggest that, considering both grain semi-conductivity and nonlinear electrical properties of the TiO2-based varistor ceramics, the optimal soaking time is between 2.0 h and 3.0 h.展开更多
The electrochemical corrosion behavior of Ti（C,N）-based cermets with different Mo2C additions was investigated in freely aerated 10% H2SO4 and potentiodynamic polarization of all the materials was conducted from -0....The electrochemical corrosion behavior of Ti（C,N）-based cermets with different Mo2C additions was investigated in freely aerated 10% H2SO4 and potentiodynamic polarization of all the materials was conducted from -0.5 to 1.5 V. There are two passive regions for all polarization curves. The first should be attributed to passive film formation due to Ti（C,N）, while the second may be due to the presence of Ni. Corrosion current density increases with M02C content increasing, from 2.06×10^-3 to 6.70×10^-3 mA/cm2. It is indicated that the corrosion resistance of Ti（C,N）-based cermets decreases with the increase of Mo2C addition. A skeleton of Ti（C,N） gains is observed after dissolution of Ni. The inner rim of cermets, rich in Mo2C, is corroded along with Ni binder and is more serious with the increase of Mo2C content. The secondary carbide Mo2C can be oxidized and dissolved in sulphuric acid.展开更多
In recent decades,many additives with difierent characteristics have been applied to strengthen and toughen Al_2O_(3)一based ceramic cutting tool materials.Among them,SiC whiskers and SiC nanoparticles showed excellen...In recent decades,many additives with difierent characteristics have been applied to strengthen and toughen Al_2O_(3)一based ceramic cutting tool materials.Among them,SiC whiskers and SiC nanoparticles showed excellent performance in improving the material properties.W hile no attempts have been made to add SiC whiskers and SiC nanoparticles together into the ceramic matrix and the synergistically toughening efects of them have not been studied.An Al_2O_(3)一SiCw-SiCno advanced ceramic cutting tool material is fabricated by adding both one--dimensional SiC whiskers and zero--dimensional SiC nanoparticles into the Al_2O_(3)matrix with an efective dispersing and mixing process.The composites with 25 vo1%SiC whiskers and 25 vo1%SiC nanoparticles alone are also investegated for comparison purposes.Results show that the Al_2O_(3)一SiCw-SiCno composite with both 20 vo1%SiC whiskers and 5 vo1%SiC nanoparticles additives have much improved mechanical properties.The flexural strength of Al_2O_(3)-SiCw-SiCⅡD is 730~95 MPa and fracture toughness is 5.6±0.6 MPa’m.The toughening and strengthening mechanisms of SiC whiskers and nanoparticles are studied when they are added either individually or in combination.It is indicated that when SiC whiskers and nanoparticles are added together,the grains are further refined and homogenized,so that the microstructure and fracture mode ratio is modified.The SiC nanoparticles are found helpful to enhance the toughening efects of the SiC whiskers.The proposed research helps to enrich the types of ceramic cutting too1 and is benefit to expand the application range of ceramic cutting too1.展开更多
The effects of CaO/Al2O3 ratio on viscosity and structure of the CaO-Al2O3-based fluoride-free mould fluxes were investigated with the CaO/Al2O3 ratio varied from 1 to 4 and the content of SiO2 fixed at 7 wt.%. The in...The effects of CaO/Al2O3 ratio on viscosity and structure of the CaO-Al2O3-based fluoride-free mould fluxes were investigated with the CaO/Al2O3 ratio varied from 1 to 4 and the content of SiO2 fixed at 7 wt.%. The increase in the CaO/Al2O3 ratio from 1 to 2 lowered the viscosity of the flux melts. The viscosity increased slightly with the CaO/Al2O3 ratio from 2 to 3, and this increase became significant with further increasing CaO/Al2O3 ratio to 4. Both break temperature and apparent activation energy were found to be increased with the increase in CaO/Al2O3 ratio from 2 to 4. There was no break temperature available in the flux with CaO/Al2O3 ratio of 1. Changing the CaO/Al2O3 ratio from 1 to 2 decreased the apparent activation energy. Equilibrium phases of the fluxes were calculated using FactSage 7.1 and the major phases were found to be varied with the CaO/Al2O3 ratio. Structures of tested mould fluxes were analysed using Fourier transform infrared spectroscopy. The results showed that the increase in the CaO/Al2O3 ratio from 1 to 2 decreased the complexity of the structure, leading to a reduced viscosity. With the increase in the CaO/Al2O3 ratio from 2 to 4, both solid phase precipitation and melt structure contributed to the variation of viscosity.展开更多
Herein,we review the significant of ordered macroporous(OM)TiO_(2)-based catalysts for boosting pho-tocatalytic CO_(2)reduction.Based on the need to improve the three key factors of photogenerated charge separation ef...Herein,we review the significant of ordered macroporous(OM)TiO_(2)-based catalysts for boosting pho-tocatalytic CO_(2)reduction.Based on the need to improve the three key factors of photogenerated charge separation eficiency,solar energy utilization and CO_(2)adsorption rate during the conversion of CO_(2)to H_(2)O,we summarized five modification measures:including doping ions into OM TiO_(2),introducing sec-ond semiconductor coupling and noble metal nanoparticles for fabricating multiple Z-scheme heterojunc-tions,constructing hierarchical pore and carbon-loaded OM TiO_(2)materials,which effectively enhance the absorption rate of visible light,the separation rate of electrons-hole pairs and the selection of multiple active sites.The OM structured TiO_(2)-based photocatalysts solve the single or multiple key factors for en-hancing photocatalytic performances during CO_(2)conversion.The catalytic mechanism and pathways of OM structured TiO_(2)-based photocatalysts for CO_(2)reduction are discussed and summarized.It provides new insights on the development of high-efficient catalyst for photocatalytic CO_(2)conversion to solar fu-els.展开更多
A new technology was developed to recover multiple valuable elements from the spent Al2O3-based catalyst by X-ray phase analysis and exploratory experiments. The experimental results show that in the condition of roas...A new technology was developed to recover multiple valuable elements from the spent Al2O3-based catalyst by X-ray phase analysis and exploratory experiments. The experimental results show that in the condition of roasting temperature of 750℃ and roasting time of 30 min, molar ratio of Na2O to Al2O3 of 1.2, the leaching rates of alumina, vanadium and molybdenum in the spent catalyst are 97.2%, 95.8% and 98.9%, respectively. Vanadium and molybdenum in sodium aluminate solution can be recovered by precipitators A and B, and the precipitation rates of vanadium and molybdenum are 94.8% and 92.6%. Al（OH）3 was prepared from sodium aluminate solution in the carbonation decomposition process, and the purity of Al2O3 is 99.9% after calcination, the recovery of alumina reaches 90.6% in the whole process; the Ni-Co concentrate was leached by sulfuric acid, a nickel recovery of 98.2% and cobalt recovery over 98.5% can be obtained under the experimental condition of 30% H2SO4, 80℃, reaction time 4 h, mass ratio of liquid to solid 8, stirring rate 800r/min.展开更多
基金the National Natural Science Foundation of China(No.51778296)。
文摘In an electrocatalyst with a heterointerface structure,the different interfaces can efficiently adjust the catalyst’s conductivity and electron arrangement,thereby enhancing the activity of the electrocatalyst.Ultrathin and smaller Ni Fe LDH was successfully constructed on the surface of SnOnanosheet supported NF by layer by layer assembly,and exhibits lower overpotential of 234 mV at a current density of 10 m A cm,which only increases by 6.4%even at a high current density of 100 mA cm.The excellent OER activity of catalyst is attributed to the contribution of the semiconductor SnOelectron transport layer.Through experiments and characterization,3d structure SnOnanosheets control the growth of ultra-thin nickel-iron,the hierarchical interface between SnOand Ni Fe LDH can change the electron arrangement around the iron and nickel active centers at the interface,resulting the valence states of iron slightly increased and Nicontent increased.The result will promote the oxidation of water.Meanwhile,the SnOsemiconductor as electron transport layer is conducive to trapping electrons generated in oxidation reaction,promoting electrons transferring from the Ni Fe LDH active center to the Ni substrate more quickly,and enhance the activity of Ni Fe LDH.It also shows excellent activity in an electrolyte solution containing 0.5 M methanol and 1 M KOH,and only 1.396 V(vs.RHE)is required to drive a current density of 10 mA cm.
基金Project(51404001)supported by the National Natural Science Foundation of ChinaProject([2014]1685)supported by the Scientific Research Foundation for the Returned Overseas Chinese Scholars,Ministry of Education,China
文摘A novel SnO2-based gas anode was developed for aluminum electrolysis in molten cryolite at 850 ＆#176;C to reduce energy consumption and decrease CO2 emissions. Hydrogen was introduced into the anode, participating in the anode reaction. Carbon and aluminum were used as the cathode and reference electrodes, respectively. Cyclic voltammetry was applied in the cell to investigate the electrochemical behavior of oxygen ion on platinum and SnO2-based materials. The potential for oxygen evolution on these electrode materials was determined. Then, galvanostatic electrolysis was performed on the gas anode, showing a significant depolarization effect （a decrease of ~0.8 V of the anode potential） after the introduction of hydrogen, compared with no gas introduction or the introduction of argon. The results indicate the involvement of hydrogen in the anode reaction （three-phase-boundary reaction including gas, electrolyte and electrode） and give the possibility for the utilization of reducing gas anodes for aluminum electrolysis.
基金supported by the National Natural Science Foundation of China (21263015,21567016 and 21503106)the Education Department Foundation of Jiangxi Province (KJLD14005 and GJJ150016)the Natural Science Foundation of Jiangxi Province (20142BAB213013 and 20151BBE50006),which are greatly acknowledged by the authors~~
文摘A series of SnO2‐based catalysts modified by Mn, Zr, Ti and Pb oxides with a Sn/M （M=Mn, Zr, Ti and Pb） molar ratio of 9/1 were prepared by a co‐precipitation method and used for CH4 and CO oxidation. The Mn3＋, Zr4＋, Ti4＋and Pb4＋cations are incorporated into the lattice of tetragonal rutile SnO2 to form a solid solution structure. As a consequence, the surface area and thermal stability of the catalysts are improved. Moreover, the oxygen species of the modified catalysts become easier to be reduced. Therefore, the oxidation activity over the catalysts was improved, except for the one modified by Pb oxide. Manganese oxide demonstrates the best promotional effects for SnO2. Using an X‐ray diffraction extrapolation method, the lattice capacity of SnO2 for Mn2O3 was 0.135 g Mn2O3/g SnO2, which indicates that to form stable solid solution, only 21%Sn4＋cations in the lattice can be maximally replaced by Mn3＋. If the amount of Mn3＋cations is over the capacity, Mn2O3 will be formed, which is not favorable for the activity of the catalysts. The Sn rich samples with only Sn‐Mn solid solution phase show higher activity than the ones with excess Mn2O3 species.
基金supported by the National Natural Science Foundation of China(52225004 and 22276202)the National Key Research and Development Program of China(2022YFC3701804)the Youth Innovation Promotion Association of Chinese Academy of Sciences(2019045).
文摘Catalytic activity and hydrothermal stability are both crucial for the application of the selective catalytic reduction of NO_(x)with NH_(3)(NH_(3)-SCR)catalyst in diesel vehicles.In this study,a tin(Sn)-modified Ce-Nb mixed-oxide catalyst was synthesized as an NH_(3)-SCR catalyst for NO_(x)emission control.After the intro-duction of Sn,both the NH_(3)-SCR activity and the hydrothermal stability of the catalyst were remarkably promoted.Even after hydrothermal aging at 1000℃,the developed Ce_(1)Sn_(2)Nb_(1)O_(x)catalyst achieved more than 90%NO_(x)conversion at 325-500℃.Various methods,including N2-physisorption,X-ray diffraction,in-situ high-temperature X-ray diffraction,high-resolution transmission electron microscopy,X-ray pho-toelectron spectroscopy,X-ray absorption fine-structure spectroscopy,temperature-programmed reduc-tion of hydrogen,temperature-programmed desorption of ammonia,and density functional theory calculations were used to investigate the promotional effects induced by the Sn species.The characteri-zation results showed that the addition of Sn not only promoted the formation of the Ce-Nb active phase but also improved its thermal stability,contributing to the excellent NH_(3)-SCR performance and hydrothermal stability.This study provides an excellent sintering-resistance catalyst for the application of diesel engine NO_(x)emission control.
基金financially supported by the National Natural Science Foundation of China(Nos.52301145,52275329)the Applied Basic Research Program of Liaoning Province,China(No.2023JH2/101300158)+1 种基金the Fundamental Research Fund for the Central Universities,China(No.N2202010)the Key Research Programs of High Education Institutions in Henan Province,China(No.24A430017).
文摘A unique discontinuous lamellar microstructure of titanium alloys consisting of lamellar colonies at prior β-Ti grain boundaries and internal interwoven α-laths is prepared by a TiH_(2)-based powder metallurgy method.The α-variants get various crystallographic orientations and become discontinuous during vacuum annealing at 700℃.Remarkably,nanoscale phase δ-TiH compound layers are generated between α-laths and β-strips,so that dislocations are piled up at the α/δ/βinterfaces during tensile deformation.This leads to dislocation slips being confined to individual α-laths,with differentslips and particularly pyramidal<c+a>slips being activated.The efficiency of wavy slip is promoted and the work hardening rate is enhanced.Finally,the combined effect of dispersed micro-shear bands and lath distortions is considered contributive for alleviating the stress concentration at grain boundaries,resulting in a high-promising synergy of enhanced ultimate tensile strength of 1080 MPa and good elongation to fracture of 13.6%.
基金financially supported by the National Natural Science Foundation of China(No.52171046)National Natural Science Foundation of China-key programme(No.52234010)the Fundamental Research Funds for the Central Universities and Shaanxi Provincial Key Science and Technology Innovation Team(No.2023-CX-TD-14).
文摘Al_(2)O_(3)-based eutectic ceramics are considered as promising candidates for ultra-high-temperature structural materials due to their exceptional thermal stability and mechanical properties.Nonetheless,several challenges must be overcome before they can be widely used.This paper reviews in detail the tailoring of microstructure from the aspect of process parameters,the updated knowledge gained in microstructure(crystallographic orientation,high-resolution interfacial structures)and the latest means of optimizing eutectic microstructure(seed-induced method,introducing low-energy grain boundaries and high-entropy phase).Additionally,the paper explores future techniques for the fabrication of bulk ceramic materials and effective toughening approaches.This review highlights the achievements made especially in the last 15 years,current limitations in Al_(2)O_(3)-based eutectic ceramics,and offers comprehensive insights and strategic guidance for further mechanical breakthroughs.
基金supported by the National Natural Science Foundation of China(Grant Nos.52174321,52274339 and 52074186).
文摘The reaction behavior between CaO–Al_(2)O_(3)–La_(2)O_(3)-based slags and La-bearing FeCrAl melt was quantitatively characterized,which was further compared with the reaction behavior of CaO–SiO_(2)-based slags.Based on this,the new type of mold flux for La-bearing FeCrAl alloy continuous casting was designed and its basic properties were evaluated.The results showed that the order of reaction degree of fluxing agents in CaO–Al_(2)O_(3)–La_(2)O_(3)-based slags is(Na_(2)O)>(B_(2)O_(3))>(Li_(2)O),and the percentages of mass change of fluxing agents were 85.8,54.29 and 42.35 wt.%,respectively.Moreover,the addition of(Li_(2)O)and(Na_(2)O)promoted the reaction between(CaO)and[Al],and the reaction degree of the former was weaker than that of the latter,which was due to the greater effect of(Na_(2)O)on the activity of(CaO)and(Al_(2)O_(3))than(Li_(2)O).Compared with the reactivity of CaO–SiO_(2)-based slags,the percentages of mass change of Al and La caused by slag–steel reaction decreased by 10.63–14.36 and 39.78–50.49 wt.%,respectively.The percentages of mass change of(Al_(2)O_(3)),(La_(2)O_(3))and(CaO)in slags highest increased by 17.71,17.98,and 7.81 wt.%,respectively.The reactivity of CaO–Al_(2)O_(3)–La_(2)O_(3)-based slags was significantly weakened.Ultimately,the new type of mold flux was designed and the composition range was determined.The fundamental properties of new mold flux basically meet the theoretical requirements for La-bearing FeCrAl alloy continuous casting.
基金supported by the Medical Special Cultivation Project of Anhui University of Science and Technology(Nos.YZ2023H2B013 and YZ2023H2B012),China.
文摘To explore high value-added utilization pathways of fly ash,the mesoporous structure of silicon dioxide extracted from fly ash(FA-SiO_(2))was utilized to restrict the dicyandiamide(DCDA)thermal degradation process.This produced chemically bonded interacting composite photocatalysts of FA-SiO,and graphitic-phase carbon nitride(g-C_(3)N_(4)).Compared with the spherical silicon dioxide prepared using tetraethyl orthosilicate(TEOS-SiO_(2)),the mesoporous structure of FA-SiO_(2),allowed DCDA to react in a smaller space,which facilitated the transformation of DCDA to melamine by the thermal degradation kinetics of FA-C_(3)N_(4)/DCDA.This ultimately boosted the formation of an N-atom-removed triazine ring structure and a multistage structure combining lumps and rods in the composite photocatalysts of g-C_(3)N_(4),and FA-SiO_(2),which led to a higher visible-light utilization efficiency,a suitable valence-band position,and the photocatalytic activity for methylene blue reaching 3.56 times that of g-C_(3)N_(4).The findings indicate that mesoporous FA-SiO,has the potential to improve the structural and photocatalytic properties of g-C_(3)N_(4),-based materials.
基金the Natural Science Foundation of China(21567016,21503106)the Natural Science Foundation of Jiangxi Province(20171BAB213013)+3 种基金the Education Department Foundation of Jiangxi Province(KJLD14005)National Key Research and Development Program of China(2016YFC0209302)the Innovation Fund Designated for Graduate Students of Jiangxi Province(YC2015-B017)the Innovation Fund Designated for Undergraduate Students of China(201701035)~~
文摘A series of three‐dimensionally ordered macroporous(3DOM)SnO2‐based catalysts modified by the cations Ce4+,Mn3+,and Cu2+have been prepared by using a colloidal crystal templating method and tested for soot combustion under loose contact condition.XRD and STEM mapping results confirm that all the secondary metal cations have entered the lattice matrix of tetragonal rutile SnO2 to form non‐continuous solid solutions,thus impeding crystallization and improving the surface areas and pore volumes of the modified catalysts.In comparison with regular SnO2 nanoparticles,the 3DOM SnO2 displays evidently improved activity,testifying that the formation of the 3DOM structure can anchor the soot particulates in the macro‐pores,which ensures that the contact of the soot particles with the active sites on the 3DOM skeleton is more easily formed,thus benefiting the target reaction.With the incorporation of the secondary metal cations,the activity of the catalyst can be further improved due to the formation of more abundant mobile oxygen species.In summary,these effects are believed to be the major factors responsible for the activity of the catalyst.
文摘The sensitivity and the recovery behavior of SnO_2-based gas sensor prepared from a commercial SnO_2 powder were tested under the low concentration of DMMP(0.5μg/g) in the flow system at 350℃.In order to improve the sensitivity of the sensor,promoters such as NiO,Nb_2O_5,MoO_3,and Sb_2O_3 were added into SnO_2 powder.The sensitivities were increased up to 80% from 50% but they were not recovered.Only the SnO2-based gas sensor promoted with MoO_3 and Sb_2O_3 was recovered after detection of DMMP,although the recovery rate was slow.In particular,the SnO_2-based sensor promoted with 5wt% of MoO_3 and 1wt% of Sb_2O_3 simultaneously showed an complete recovery ability,though its sensitivity was 40% which was lower than that of SnO_2 gas sensor without promoters.This ability was discussed in terms of catalytic roles of promoters.
基金Project (090414185) supported by the Natural Science Foundation of Anhui Province, China
文摘Effects of VC/Cr3C2 on the microstructure and mechanical properties of Ti（C,N）-based cermets were studied. The microstructure was investigated by means of optical microscopy, X-ray diffractometry as well as scanning electron microscopy in combination with energy dispersive spectrometry. Mechanical properties, such as transverse rupture strength, hardness and fracture toughness, were measured. The results show that there are black core-grey rim structure and white core-grey rim structure in the microstructure. The grains become fine due to the VC/Cr3C2, and the grains of cermet added with 0.75VC/0.25Cr3C2 are refined most remarkably. The black core becomes finer with the increase of VC addition and rim phase becomes thicker with the decrease of Cr3C2 addition. The porosity increases with the increase of VC addition in VC/Cr3C2. Compared with the cermet free of VC/Cr3C2, the transverse rupture strength and hardness of cermets with VC/Cr3C2 are both improved, and the maximum values are both found for the cermet with 0.25VC/0.75Cr3C2. The fracture toughness can be effectively promoted by adding VC/Cr3C2 with an appropriate ratio of VC to Cr3C2, and the maximum value is found for the cermet with 0.5VC/0.5Cr3C2.
基金Project supported by the Australian Research CouncilZhi-Gang Chen thanks the USQ start-up grantstrategic research grant
文摘Thermoelectric materials,enabling the directing conversion between heat and electricity,are one of the promising candidates for overcoming environmental pollution and the upcoming energy shortage caused by the over-consumption of fossil fuels.Bi2Te3-based alloys are the classical thermoelectric materials working near room temperature.Due to the intensive theoretical investigations and experimental demonstrations,significant progress has been achieved to enhance the thermoelectric performance of Bi2Te3-based thermoelectric materials.In this review,we first explored the fundamentals of thermoelectric effect and derived the equations for thermoelectric properties.On this basis,we studied the effect of material parameters on thermoelectric properties.Then,we analyzed the features of Bi2Te3-based thermoelectric materials,including the lattice defects,anisotropic behavior and the strong bipolar conduction at relatively high temperature.Then we accordingly summarized the strategies for enhancing the thermoelectric performance,including point defect engineering,texture alignment,and band gap enlargement.Moreover,we highlighted the progress in decreasing thermal conductivity using nanostructures fabricated by solution grown method,ball milling,and melt spinning.Lastly,we employed modeling analysis to uncover the principles of anisotropy behavior and the achieved enhancement in Bi2Te3,which will enlighten the enhancement of thermoelectric performance in broader materials
基金Projects(51371099,51501091)supported by the National Natural Science Foundation of China。
文摘The(Cu−10Sn)−Ni−MoS2 composites,prepared by powder metallurgy,were studied for the effects of Ni-coated MoS2 on the microstructure,mechanical properties and lubricating properties.The mechanism of effects of Ni and MoS2 on the properties of composites was analyzed through a comparative experiment by adding Ni and MoS2 separately.The results show that the nickel wrapping around the MoS2 particles decreases the reaction rate of MoS2 with the copper matrix,and greatly improves the bonding of the matrix.The composites with 12 wt.%Ni-coated MoS2(C12)show the optimum performance including the mechanical properties and tribological behaviors.Under oil lubrication conditions,the friction coefficient is 0.0075 with a pressure of 8 MPa and a linear velocity of 0.25 m/s.The average dry friction coefficient,sliding against 40Cr steel disc,is measured to be 0.1769 when the linear velocity and pressure are 0.25 m/s and 4 MPa,respectively.
基金National Natural Science Foundation of China(U1760202,51661130154)the Newton Advanced fellowship(NA 150320)is greatly acknowledged.
文摘Advanced high-strength steels (AHSSs) have been gradually applied to modern auto industry, as they have the advantages of improving the steel strength and lightening the car weight, which not only ensures the safety but also saves the energy. However, the high-aluminum (Al) content in AHSSs may react with SiO2 in conventional CaO-SiO2-based mold flux during the process of continuous casting, which leads to the deterioration of the mold flux properties and a poor slab quality. Then, the non-reactive CaO-Al2O3-based mold flux was proposed and has been developing for the casting process of high-Al steels, but there are some problems of low consumption and insufficient lubrication that need to be solved. Thus, previous researches on the effect of each component on the properties of CaO-Al2O3-based mold flux were systematically summarized, and the situation of plant trials on CaO-Al2O3-based mold flux was evaluated. The results indicated that the proposed CaO-Al2O3-based mold fluxes could avoid the slag-metal reaction problems;however, the problems of lubri-cation, crystallization and heat transfer issues still exist. Therefore, tremendous works still need to be conducted for the development of new generation of CaO-Al2O3-based mold flux system. The review was performed aiming to provide a technical guidance for designing and optimizing CaO-Al2O3-based mold flux system that meets the demand of the continuous casting process of high-Al steels.
基金Funded by the Natural Science Foundation of China (No. 50872001 and No. 50642038)the Scientific Research Foundation of Education Ministry of Anhui Province (No. 2005KJ224 and No. KJ2007B132)the Graduate Student Innovation Programs of Anhui University (No. 20072006)
文摘We investigated the influence of soaking time on the semi-conductivity and nonlinear electrical properties of TiO2- based varistor ceramic samples. We used a single sintering process and fabricated six disk samples of （Sr, Bi, Si, Ta）-doped TiO2- based varistor ceramics sintered at 1 250℃ for 0.5 h, 1.0 h, 2.0 h, 3.0 h, 4.0 h, and 5.0 h, respectively. The samples were characterized by X-ray diffraction, breakdown voltage, and complex impedance. The results show that as the soaking time increases from 0.5 h to 5.0 h, the breakdown voltage drops before rising while the nonlinear coefficient increases and then decreases. We suggest that, considering both grain semi-conductivity and nonlinear electrical properties of the TiO2-based varistor ceramics, the optimal soaking time is between 2.0 h and 3.0 h.
基金Project(51074110) supported by the National Natural Science Foundation of ChinaProject(10GGZD080GX-268) supported by Chengdu Science and Technology Program, China
文摘The electrochemical corrosion behavior of Ti（C,N）-based cermets with different Mo2C additions was investigated in freely aerated 10% H2SO4 and potentiodynamic polarization of all the materials was conducted from -0.5 to 1.5 V. There are two passive regions for all polarization curves. The first should be attributed to passive film formation due to Ti（C,N）, while the second may be due to the presence of Ni. Corrosion current density increases with M02C content increasing, from 2.06×10^-3 to 6.70×10^-3 mA/cm2. It is indicated that the corrosion resistance of Ti（C,N）-based cermets decreases with the increase of Mo2C addition. A skeleton of Ti（C,N） gains is observed after dissolution of Ni. The inner rim of cermets, rich in Mo2C, is corroded along with Ni binder and is more serious with the increase of Mo2C content. The secondary carbide Mo2C can be oxidized and dissolved in sulphuric acid.
基金Supported by National Natural Science Foundation of China(Grant No.51175305)
文摘In recent decades,many additives with difierent characteristics have been applied to strengthen and toughen Al_2O_(3)一based ceramic cutting tool materials.Among them,SiC whiskers and SiC nanoparticles showed excellent performance in improving the material properties.W hile no attempts have been made to add SiC whiskers and SiC nanoparticles together into the ceramic matrix and the synergistically toughening efects of them have not been studied.An Al_2O_(3)一SiCw-SiCno advanced ceramic cutting tool material is fabricated by adding both one--dimensional SiC whiskers and zero--dimensional SiC nanoparticles into the Al_2O_(3)matrix with an efective dispersing and mixing process.The composites with 25 vo1%SiC whiskers and 25 vo1%SiC nanoparticles alone are also investegated for comparison purposes.Results show that the Al_2O_(3)一SiCw-SiCno composite with both 20 vo1%SiC whiskers and 5 vo1%SiC nanoparticles additives have much improved mechanical properties.The flexural strength of Al_2O_(3)-SiCw-SiCⅡD is 730~95 MPa and fracture toughness is 5.6±0.6 MPa’m.The toughening and strengthening mechanisms of SiC whiskers and nanoparticles are studied when they are added either individually or in combination.It is indicated that when SiC whiskers and nanoparticles are added together,the grains are further refined and homogenized,so that the microstructure and fracture mode ratio is modified.The SiC nanoparticles are found helpful to enhance the toughening efects of the SiC whiskers.The proposed research helps to enrich the types of ceramic cutting too1 and is benefit to expand the application range of ceramic cutting too1.
文摘The effects of CaO/Al2O3 ratio on viscosity and structure of the CaO-Al2O3-based fluoride-free mould fluxes were investigated with the CaO/Al2O3 ratio varied from 1 to 4 and the content of SiO2 fixed at 7 wt.%. The increase in the CaO/Al2O3 ratio from 1 to 2 lowered the viscosity of the flux melts. The viscosity increased slightly with the CaO/Al2O3 ratio from 2 to 3, and this increase became significant with further increasing CaO/Al2O3 ratio to 4. Both break temperature and apparent activation energy were found to be increased with the increase in CaO/Al2O3 ratio from 2 to 4. There was no break temperature available in the flux with CaO/Al2O3 ratio of 1. Changing the CaO/Al2O3 ratio from 1 to 2 decreased the apparent activation energy. Equilibrium phases of the fluxes were calculated using FactSage 7.1 and the major phases were found to be varied with the CaO/Al2O3 ratio. Structures of tested mould fluxes were analysed using Fourier transform infrared spectroscopy. The results showed that the increase in the CaO/Al2O3 ratio from 1 to 2 decreased the complexity of the structure, leading to a reduced viscosity. With the increase in the CaO/Al2O3 ratio from 2 to 4, both solid phase precipitation and melt structure contributed to the variation of viscosity.
基金supported by the National Key Research and Development Program of China(No.2022YFB3504100)the National Natural Science Foundation of China(No.21972166).
文摘Herein,we review the significant of ordered macroporous(OM)TiO_(2)-based catalysts for boosting pho-tocatalytic CO_(2)reduction.Based on the need to improve the three key factors of photogenerated charge separation eficiency,solar energy utilization and CO_(2)adsorption rate during the conversion of CO_(2)to H_(2)O,we summarized five modification measures:including doping ions into OM TiO_(2),introducing sec-ond semiconductor coupling and noble metal nanoparticles for fabricating multiple Z-scheme heterojunc-tions,constructing hierarchical pore and carbon-loaded OM TiO_(2)materials,which effectively enhance the absorption rate of visible light,the separation rate of electrons-hole pairs and the selection of multiple active sites.The OM structured TiO_(2)-based photocatalysts solve the single or multiple key factors for en-hancing photocatalytic performances during CO_(2)conversion.The catalytic mechanism and pathways of OM structured TiO_(2)-based photocatalysts for CO_(2)reduction are discussed and summarized.It provides new insights on the development of high-efficient catalyst for photocatalytic CO_(2)conversion to solar fu-els.
基金Project(2003 UDBEA00C020) supported by the Collaborative Project of School and Province of Yunnan Province
文摘A new technology was developed to recover multiple valuable elements from the spent Al2O3-based catalyst by X-ray phase analysis and exploratory experiments. The experimental results show that in the condition of roasting temperature of 750℃ and roasting time of 30 min, molar ratio of Na2O to Al2O3 of 1.2, the leaching rates of alumina, vanadium and molybdenum in the spent catalyst are 97.2%, 95.8% and 98.9%, respectively. Vanadium and molybdenum in sodium aluminate solution can be recovered by precipitators A and B, and the precipitation rates of vanadium and molybdenum are 94.8% and 92.6%. Al（OH）3 was prepared from sodium aluminate solution in the carbonation decomposition process, and the purity of Al2O3 is 99.9% after calcination, the recovery of alumina reaches 90.6% in the whole process; the Ni-Co concentrate was leached by sulfuric acid, a nickel recovery of 98.2% and cobalt recovery over 98.5% can be obtained under the experimental condition of 30% H2SO4, 80℃, reaction time 4 h, mass ratio of liquid to solid 8, stirring rate 800r/min.
