748 results about "Ammonium molybdate" patented technology

The invention relates to the technical field of waste catalyst recovery, and particularly discloses a method for recovering valuable metals from a waste catalyst containing vanadium and molybdenum. Comprising the following steps: S1, heating and roasting the waste catalyst containing vanadium and molybdenum, continuously heating and roasting, and cooling to obtain a roasted material; s2, mixing the roasted material with a sulfuric acid solution A containing oxalic acid, and heating and leaching to obtain a leaching solution A and a residue A; mixing the residue A with a sulfuric acid solution B containing thiourea and ethylenediaminetetraacetic acid, heating, carrying out secondary leaching to obtain a leaching solution B and a residue B, and washing the residue B with an acid solution to obtain a washing solution; combining the leaching solution and the washing solution to obtain a combined solution; s3, adjusting the pH value of the mixed solution to 2.5-3, then adjusting the pH value to 4.5-5, adding a dimethylglyoxime alcohol solution, and heating to obtain a purified solution; uniformly mixing the purified liquid with the extraction liquid to obtain an organic phase containing vanadium and molybdenum; and S4, reverse extraction and product preparation. The ammonium molybdate and the vanadium pentoxide obtained in the invention have high purity, and the recovery rate of vanadium and molybdenum is high.

The invention belongs to the technical field of stainless steel surface treatment, and particularly relates to a stainless steel passivation solution and a preparation method thereof. The water-based cutting fluid is prepared from the following raw materials: cerium salt, copper sulfate, citric acid, sodium dihydrogen phosphate, ammonium molybdate, sodium tungstate, aminated-silane modified SiO2 nanoparticles, polyethylene glycol, L-ascorbic acid, polyaspartic acid, an anti-settling agent, a surfactant and the balance of deionized water. According to the invention, a three-dimensional network skeleton is constructed by using aminated-epoxy group silane modified SiO2 nanoparticles, so that the problem of weak interface bonding force of a traditional passivation layer is solved; according to the formula, the proportion of biodegradable components such as citric acid and polyaspartic acid is extremely high, cerate adopts a low-toxicity rare earth compound, molybdenum / tungsten elements are fixed in a stable oxide form, the dosage of EDTA is remarkably reduced through a compounding technology, residual ions are adsorbed in combination with a three-dimensional network, and the balance of environment friendliness and long-acting corrosion resistance is achieved.

The invention discloses a compound yeast agent for anaerobic degradation of biodegradable plastics. The compound yeast agent comprises the following components in percentage by mass: 0.5-3% of fenpropathrin, 1-6% of nitrite, 1-4% of ammonium molybdate, 5-10% of PLA, 5-10% of nano starch, 3-6% of nano calcium carbonate, 1-5% of carbamide and the balance of a biodegradable resin carrier. The production method comprises the following steps: 1, dispersion treatment; 2, centralization processing; 3, carrying out structured treatment; 4, carrying out carrier implantation treatment; and 5, plasticizing and granulating. The compound yeast agent is added into the plastic, and the addition amount is 1-5%, so that the anaerobic degradation plastic is formed. According to the invention, anaerobic degradation can be regulated and controlled, and more importantly, anaerobic degradation also realizes that the degradable plastic disclosed by the invention is in a normal use condition, the plastic cannot be degraded quickly in light and oxygen environments, the aging property of the plastic is equivalent to that of a resin matrix of the plastic, and the physical and mechanical properties are ensured.

The invention belongs to the technical field of radioactive wastewater treatment, and particularly relates to composite aerogel for adsorbing Cs < + > and Sr < 2 + > in radioactive wastewater under an acidic condition and a preparation method of the composite aerogel. The preparation method of the composite aerogel comprises the following steps: (1) synthesizing ammonium phosphomolybdate / sodium alginate aerogel; (2) growing ZIF-8 on the surface of the ammonium phosphomolybdate / sodium alginate aerogel; and (3) modifying the surface of the material obtained in the step (2) by using potassium permanganate to generate MnO2, thereby obtaining the composite aerogel. The composite aerogel can efficiently adsorb Cs < + > and Sr < 2 + > in wastewater to realize efficient co-adsorption of double ions, and has the advantages of low energy consumption, high selective separation efficiency, capability of carrying out one-step curing separation, no secondary pollution and capability of effectively avoiding the defects of redundant separation operation and large waste liquid amount in a traditional method, and a high-capacity and easily-recycled adsorbent scheme is provided for radioactive wastewater treatment.

The invention provides a preparation method of a shape-controllable iron-molybdenum formaldehyde catalyst, and belongs to the technical field of catalyst preparation. The preparation method of the catalyst comprises the following steps: firstly, respectively mixing ammonium heptamolybdate tetrahydrate, ferric nitrate nonahydrate and a complexing agent, and dissolving in water to prepare a molybdenum-containing solution and an iron-containing solution; then mixing the molybdenum-containing solution and the iron-containing solution, adjusting the pH value, carrying out vacuum rotary evaporation to form sol, finally drying the sol to form xerogel, and roasting the xerogel to obtain a catalyst finished product. The coordination environment of Mo and Fe in the precursor solution is regulated and controlled through the complexing agent, uneven distribution of components is prevented, the uniform precursor solution is formed, the morphology and particle size of the catalyst are influenced by adjusting the pH of the solution and changing the precipitation rate of the precursor and the growth process of particles, and the catalyst with different morphologies and excellent comprehensive performance is prepared.

The invention discloses a special organic-inorganic compound fertilizer for improving the yield and quality of rice in a rice field, and belongs to the technical field of agricultural fertilizers. The compound fertilizer comprises a three-layer structure consisting of a porous core layer, a quick release coating layer and a biodegradable film, wherein the porous core layer is prepared from ammonium polyphosphate, potassium humate, nano charcoal modified chicken manure, mineral source potassium fulvate and sodium carboxymethyl cellulose-bentonite composite colloid; the quick-release coating layer is prepared from sulfur-resin double-layer coated urea, amino acid chelated zinc, alginic acid complex boron, silica sol, ammonium molybdate, 5-aminolevulinic acid and nano cerium oxide; the biodegradable film is prepared from a film forming solution and a bioactive microbial agent. Through the design of a three-layer structure and the combination of an organic-inorganic-microorganism synergistic technology, accurate matching of nutrient release and a rice fertilizer requirement rule is achieved, meanwhile, soil health and environmental protection are considered, and an innovative solution is provided for green high-yield rice planting.

The invention discloses a monatomic-cluster double-active-site efficient ammonia cracking hydrogen production catalyst and a preparation method thereof, and belongs to the field of new energy catalytic materials. The catalyst comprises a 2-methylimidazole zinc derived nitrogen-doped carbon-loaded cobalt monatomic carrier, a molybdenum disulfide nanosheet-loaded iron cluster carrier, monatomic active metal, cluster active metal and an auxiliary agent. Wherein the 2-methylimidazole zinc derived nitrogen-doped carbon-loaded cobalt monatomic carrier is prepared by the following steps: stirring 2-methylimidazole, zinc acetate and cobalt nitrate hexahydrate in methanol to generate a ZIF-8 precursor, washing, drying, and calcining in an H2 / Ar mixed atmosphere, thereby obtaining the 2-methylimidazole zinc derived nitrogen-doped carbon-loaded cobalt monatomic carrier; the molybdenum disulfide nanosheet loaded iron cluster carrier is prepared by carrying out hydrothermal reaction on ammonium molybdate and thiourea to generate MoS2 nanosheets and then loading iron clusters. The catalyst prepared by the invention has high activity, long service life and industrial applicability.

The embodiment of the invention relates to the photovoltaic field, and provides a cyanide-free electroplating silver-coated copper conductive material, a preparation method thereof and a crystalline silicon solar cell. The silver-coated copper electrode provided by the embodiment of the invention comprises a copper core and a copper-tin alloy electroplated layer coated on the surface of the copper core, the surface of the pre-plating material is coated with the silver electroplating layer; the surface of the silver-coated copper material is coated with the self-repairing layer; wherein the self-repairing layer comprises a resin film and a pH response type microcapsule, the microcapsule is embedded in the resin film, and the microcapsule is filled with an ammonium molybdate corrosion inhibitor. The copper-silver interface bonding force can be improved through the copper-tin alloy electroplated layer, and the silver layer material does not contain cyanogen and is environmentally friendly; the corrosion inhibitor in the pH response type microcapsule in the self-repairing film layer on the surface of the silver layer is released under a specific pH condition to form a protection film on the silver layer again, so that the self-repairing purpose is achieved, and the dynamic protection effect is achieved.

The invention discloses a method for recovering Mo and Fe from direct coal liquefaction oil residues, and belongs to the technical field of hydrometallurgy. The method comprises the steps of solvent extraction, roasting enrichment, wet leaching, extracting agent extraction, ammonia water reverse extraction and evaporative crystallization, and ammonium molybdate and Fe (OH) 3 are obtained. Wherein in the wet leaching process, a leaching aid and sulfuric acid are jointly used for leaching, so that Ca and Si in the oil residues are left in leaching residues, and Mo, Fe, Al and the like enter a solution. The method comprises the following steps: simultaneously extracting Mo and Fe from a solution by using an extracting agent, precipitating Fe in a Fe (OH) 3 state by using an ammonia water reverse extraction method, leaving Mo in a reverse extraction solution in the form of ammonium molybdate, and further evaporating and crystallizing the reverse extraction solution to obtain the ammonium molybdate. According to the method, two valuable metals Mo and Fe in the direct coal liquefaction oil residue can be effectively recovered, and resource recycling is facilitated.

The invention relates to a preparation method of a bismuth ferrite-based composite material. The invention aims to solve the problems of poor conductivity and few active sites of the existing bismuth ferrite electrode material, and provides a preparation method of an efficient electro-catalytic hydrogen evolution catalyst. According to the method, bismuth nitrate, ferric chloride, ethylene glycol, ammonia water, sodium hydroxide, thiourea, ammonium molybdate and cobalt nitrate are used as raw materials, a two-step hydrothermal method is adopted, the bismuth ferrite-based cobalt-doped molybdenum disulfide composite material is prepared, and the preparation method is provided for improving the electro-catalytic hydrogen evolution performance of existing bismuth ferrite.

This invention discloses a method for the efficient treatment and recovery of copper and molybdenum from high-copper-molybdenum concentrate. The method involves pre-treating low-grade high-copper-molybdenum concentrate with oxygen-pressure water leaching to remove copper. The resulting low-copper-molybdenum concentrate is then processed through oxidative roasting, alkaline leaching, extraction, and evaporation crystallization to prepare ammonium molybdate. The copper-removing solution is then subjected to synergistic extraction and stepwise back-extraction to recover copper and molybdenum. This method not only achieves efficient removal of copper from the high-copper-molybdenum concentrate, avoiding the impact of copper on molybdenum recovery and ammonium molybdate preparation, but also innovatively employs a synergistic extraction and stepwise back-extraction method to separately enrich and recover copper and molybdenum. Matching this with an electrowinning process achieves high-value copper recovery. Simultaneously, the acidic copper extraction residue and the alkaline molybdenum extraction residue are synergistically neutralized, saving reagent costs.

The invention relates to a preparation method of a niobium pentoxide loaded molybdenum disulfide catalyst and application of the niobium pentoxide loaded molybdenum disulfide catalyst in lignin conversion. The preparation method comprises the following steps: dissolving ammonium molybdate heptahydrate and thiourea in distilled water, adding Nb2O5, and adjusting the pH value of the mixture to 0.8-1.1 by using hydrochloric acid; transferring the solution into a stainless steel autoclave for hydrothermal reaction; centrifugally separating to obtain a black precipitate, washing with water and absolute ethyl alcohol, and drying in vacuum overnight; and placing the obtained substance in a high-temperature and high-pressure reaction kettle, screwing the reaction kettle to seal the reaction kettle, discharging gas after introducing H2, discharging air in the device, pressurizing to 3-5 MPa, and reacting to obtain the catalyst Nb2O5-MoS2. The catalyst shows excellent activity of aromatic phenol and ether compound hydrodeoxygenation for aromatic hydrocarbon preparation. The invention provides the catalyst which is low in cost, simple and convenient to prepare and excellent in performance, after ten cycle experiments, the activity of the catalyst is still stable, and the indexes of the conversion rate and the yield are reduced by less than 5%.

The invention discloses a special organic fertilizer for soybeans and a preparation method thereof, and belongs to the technical field of organic fertilizers. The special organic fertilizer for soybeans is prepared from the following raw materials in parts by weight: 8-10 parts of fish protein modified charcoal, 40-50 parts of decomposed soybean meal, 20-25 parts of decomposed livestock and poultry manure, 15-20 parts of humic acid, 10-15 parts of plant ash, 3-5 parts of a seaweed extract and 0.1-0.3 part of ammonium molybdate. According to the organic fertilizer, the soybean meal fermented by the trichoderma reesei and the aspergillus awamori and the fish protein modified biochar are added, the two components are compounded with the cooked livestock and poultry manure, the humic acid, the plant ash, the seaweed extract and the ammonium molybdate to form the organic fertilizer, the nitrogen fixation capacity of the soybeans is effectively improved through the synergistic effect of various substances, and the growth and development of the soybeans are remarkably promoted; the soybean yield and quality are improved. In addition, the whole organic fertilizer preparation process is free of strong acid and strong alkali treatment, the environmental pollution risk is reduced, and the standard of organic agriculture is met.

The present invention provides a method, application and product for preparing diglyceride with weight loss effect by enzymolysis, which belongs to the field of enzyme engineering technology. The method comprises the following steps: S1, mixing lipase, ammonium heptamolybdate tetrahydrate with water, adding glycerol precipitation, filtering, and obtaining an enzyme preparation; S2, mixing plant raw material oil, glycerol, fatty acid, sodium fatty acid with the enzyme preparation obtained in step S1, reacting under inert gas conditions, and obtaining an enzymolysate; S3, molecularly distilling the enzymolysate obtained in step S2 to obtain diglyceride; wherein the lipase is a mixture of Rhizomucor miehei lipase and Candida antarctica Aspergillus niger lipase. The present invention uses ammonium heptamolybdate tetrahydrate to load a specific lipase mixture, and at the same time optimizes the component types and ratios of the raw materials in the enzymolysis process, effectively improving the mass percentage content and diglyceride yield of enzymolysis production of diglyceride.

The invention provides a method for short-process all-component echelon recovery of a waste hydrogenation catalyst, and relates to the field of solid waste treatment. The recovery method of the waste hydrogenation catalyst comprises the following steps: roasting the waste hydrogenation catalyst and sodium carbonate to obtain a roasted product; the roasted product is leached with water, and leaching liquid and leaching residues are obtained; extracting the leaching solution by using an extracting agent to obtain a vanadium-molybdenum-containing organic phase, sequentially carrying out reverse extraction treatment on the vanadium-molybdenum-containing organic phase by using a strong alkaline reverse extraction agent and a weak alkaline reverse extraction agent to obtain a vanadium reverse extraction solution and a molybdenum reverse extraction solution, and carrying out vanadium precipitation treatment on the vanadium reverse extraction solution to obtain ammonium metavanadate; acidizing the molybdenum strip liquor to precipitate molybdenum to obtain ammonium molybdate; carrying out sintering treatment on the leaching residues and alkaline substances, leaching obtained calcine with water to obtain water leaching residues and filtrate, and carrying out aluminum precipitation treatment on the filtrate to obtain aluminum hydroxide, aluminum oxide or pseudo-boehmite; and reducing and smelting the water leaching residues to obtain the ferro-nickel alloy. According to the invention, multi-element comprehensive recovery of all components of vanadium, molybdenum, nickel, aluminum and sulfur can be realized, and high-value utilization of all components of the waste hydrogenation catalyst is realized.

The invention discloses a preparation method and application of a TiO2 / Ag-coated MoS2 composite photocatalyst, and relates to the technical field of catalysts.The method comprises the steps that titanium dioxide is evenly dispersed in an ethanol-water mixed solution to form turbid liquid; adding a silver nitrate solution and carrying out ultraviolet irradiation to carry out a photodeposition process; adding an ammonium tetrathiomolybdate precursor solution into the turbid liquid, carrying out ultraviolet irradiation, inducing MoS < 2-> to be subjected to an auto-oxidation reduction reaction through an electronic effect, generating an amorphous MoS2 shell on the surface of silver, and forming a core-shell Ag-coated MoS2 cocatalyst; and centrifuging, washing and drying to obtain the TiO2 / Ag-coated MoS2 composite photocatalyst. According to the Ag-coated MoS2 cocatalyst, the electron density of S atoms is higher, the strength of S (2 + delta)-Had bonds is weakened, and Had is more easily desorbed to form hydrogen; and the photocatalyst also has better light absorption and photo-generated charge separation efficiency, so that the photocatalyst shows better photocatalytic hydrogen evolution activity and stability.

The present invention provides a method for preparing high-purity molybdenum trioxide, belongs to the technical field of molybdenum trioxide production, and comprises the following steps: step S1, molybdenum ore is crushed and ground, roasted, crude molybdenum oxide is obtained, added to sodium hydroxide solution, heated and stirred, filtered, and crude sodium molybdate solution is obtained; step S2, the crude sodium molybdate solution is adjusted to pH 5.5-7.0, an exchange column of macroporous cation exchange resin is passed, and the solution pH is adjusted to 7.0-8.5, and an exchange column equipped with anion exchange resin is passed to obtain a high-purity sodium molybdate solution; step S3, excessive ammonia water is added to the high-purity sodium molybdate solution, ammonium molybdate is precipitated, washed, and dried to obtain high-purity ammonium molybdate; step S4, high-purity ammonium molybdate is put into a rotary calcining furnace, the inner wall of the furnace tube is sprayed with rare earth oxide, and a calcination mode of first heating, then cooling, and then heating is adopted to prepare high-purity molybdenum trioxide. The present invention realizes the purpose of producing high-purity molybdenum trioxide.

The invention discloses a preparation method of an ethane oxidative dehydrogenation supported catalyst. The catalyst is formed by supporting a transition metal oxide on the surface of an M1 catalyst, the preparation method of the M1 catalyst comprises the following steps: dissolving ammonium heptamolybdate tetrahydrate, ammonium metavanadate, telluric acid and a dispersing agent in deionized water to form a mixed solution; and adding an aqueous solution of niobium oxalate into the mixed solution within 15-50 minutes to form a suspension, aging, carrying out hydrothermal crystallization, drying, roasting, and removing the M2 phase to obtain the M1 catalyst. The pore structure and the specific surface area of the molybdenum-vanadium-tellurium-niobium catalyst can be improved by adding a dispersing agent in the preparation process of the M1 catalyst and limiting the time for adding an aqueous solution of niobium oxalate into a mixed solution, and through mutual cooperation of all steps and parameters, the pore structure and the specific surface area of the molybdenum-vanadium-tellurium-niobium catalyst can be improved; and then the transition metal oxide is loaded on the surface of the M1 catalyst for phase interface coupling, and the transition metal oxide and the M1 catalyst cooperate with each other, so that the catalytic performance of the loaded catalyst can be remarkably improved.

The present invention provides an environmentally friendly slow-release compound fertilizer, aiming to provide an environmentally friendly slow-release compound fertilizer with controllable release rate and high cost-effectiveness. The compound fertilizer is composed of calcium magnesium phosphate fertilizer, urea, potash fertilizer, monoammonium phosphate, borax, zinc sulfate, glycine iron, ammonium molybdate, glycine copper, liquid ammonia, sulfuric acid, liquid paraffin and a slow-release agent, wherein the potash fertilizer is one or two of potassium sulfate and potassium chloride. The present invention also provides a preparation method of an environmentally friendly slow-release compound fertilizer, comprising four steps of preliminary coating, uniform mixing, secondary coating granulation and fluidized bed reaction film formation. The slow-release agent is composed of castor oil, polyoxypropylene triol, polymerized MDI and modified silicon dioxide, and the modified silicon dioxide is obtained by specific chemical treatment. The environmentally friendly slow-release compound fertilizer has the advantages of uniform nutrient release, long effective release period, and environmental friendliness, is suitable for improving fertilizer utilization and reducing environmental pollution, and has good market application prospects.

The invention discloses a combined preparation for improving rice quality and application thereof, and belongs to the technical field of crop planting. The combined preparation is prepared from the following raw materials in parts by weight: radix angelicae sinensis, radix paeoniae alba, rhizoma atractylodis macrocephalae, fructus forsythiae, oyster mushroom bran, needle mushroom bran, a microbial agent, ammonium nitrate, potassium nitrate, ammonium molybdate, DTA-6, zinc sulfate and monopotassium phosphate. The microbial agent is prepared from bacillus megatherium, pseudomonas putida, serratia marcescens and saccharomycetes. The combined preparation for improving the rice quality is prepared by taking natural Chinese herbal medicines, fungus chaff, microbial strains and a plant growth regulator as raw materials. The combined preparation is rich in polysaccharide, amino acid, chitosan oligosaccharide and other components and active microbial agents, and can promote the growth and development of rice and improve the quality of rice. The combined preparation provided by the invention provides a new technical thought for rice quality improvement.

The present invention provides a method for producing a molybdenum-vanadium-aluminum-chromium alloy with high uniformity. The composition of the molybdenum-vanadium-aluminum-chromium alloy is as follows: Mo 25% - 28%, V 24% - 27%, Cr 28% - 31%, with the balance being Al, O ≤ 0.05%, C ≤ 0.05%, and the segregation of the main content being < 0.6%. It relates to the field of metallurgical technology. The technological steps are as follows: (1) Prepare an ammonium molybdate-ammonium dichromate-ammonium metavanadate precursor by hydrothermal method using sodium molybdate, sodium metavanadate, sodium dichromate, and ammonium chloride; (2) Perform high-temperature treatment on the precursor to obtain a MoO3 / V2O5 / CrO3 composite material; (3) Mix the MoO3 / V2O5 / CrO3 composite material, refined aluminum powder, and calcium oxide in proportion, load them into a furnace and ignite to undergo a thermite reaction to obtain a molybdenum-vanadium-aluminum-chromium alloy ingot. Compared with the molybdenum-vanadium-aluminum-chromium alloy produced by the traditional thermite method, the uniformity of the present invention is greatly improved, and it can be used for the production of titanium alloys such as TB2, TB9, TB15, and TB16.

The invention discloses a preparation method and application of a composite hydrogen evolution catalyst for in-situ growth of MoS2 on a Ti3C2Tx ultrathin nanosheet, relates to a preparation method and application of a hydrogen evolution catalyst, and aims to solve the technical problems of low utilization rate of active sites and low catalytic efficiency of the conventional MoS2 catalyst. The method comprises the following steps: etching titanium aluminum carbide to obtain Ti < 3 > C < 2 > F < x > powder; stripping the powder or performing alkali heat treatment, vulcanization or hydro-thermal treatment after stripping to prepare an ultrathin nanosheet; the ultrathin nanosheets and a mixed solution of ammonium heptamolybdate tetrahydrate and thiourea are subjected to a hydrothermal reaction, separation, washing and drying are carried out, the composite hydrogen evolution catalyst MoS2 / Ti3C2Tx is obtained, and T is F, S, O or OH. When the composite material is used for producing hydrogen by electrolyzing water, the current density of 10mA. Cm <-2 > can be realized only by virtue of 86-97mV overpotential in alkaline electrolyte, and the composite material is used in the field of producing hydrogen by electrolyzing alkaline water.

The application relates to the field of fireproof bricks, and discloses a baking-free fireproof brick and a preparation method thereof. The baking-free fireproof brick comprises iron tailings, cement, fly ash, a functional additive, fine aggregate, quartz sand, a chromium aluminum phosphate binder, a water reducing agent and water. The functional additive is prepared by using aluminum chloride hexahydrate and alkaline silica sol as raw materials, ammonium molybdate tetrahydrate as a catalyst, growing mullite whiskers on the surface of silicon carbide fibers through vacuum impregnation and heat treatment, modifying the prepared composite silicon carbide fibers through 3-(methacryloxy) propyl trimethoxysilane, and then copolymerizing the modified composite silicon carbide fibers with acrylic acid and 4-hydroxybutyl vinyl ether. The chromium aluminum phosphate binder is prepared by using aluminum hydroxide, phosphoric acid and chromium trioxide as raw materials and calcium hydroxide as a curing agent. The baking-free fireproof brick prepared through the synergistic effect of the components has high compressive strength and bending strength, small water absorption and good baking-free fireproof and heat insulation performance.

The invention discloses a method for preparing hydrogen peroxide through ultralow-temperature photocatalysis. The method comprises the following steps: adding a photocatalytic material into water or a solution, completely dispersing, and adjusting the pH value to obtain a reaction solution; o2 is added into the reaction solution until saturation, and a light source is turned on for a photocatalytic reaction; after the reaction is finished, detecting the concentration of H2O2 by adopting a potassium iodide-ammonium molybdate spectrophotometric method; the photocatalytic material is a semiconductor metal oxide; the temperature of the photocatalytic reaction is-5 to-60 DEG C. According to the method, the catalyst and oxygen are concentrated in micron-sized intergranular water in an ultralow-temperature state, so that the reactant concentration is greatly improved, and hydrogen peroxide generated by catalysis can be quickly desorbed in the ultralow-temperature state, and the decomposition reaction of the hydrogen peroxide can be inhibited, so that the unit mass of the catalyst and the production quantity of the hydrogen peroxide in unit time are remarkably improved.

The invention discloses a metal-doped nitride heterojunction catalyst, a preparation method thereof and application of a lithium / sodium-sulfur battery, and belongs to the field of alkali metal sulfur-based battery electrocatalyst materials. The preparation method comprises the following steps: (1) dissolving cobalt nitrate, ammonium molybdate, ammonium chloride and urea in deionized water according to a molar mass ratio of 12.8: 1.6: 8: 8; (2) heating in an oil bath at 100 DEG C for 2 hours in an argon atmosphere to obtain a purple clear solution; and (3) centrifugally washing the precipitate with deionized water for three times, freeze-drying to obtain a purple floccule, and calcining the purple floccule in a mixed atmosphere of ammonia gas and argon gas in a ratio of 1: 4 at 700 DEG C for 3 hours to obtain the metal-doped nitride heterojunction catalyst. The method is low in production cost and simple in manufacturing process, and the catalytic material has the advantages of high energy density, long cycle life and the like when applied to lithium / sodium-sulfur batteries.

The invention relates to the technical field of production and preparation of ammonium tetramolybdate, and particularly discloses a preparation method for producing high-purity ammonium tetramolybdate from low-grade molybdenite. The preparation method for producing the high-purity ammonium tetramolybdate from the low-grade molybdenite comprises the following steps: S1, pretreating the low-grade molybdenite to obtain slag, and roasting the slag to obtain roasted slag; s2, the roasted slag and an ammonia water solution are mixed and leached, and a leaching solution is obtained; s3, an impurity removal agent and an adsorbent are added into the leachate for adsorption and purification, the impurity removal agent comprises mercaptoacetic acid and disodium ethylene diamine tetraacetate, the adsorbent is modified calcium alginate, and after purified liquid passes through an anion exchange resin column, an ammonium molybdate solution is obtained; and S4, adding a nitric acid solution into the ammonium molybdate solution, adjusting the pH value, and then crystallizing to obtain high-purity ammonium tetramolybdate. According to the preparation method, the purity of the ammonium molybdate solution is effectively improved through three procedures, and then the purity of ammonium tetramolybdate prepared from low-grade molybdenite is effectively improved.

The invention relates to the technical field of catalysts, in particular to a graphene-based desulfurization catalyst and a preparation method thereof. Graphene oxide is used as a carrier, an initiating group is introduced firstly, a short-brush amphoteric polymer gradient modification layer and a long-brush amphoteric polymer gradient modification layer are sequentially constructed through atom transfer radical polymerization, ammonium molybdate-urea complex deposition is fused, and uniform nucleation of a metal precursor is achieved. Two-stage vulcanization is adopted in the preparation process, the crystallization process of a precursor is controlled step by step at different temperatures, and the size and dispersity of a molybdenum disulfide sheet layer are optimized. The catalyst is high in conversion rate under a hydrodesulfurization model system, low in total sulfur of discharged materials, and excellent in activity retention rate after multiple cycles. The method can be widely applied to the field of fuel oil deep desulfurization, and the efficient and environment-friendly industrial catalysis requirement is met.

The invention discloses a bio-oil enhanced hydrodenitrogenation method, which comprises the following steps: adding bio-oil, a catalyst, formic acid and deionized water into a reaction kettle, uniformly stirring to obtain a mixed solution, continuously stirring for reaction, and after the reaction is finished, carrying out suction filtration and distillation to obtain reformed bio-oil. The preparation method of the catalyst comprises the following steps: mixing corn straw and ammonium molybdate, adding deionized water after mixing, stirring and dipping, and then carrying out vacuum drying and calcining to obtain the catalyst. In the catalytic reforming process, formic acid is innovatively introduced to serve as a hydrogen source, the gas-liquid interface transmission resistance of a traditional gaseous hydrogen source is eliminated through the homogeneous hydrogen supply characteristic of liquid formic acid, the flammable and explosive risk of high-pressure hydrogen is avoided, the process safety is improved, meanwhile, formic acid is subjected to in-situ decomposition on the surface of the catalyst to generate active hydrogen species, and the catalytic reforming efficiency is improved. And a synergistic catalysis mechanism is formed with a platinum-like active site of the catalyst, so that the kinetic advantage of the hydrodenitrification reaction is enhanced, and an efficient, safe and environment-friendly bio-oil hydrodenitrification process system is constructed.

The invention discloses a high-speed extruded low-smoke halogen-free flame-retardant polyolefin material for a remote optical cable and a preparation method thereof. The polyolefin material is prepared from the following raw materials in parts by weight: 15 to 30 parts of ethylene-vinyl acetate copolymer, 5 to 8 parts of SEBS flame-retardant master batch, 8 to 11 parts of low-density polyethylene, 5 to 8 parts of maleic anhydride grafted polyethylene, 5 to 10 parts of magnesium hydroxide, 1 to 3 parts of synergistic flame retardant, 30 to 45 parts of calcium carbonate, 0.1 to 0.5 part of antioxidant and 1 to 2 parts of lubricant, the synergistic flame retardant is a shape memory microencapsulated flame retardant, and a core material of the synergistic flame retardant is a flame-retardant compound containing red phosphorus and ammonium molybdate. The polyolefin material disclosed by the invention has excellent flame retardant property, good mechanical property and flexibility and excellent chemical resistance and weather resistance, and can meet the requirements of a high-speed extrusion process.

The invention relates to the technical field of molybdenum powder preparation, in particular to superfine molybdenum powder and a preparation method thereof.The preparation method comprises the steps that ammonium molybdate is subjected to ball milling and sieving to obtain ammonium molybdate powder, and the ammonium molybdate powder and a gluconic acid solution are mixed, stirred and dissolved to obtain a suspension solution; adding an azeotropic solution of n-butyl alcohol and water into the suspension solution, heating, stirring and dissolving to obtain a mixed solution; distilling the mixed solution, and cooling after the mixed solution is evaporated to obtain a solid ammonium molybdate precursor; the preparation method comprises the following steps: dispersing an ammonium molybdate precursor in an azeotropic solution, heating and roasting the ammonium molybdate precursor in air to obtain MoO3, carrying out first-stage reduction on the MoO3 in a hydrogen atmosphere to obtain MoO2, and then carrying out second-stage reduction to obtain the super molybdenum powder. And meanwhile, by regulating and controlling the mixing ratio of ammonium molybdate and the azeotropic solution, the morphology and size of the molybdenum powder can be remarkably adjusted, so that the molybdenum powder which is single and regular in morphology, uniform in distribution, high in yield, simple in preparation process and capable of being rapidly produced on a large scale is prepared.