265 results about "Cerium(IV) oxide" patented technology

The invention provides a low-smoke halogen-free flame-retardant cable material and a preparation method thereof, and belongs to the field of cable materials. The low-smoke halogen-free flame-retardant cable material is prepared from the following chemical components: 32 to 40 parts of nitrile rubber, 22 to 27 parts of natural rubber, 8 to 12 parts of benzoxazole-siloxane copolymer containing phosphate dynamic bonds, 13 to 15 parts of core-shell-sheath three-stage structure flame retardant, 4 to 6 parts of hexaphenoxy cyclotriphosphazene modified carbon nanotubes, 2 to 3 parts of europium-doped mesoporous cerium dioxide and 3 to 4 parts of nano zinc oxide. The composite material is prepared from the following components in parts by weight: 3 to 4 parts of carbon nanotube grafted montmorillonite hybrid, 2 to 3 parts of lubricant, 0.8 to 1.2 parts of cross-linking agent, 0.3 to 0.4 part of accelerant, 0.4 to 0.6 part of dicumyl peroxide and 0.1 to 0.2 part of antioxidant. Unification of high flame retardance, low smoke, excellent mechanical property and processability of the cable material is realized.

The invention relates to the technical field of biodiesel hydrogenation catalysts, and particularly discloses a hydrogenation catalyst of organic bentonite loaded cerium-zirconium solid solution and nickel-molybdenum phosphide as well as a preparation method and application of the hydrogenation catalyst. The hydrogenation catalyst with the organic bentonite loaded with the cerium-zirconium solid solution and the nickel-molybdenum phosphide comprises an organic bentonite carrier, the cerium-zirconium solid solution and the nickel-molybdenum phosphide, the loading capacity of the cerium-zirconium solid solution on the organic bentonite carrier is 2-2.5 wt%; the cerium-zirconium solid solution comprises cerium dioxide and zirconium dioxide; the loading capacity of the nickel molybdenum phosphide on the organic bentonite carrier is 10-15 wt%; and the nickel molybdenum phosphide is Ni2Mo3P. The organobentonite carrier provides an acid site and promotes deoxidation path optimization, the layered structure of the organobentonite carrier can limit the cerium-zirconium solid solution and the nickel-molybdenum phosphide, and organic groups are also embedded into the layered structure, so that the organic compatibility of the organobentonite carrier to biodiesel is improved, and the catalytic efficiency is improved. The cerium-zirconium solid solution provides oxygen vacancies, promotes hydrogenation / deoxidation, and improves the thermal stability and sintering resistance of the catalyst.

The invention discloses high-toughness ultrathin flexible glass and a preparation method thereof, and relates to the technical field of glass manufacturing. The ultrathin flexible glass is prepared from the following raw materials: silicon dioxide, aluminum oxide, lithium oxide, sodium oxide, magnesium oxide, a modified nano reinforced phase, a high-temperature melting regulator and cerium dioxide. The modified nano reinforced phase is prepared by the following steps: pre-treating silicon carbide and silicon nitride with hydrochloric acid, and mixing with nano zirconium oxide to obtain a mixture; and modifying the mixture with a silane coupling agent to obtain the modified nano reinforced phase. The high-temperature melting regulator is a mixture of lithium borate, sodium sulfate and lithium fluoride. The preparation method of the ultra-thin flexible glass comprises the following steps: preparing the modified nano reinforced phase, melting and homogenizing the glass, forming the glass substrate, and preparing the ultra-thin flexible glass. The ultra-thin flexible glass prepared by the invention has relatively high fracture toughness and structural rigidity, excellent flexibility and bending fatigue durability, and excellent thermal shock resistance.

The invention discloses a corrosion-resistant aluminum alloy profile and a preparation method thereof, and belongs to the technical field of aluminum alloy profiles. By optimizing the components of the corrosion-resistant aluminum alloy, the strength of the aluminum alloy profile can be guaranteed, and the corrosion resistance of the aluminum alloy profile is positively influenced. Besides, the corrosion-resistant coating is formed on the surface of the corrosion-resistant aluminum alloy base material in a laser cladding mode, the corrosion resistance of the aluminum alloy profile can be remarkably improved while the application performance of the aluminum alloy profile is guaranteed, and in the corrosion-resistant coating, nickel powder can enhance pitting corrosion resistance and intergranular corrosion resistance, so that the corrosion resistance of the aluminum alloy profile is improved. The adhesive force with an aluminum alloy base material is improved; the boron nitride can improve the acid resistance and wear resistance of the surface of the aluminum alloy profile and block a corrosion channel; the lanthanum oxide and the cerium dioxide have a synergistic effect, so that surface grains can be refined, air holes generated in the cladding process are reduced, the compactness of the coating is improved, the compatibility with an aluminum alloy base material is promoted, and the apparent quality of the aluminum alloy profile is guaranteed.

The invention discloses a polyetherketoneketone high-temperature-resistant wear-resistant non-stick coating and a preparation method thereof. The coating is prepared from the following components in parts by mass: 13 to 30 parts of a resin matrix group (containing 12 to 25 parts of titanium modified polyether ketone ketone resin, 1 to 5 parts of fluorine-free viscous resin and 0.65 to 6 parts of aluminum oxide), 0.5 to 3 parts of a nano reinforced group (containing 0.5 to 3 parts of KH-550 modified nano titanium dioxide, 0.025 to 0.6 part of cerium dioxide and 0.5 to 3 parts of boron nitride) and 62 to 71 parts of an auxiliary agent group. The preparation method comprises the following steps: 1) taking diphenyl ether, paraphthaloyl chloride and isophthaloyl chloride as monomers, and synthesizing titanium modified polyether ketone ketone resins with different viscosities through segmented polymerization (1.5-2.0 hours or 3.0-4.0 hours); 2) respectively preparing a smooth bottom layer water dispersion slurry and a wrinkled surface layer water dispersion slurry; and (3) forming a compact bottom layer and a micro-wrinkle surface layer on the base material by adopting a layered spraying and stepped sintering process (280-320 DEG C, 10-20 minutes). The whole system of the coating is fluorine-free and has temperature resistance gt; the coating has the characteristics of high temperature resistance (350DEG C), wear resistance (Taber wear rate of 3-5mg / 1000r), non-sticking (contact angle gt, 100 DEG C) and heavy corrosion resistance, and is suitable for cooking utensils and chemical equipment.

The invention discloses a preparation method of a nickel-based catalyst and the nickel-based catalyst. The preparation method of the nickel-based catalyst comprises the following steps: S1, completely dissolving an acid source, cerium salt and a solvent; s2, carrying out hydrothermal reaction on the solution obtained in the step S1; s3, carrying out solid-liquid separation on the product obtained in the step S2, and washing, drying and calcining the obtained solid product to form a carrier which is cerium dioxide derived from a metal organic framework; s4, an active component is loaded on the carrier, and the active component is metallic nickel or nickel oxide. According to the preparation method of the nickel-based catalyst, the nickel-based catalyst with relatively high specific surface area and developed mesoporous channels can be prepared, thermal agglomeration of active sites of metal nickel can be avoided, and the stability and catalytic performance of the nickel-based catalyst are improved.

The invention discloses high-strength high-temperature-resistant fireproof industrial glass and a preparation method thereof, and relates to the technical field of glass manufacturing. The industrial glass is prepared from the following raw materials: silicon dioxide, boric oxide, aluminum oxide, sodium oxide, potassium oxide, niobium phosphate, a composite reinforcing component and a clarifying agent, the composite reinforcing component is prepared from hafnium oxide, gadolinium oxide and zinc oxide; the clarifying agent is obtained by mixing cerium dioxide and tin oxide. The preparation method of the industrial glass comprises the following steps: preparing functional components, melting glass, forming a glass substrate, and preparing the industrial glass. The prepared industrial glass is high in strength, good in high-temperature stability and excellent in fireproof performance.

The invention relates to a high-gloss black decorative glass prepared from sludge incineration ash by an all-electric melting method. The high-gloss black decorative glass comprises the following raw material components in percentage by mass: 75-79% of fly ash, 5-7% of calcium carbonate, 9-10% of sodium carbonate, 5-6% of potassium alkali, 1-1.4% of boric acid, 0.03-0.04% of porous carbon, 0.06-0.08% of semi-coke powder, 0.16-0.22% of cobaltosic oxide, 0.1-0.2% of cerium dioxide, 0.04-0.06% of neodymium oxide, 0.5-0.7% of waste zircon brick powder and 0.03-0.05% of yttrium oxide. The dedusting ash is electrostatic dedusting ash collected by incineration of filtered sludge in a municipal sewage treatment plant, and belongs to hazardous waste; the porous carbon is rich in a hierarchical pore structure of sub-nano pores (0.5-1.0 nm). According to the method, a closed-loop production mode that waste is used for treating waste is constructed, high-added-value decorative materials are produced while energy consumption is reduced, and environmental protection investment is converted into economic benefits.

The invention relates to the technical field of glass, in particular to an alkali-free aluminoborosilicate glass composite clarifying agent and a clarifying method thereof. The alkali-free aluminoborosilicate glass composite clarifying agent is prepared from the following raw materials in percentage by mass on the basis of the total mass of alkali-free aluminoborosilicate glass: 0.4 to 5.5 percent of halogen alkaline earth metal salt, 0.03 to 0.4 percent of lanthanum oxide, 0.01 to 0.4 percent of tin dioxide and 0.01 to 0.3 percent of cerium dioxide. The alkali-free aluminoborosilicate glass composite clarifying agent is applied to alkali-free aluminoborosilicate glass, and the problems that the alkali-free aluminoborosilicate glass is poor in clarifying effect and has many bubble defects are solved; the corrosion of high-temperature molten glass to refractory materials at parts such as a tank furnace and the like is reduced, so that the number of stone defects of the refractory materials in the glass is reduced, and the service life of the refractory materials of the furnace is prolonged.

The invention discloses a self-repairing sealant for a perovskite component and a preparation method of the self-repairing sealant, and belongs to the technical field of sealants, a D-A bond is introduced into a prepolymer A, nano-zinc oxide is loaded on the surface of mesoporous cerium dioxide powder, heptadecafluorodecyl trimethoxysilane and KH-550 are grafted to the surface of composite cerium dioxide for modification, and the self-repairing sealant for the perovskite component is obtained. The preparation method comprises the following steps: compounding cerium dioxide powder, crosslinking with a prepolymer A and a prepolymer B, and combining with other raw materials to obtain the self-repairing sealant for the perovskite component, under the condition of high temperature of 65-90 DEG C, the forward reaction of D-A bonds is facilitated, the effect of self-repairing cracks is achieved, meanwhile, the hydrophobicity is increased by fluorine groups on the compounded cerium dioxide powder, and the self-repairing performance of the sealant is improved. The nano-zinc oxide and the cerium dioxide are added, so that the sealant can keep a good sealing effect in a high-temperature and high-humidity environment, meanwhile, the nano-zinc oxide and the cerium dioxide synergistically play a role in resisting ultraviolet aging, the service life of the self-repairing sealant is further prolonged, and in addition, the flexibility is also improved to a certain extent.

The invention relates to a surface modification method of a Co-CeO2 abrasive material based on coordination of a silane coupling agent and a surfactant. According to the method, in the modification of the chemically mechanical polished cerium dioxide abrasive, different types of surfactants are added by utilizing a method of combining a silane coupling agent and the surfactants, and more active sites are introduced on the surface of cerium dioxide through the silane coupling agent, so that the surface of the cerium dioxide is modified. And meanwhile, the surfactant is ionized to generate anions, so that the electrostatic repulsion among the nanoparticles is enhanced, the dispersity of the cerium dioxide abrasive is enhanced, and the polishing rate and the polishing quality are further improved. When the obtained material is used as an abrasive material, the removal rate is increased to # imgabs0 #, and compared with a traditional abrasive material, the removal rate is increased by about 40%.

The invention relates to the technical field of biomass-based semiconductor bifunctional materials and environmental restoration, in particular to a Baijiu vinasse biochar / cerium oxide / cadmium zinc sulfur solid solution heterojunction bifunctional material as well as a preparation method and application of the Baijiu vinasse biochar / cerium oxide / cadmium zinc sulfur solid solution heterojunction bifunctional material. The method comprises the following steps: in an inert atmosphere, carrying out pyrolysis on waste Baijiu vinasse to obtain biochar; the method comprises the following steps: mixing biochar and an activator, and carrying out activation pyrolysis in an inert atmosphere to obtain alkali-activated biochar; the preparation method comprises the following steps: dispersing a cadmium source, a zinc source, thiourea, a surfactant, alkali-activated charcoal and cerium dioxide in a solvent to form a dispersion liquid, and carrying out a heating reaction to obtain the Baijiu vinasse charcoal / cerium oxide / cadmium-zinc-sulfur solid solution heterojunction bifunctional material. The adsorption performance of the material is improved due to the remarkable specific surface area of the alkali-activated biochar component; the construction of the cerium oxide / cadmium zinc sulfur solid solution heterojunction significantly accelerates the migration of photon-generated carriers, endows the material with excellent adsorption-photocatalytic performance, has good reusability, and can remove pesticide pollutants in water.

The invention discloses cerium dioxide particles and a preparation method thereof, the preparation method comprises the following steps: 1) cerium salt and fluxing salt are mixed and ground to obtain initial mixed salt; (2) mixing and grinding the initial mixed salt and a surface additive to obtain mixed salt containing the surface additive; 3) roasting the mixed salt containing the surface additive to obtain a roasted product; 4) cleaning the roasted product, and drying the solid obtained after cleaning to obtain cerium dioxide particles; wherein the molar ratio of the cerium salt to the fluxing salt is less than or equal to 1: 3; no additional solvent is added in the step 1), the step 2) and the step 3). According to the preparation method disclosed by the invention, the fluxing salt is adopted as an auxiliary agent for reaction, no extra solvent is added, alkali is not needed to be added for preparing a precursor, and the generation amount of waste liquid can be reduced while the cerium dioxide with good dispersity, narrow particle size distribution and average particle size less than or equal to 130nm can be obtained.

The application discloses a kind of corrosion-resistant aluminum alloy profiles and preparation method thereof, belong to aluminum alloy profile technical field.The application can ensure the strength of aluminum alloy profile by optimizing the composition of corrosion-resistant aluminum alloy, and has a positive effect on the corrosion resistance of aluminum alloy profile.In addition, the application forms a corrosion-resistant coating on the surface of the corrosion-resistant aluminum alloy substrate by laser cladding, which can significantly improve the corrosion resistance of the aluminum alloy profile while ensuring the application performance of the aluminum alloy profile.In the corrosion-resistant coating, nickel powder can enhance the resistance to pitting and intergranular corrosion, and improve the adhesion to the aluminum alloy substrate.Boron nitride can improve the surface acid resistance and wear resistance of the aluminum alloy profile, and block the corrosion channel.Lanthanum oxide and cerium dioxide have a synergistic effect, which can refine the surface grains, reduce the pores generated during the cladding process, improve the compactness of the coating, promote the compatibility with the aluminum alloy substrate, and ensure the appearance quality of the aluminum alloy profile.

The invention belongs to the field of water pollution treatment, and particularly relates to a method for degrading chlorophenol organic pollutants in water by activating persulfate with a cobalt-cerium dioxide monatomic catalyst in the presence of bicarbonate radicals. According to the invention, cerium nitrate hexahydrate is calcined in a muffle furnace to obtain cerium dioxide. A catalyst precursor is prepared by a traditional isovolumetric impregnation method. The prepared catalyst precursor is annealed at different temperatures to obtain a series of catalysts, the catalytic performance of Co1-CeO2-700 is optimal, and the Co1-CeO2-700 has more excellent catalytic performance in the presence of bicarbonate radicals. The preparation method provided by the invention has the advantages of simple steps, convenience in operation, quick effect of treating chlorophenol, high product yield and low cost, and has good economic value and social benefit. The prepared monatomic catalyst has the advantages of being high in atom utilization rate, good in stability, excellent in catalytic effect and the like, and is expected to become a key technology for solving actual water environment organic pollution.

The invention relates to a method for preparing a mesoporous nano cerium dioxide powder material by taking a block copolymer as a template, which comprises the following steps: adding cerium nitrate hexahydrate into a mixture of ethanol and the block copolymer for reaction, and carrying out carbon thermal reduction to obtain mesoporous nano cerium dioxide. The obtained cerium dioxide material has the advantages of high activity, high dispersity, high content of trivalent cerium, uniform size, large specific surface area and the like. The preparation method is simple in step, low in equipment requirement, low in raw material price, good in repeatability and easy to amplify and industrially produce, so that the CMP process cost is reduced.

The present application provides a method for synthesizing cyclic carbonate by urea alcoholysis. The method comprises: synthesizing urea and diol into cyclic carbonate under the action of an ionic liquid modified cerium dioxide catalyst, wherein the molar ratio of the urea to the diol is 1:(1-5), the dosage of the ionic liquid modified cerium dioxide catalyst is 1%-10% of the mass of the urea, and the synthesized cyclic carbonate has a reaction temperature of 130-170°C, and a reaction pressure of 5-30 kPa. The method of the present application is simple and convenient to operate, no solvent needs to be added, the product and the catalyst are easy to separate, and continuous production is easy to realize. Moreover, the used ionic liquid modified cerium dioxide catalyst has a simple preparation process, low costs, high catalytic performance and good selectivity, and is easy to recycle.

The invention relates to the technical field of coatings, in particular to a nano anticorrosive coating. The invention provides a nano anticorrosive coating which comprises a component A and a component B. The component A comprises 40-100 parts by weight of bisphenol A epoxy resin, 0.3-5 parts by weight of cerium dioxide modified hexagonal boron nitride nanosheets and 60-85 parts by weight of lamellar structure zinc-aluminum alloy powder. And the component B comprises 20-40 parts of a polyamide curing agent. The zinc-aluminum alloy particles can enhance the toughness of the coating, and the cerium dioxide and hexagonal boron nitride are added to improve the hardness and wear resistance of the coating. And cerium dioxide and hexagonal boron nitride are added, so that the impedance modulus value of the coating is remarkably improved, the corrosion current density is reduced, and the corrosion resistance of the coating is enhanced. In a salt spray test, the modified coating shows better salt spray resistance, and a coating stripping area is not expanded.

The invention discloses an industrial flue gas denitration filter bag and a preparation method thereof, and relates to the technical field of flue gas denitration. The industrial flue gas denitration filter bag comprises PTFE (Polytetrafluoroethylene) fibers, PPS (Polyphenylene Sulfide) fibers, PI (Polyimide) fibers and PTFE loaded fibers. Wherein the PTFE loaded fiber is a PTFE fiber layer loaded with a modified molecular sieve catalyst; the modified molecular sieve catalyst takes a molecular sieve coated with modified nanorods as a carrier, a vanadium-titanium composite oxide as an active catalytic component and a cerium-titanium composite oxide as a co-catalytic component; the modified nanorod is a molybdenum-tungsten composite oxide modified cerium dioxide nanorod. By introducing the modified molecular sieve catalyst prepared from cerium dioxide nanorods, lanthanum nitrate, molybdenum trioxide and other raw materials, the denitration capacity, the ammonia escape prevention capacity, the sulfur poisoning resistance, the hydrothermal stability and the working life are further improved, and an active temperature window is widened. Therefore, the method has a wider application prospect.

The invention discloses a high-temperature-resistant inorganic antibacterial ceramic glaze and a preparation process, and relates to the technical field of ceramic glaze preparation, the glaze is composed of a basic glaze and a zinc oxide-doped cerium dioxide inorganic antibacterial agent, and the basic glaze comprises feldspar, quartz, kaolin, calcite and talc. The preparation process comprises the following steps: mixing the raw materials, carrying out wet ball milling, adding the antibacterial agent and the dispergator, stirring at a high speed, sieving to remove iron, aging, glazing and sintering at a high temperature. In the process, an iron removal integrated unit integrating a two-stage vibration screening function and an automatic iron scraping function is adopted, and efficient and continuous iron removal operation is achieved. The obtained glaze can resist high-temperature sintering of 1150-1200 DEG C, the glaze surface is smooth and uniform, the glaze surface has lasting and efficient broad-spectrum antibacterial performance, glaze surface defects caused by iron impurities are effectively avoided, and the product yield and quality stability are improved.

The invention discloses a composite oxidized particle filter material and a preparation method thereof, and particularly relates to the technical field of oxidized particle filter materials, the filter material takes a ternary composite oxide of cerium dioxide-cobaltosic oxide-nickel oxide as a core material, has a hierarchical pore structure, and is coated with a pH responsive coating on the surface; the preparation method comprises the following steps: S1, biological template pretreatment; S2, sol-gel synthesis; S3, graded pore channel construction; and S4, surface modification. According to the invention, the cerium dioxide-cobaltosic oxide-nickel oxide ternary composite oxide is taken as a core, pollutants are efficiently degraded under visible light and infrared light by virtue of graded pore channels, surface copper nanoparticles and internal up-conversion nanoparticles, and the quaternary ammonium salt compound grafted on the surface has good antibacterial property, can inhibit microorganism breeding and prolong the service life of the filter material; the whole preparation process is suitable for industrial production.

The invention belongs to the field of nano biological materials, and particularly relates to dextran-modified cerium dioxide nanoparticles as well as a preparation method and application thereof. The preparation method comprises the following steps: dissolving glucan in water, adding cerium nitrate hexahydrate, and standing until the glucan and the cerium nitrate hexahydrate are completely dissolved to obtain a solution 1; the concentration of the glucan in the solution 1 is 48-52 mg / mL, and the concentration of the cerium nitrate hexahydrate in the solution 1 is 35-40 mg / mL; dropwise adding an alkali solution into the solution 1 under a stirring state until the color of the solution 1 is changed from colorless to yellow, and keeping the stirring condition until the solution 1 is changed into clear dark brown to obtain a solution 2; and centrifuging the solution 2 to remove large particles, and dialyzing and purifying to remove unreacted raw materials to obtain the dextran-modified cerium dioxide nanoparticles. The dextran-modified cerium dioxide nanoparticles have broad-spectrum antibacterial activity, high efficiency and low toxicity, and have a good immune activation effect and a wide application prospect.

The invention relates to a building exterior wall coating and a preparation method thereof, and belongs to the technical field of building coatings. The coating is composed of a composite inorganic-organic hybrid film forming base material, a nano composite flame-retardant filler, a bio-based thickener, a photoresponsive hydrophobic aid, a low-foam wetting dispersant and deionized water. Wherein the composite base material forms an interpenetrating network structure through compounding of sodium potassium silicate and phosphate modified polyacrylate emulsion, and has inorganic phase hardness and organic phase flexibility; the nano flame-retardant filler adopts an Mg-Al layered dihydroxy oxide and cerium dioxide core-shell structure, and zinc borate is loaded to realize multi-stage flame retardance. The preparation method comprises ultrasonic-assisted emulsion polymerization, electrostatic self-assembly filler compounding and gradient curing processes, and during construction, a layered spraying and ultraviolet activation combined technology is adopted. The super-hydrophobic self-cleaning flame-retardant coating has excellent flame retardance, super-hydrophobic self-cleaning performance and long-acting weather resistance.

The invention relates to cerium dioxide and a preparation method and application thereof, and the preparation method of the hexagonal cerium dioxide comprises the following steps: (1) carrying out first mixing on cerium salt, doped metal salt, a solvent, inorganic acid and organic acid to obtain a first mixture; the doped metal salt comprises praseodymium salt and / or neodymium salt; (2) under a hydrothermal condition, carrying out second mixing on the first mixture, ammonia water and ammonium salt to obtain a second mixture with the pH value of 3.5-6, and carrying out sol-gel reaction to obtain hexagonal cerium dioxide sol; and (3) carrying out post-treatment on the hexagonal cerium dioxide sol to obtain the hexagonal cerium dioxide. According to the preparation method of the hexagonal cerium dioxide, provided by the invention, a mixing process and a reaction process of cerium salt and specific raw materials are designed, so that the hexagonal cerium dioxide with regular particle shape, good size uniformity and high purity and crystallinity is obtained.

The invention relates to a microcrystalline plate produced on the basis of hazardous waste incineration ash, which comprises fly ash, bottom slag, silica sand, anhydrous sodium carbonate, sodium nitrate, anhydrous potassium carbonate, sodium fluosilicate, stannic oxide, nickel oxide, cobalt oxide, anhydrous borax, cerium dioxide, manganese dioxide and lanthanum oxide, an all-electric melting glass kiln is adopted for vitrification, a crystallization process adopts a one-step method for crystallization, and the crystallization process adopts a one-step method for crystallization. The fly ash and the bottom slag are obtained by incinerating medical wastes belonging to hazardous wastes in a rotary kiln, and are belonging to hazardous wastes; the method not only helps to solve the problem of disposal of the medical waste incineration ash, but also can promote development of the green building material industry, and conforms to the strategic target of sustainable development.

The invention discloses a preparation method of a cerium-based compound catalyst for electrosynthesis of hydrogen peroxide through an oxygen reduction reaction. The method comprises the following steps: 1) dissolving cerium nitrate and urea in deionized water, and carrying out hydrothermal reaction and heat treatment to obtain cerium dioxide; 2) carrying out heat treatment on a certain amount of melamine to obtain graphite-phase carbon nitride; (3) adding the prepared cerium dioxide and graphite-phase carbon nitride into methanol and stirring; and finally, performing heat treatment on a sample in a muffle furnace to obtain the cerium dioxide composite graphite phase carbon nitride catalyst. The cerium-based compound catalyst prepared by the preparation method has excellent performance on a two-electron oxygen reduction reaction.

The invention discloses surface modified cerium dioxide powder as well as a preparation method and application thereof, and the preparation method comprises the following steps: 1) modifying cerium dioxide with the particle size of 0.55-2.5 mu m with KH550 to obtain KH550 modified cerium dioxide powder; 2) mixing the KH550 modified cerium oxide powder obtained in the step 1) with C1-C3 alkyl alcohol and C1-C3 alkyl acid, and then reacting at 45-75 DEG C for 0.5-2.5 hours to obtain an initial reaction mixture; 3) adding polyethylene glycol carboxylic acid with the molecular weight of 350-2000 into the initial reaction mixture at the temperature of 45-75 DEG C, and continuously reacting for 3-8 hours to obtain a final reactant; 4) cooling the final reactant, carrying out solid-liquid separation, washing the separated solid, and drying the washed solid to obtain surface modified cerium dioxide powder; wherein the mass ratio of the KH550 modified cerium oxide powder to the polyethylene glycol carboxylic acid is 6: (0.6-3.7). According to the preparation method, the surface modified cerium dioxide powder with smaller particle size, better dispersity and larger Zeta potential absolute value can be obtained.

The invention discloses a catalyst for preparing tetrahydrofuran through furan hydrogenation as well as preparation and application of the catalyst. According to the invention, the catalyst comprises a first metal component, a second metal component, an auxiliary agent and a carrier, the first metal component is nickel, the second metal component is copper, the auxiliary agent is cerium dioxide, and the carrier is silicon dioxide or aluminum oxide. Based on the mass percent of the catalyst, the catalyst comprises the following components in percentage by mass: 10-60% of Ni element, 1-20% of Cu element, 0.5-5% of cerium dioxide and the balance of a carrier. The catalyst is prepared by adopting a traditional impregnation method, the preparation method is simple, the required catalytic reaction condition is mild, the catalyst has the advantages of high catalytic activity and high tetrahydrofuran selectivity, and by adopting the catalyst, the yield of tetrahydrofuran prepared by furan hydrogenation can be improved, and the catalyst has a good industrial application prospect.

The application relates to the technical field of isotope separation, in particular to a SiO2@CeO2 core-shell material with silica supported cerium dioxide, a preparation method thereof and application of the SiO2@CeO2 core-shell material in Ge / Ga separation. 68 Efficient adsorption of Ge and 68 Effective elution of Ga; the SiO2@CeO2 core-shell material is used as a stationary phase, hydrochloric acid is used as a mobile phase, Ge / Ga is efficiently separated based on solid-phase extraction, and therefore the SiO2@CeO2 core-shell material can be used as 68 Ge- 68 Ga generator column packing.

The invention discloses nano cerium dioxide as well as a preparation method and application thereof. The preparation method of the nano cerium dioxide comprises the following steps: (1) mixing a cerium salt mother solution and a sodium hypochlorite solution for reaction to obtain a first mixed solution; adding an alkali solution into the first mixed solution for reaction, adjusting the pH value of the reaction system to 6-6.5, continuing stirring for reaction at 80-90 DEG C for 1.5-3 hours, adding a sodium hypochlorite solution for reaction, adjusting the pH value of the reaction system to 6-6.5, and continuing stirring for reaction at 80-90 DEG C for 7-17 hours to obtain a second mixed solution; and (2) acidifying the second mixed solution, centrifuging to obtain a cerium dioxide precipitate, and drying the cerium dioxide precipitate to obtain the nano cerium dioxide. According to the method, the superfine nano spherical cerium dioxide particles with good dispersity, uniform particle size and high purity can be prepared at low temperature without adding any organic reagent. The method is short in production period and suitable for large-scale production.