832 results about "Hydrogen oxidation" patented technology

A method for recovering nickel from an sulfuric acid aqueous solution, for recovering nickel in an effectively utilizable form as a raw material of nickel industry material, by separating efficiently impurity elements of iron, aluminum, manganese and the like, from the sulfuric acid aqueous solution containing nickel and cobalt, and the impurity elements, iron, aluminum, manganese and the like.

The method is characterized by comprising the following steps (1) to (5).

• • step (1): to subject the sulfuric acid aqueous solution to oxidation neutralization treatment.
  • step (2): then, to subject the solution to neutralization treatment, and to separate and recover mixed hydroxides containing nickel and cobalt.
  • step (3): to subject the mixed hydroxides to dissolution treatment in a sulfuric acid solution having a concentration of equal to or higher than 50% by mass.
  • step (4): to subject the concentrated solution to solvent extraction treatment, using a phosphate ester-based acidic extraction agent.
  • step (5): by adding a neutralizing agent to the resultant extraction residual liquid, to subject the solution to the neutralization treatment, and to separate and recover nickel hydroxide generated.

A method for making a membrane electrode assembly includes the steps of providing a membrane electrode assembly including an anode including a hydrogen oxidation catalyst; a cathode; a membrane disposed between the anode and the cathode; and depositing a peroxide decomposition catalyst in at least one position selected from the group consisting of the anode, the cathode, a layer between the anode and the membrane and a layer between the cathode and the membrane wherein the peroxide decomposition catalyst has selectivity when exposed to hydrogen peroxide toward reactions which form benign products from the hydrogen peroxide. The peroxide decomposition catalyst can also be positioned within the membrane. Also disclosed is a power-generating fuel cell system including such a membrane electrode assembly, and a process for operating such a fuel cell system.

The invention discloses a gahnitem, zinc oxide and nickel zinc nano-composite photocatalytic material which has a high specific surface area and a mesoporous structure and is prepared by roasting at high temperature by taking ternary hydrotalcite as a precursor. The material is used for the adsorption and the degradation of organic pollutants. The photocatalytic material is prepared by taking zinc nitrate, nickel nitrate, aluminum nitrate, sodium carbonate, sodium hydroxide and the like as raw materials; preparing the raw materials into salt solutions and alkali solutions respectively; mixing the solutions by using a constant-flow pump at the temperature of 80 DEGC with magnetic stirring, transferring the mixed solution into a hydrothermal reaction kettle; performing hydrothermal treatment at 130 to 180 DEG C; performing suction filtration, washing and drying to the precursor; roasting the precursor in Muffle furnace for 2 to 6 hours at the temperature of 400 to 600 DEG C to obtain the product, wherein the specific surface area is greater than 150 m<2>.g<-1>. The photocatalyst disclosed by the invention has regular shape, large specific surface area, and super-high capacity for adsorbing and degrading organics, and can be reused; the raw materials for preparing the composite photocatalyst are abundant, the cost is low, and the process is simple.

The invention discloses a preparation method of a ternary anode material precursor. According to the preparation method, an intermediate product namely nickel-manganese-cobalt hydroxide concentrate generated by producing electrolytic nickel from laterite, and the preparation process comprises the following process flows: A, acid leaching; B, impurity removal and recrystallization; C, preparation of a mixed salt; D, preparation of a precipitant; E, synthetic reaction; F, adjustment of the pH value; G, separation and washing; H, drying. The ternary anode material precursor prepared by the preparation method disclosed by the invention is uniform in particle size distribution, high in activity, high in density, high in specific capacity and low in cost.

A composite hydrogen storage material including 1) an active material having hydrogen storage capacity; and 2) a catalytic material having greater catalytic activity toward the dissociation of molecular hydrogen and/or oxidation of hydrogen than that of said active material having hydrogen storage capacity. Also, a fuel cell employing anodes formed from the composite hydrogen storage material. The fuel cell has the ability to start up instantly and can accept recaptured energy such as that of regenerative braking by operating in reverse as an electrolyzer.

The invention relates to an environmental-friendly comprehensive utilization method for a laterite-nickel ore, which comprises the following steps of: (1) grinding the laterite-nickel ore, mixing with sulfuric acid, roasting, dissolving out roasted clinker and filtering to obtain silicon dioxide and dissolution liquid; (2) deironing the dissolution liquid to obtain liquid No.2 and filter residue (iron compounds), wherein the liquid No.2 comprises aluminum, nickel and magnesium and can be treated by the step (3) or (4); (3) precipitating the aluminum in the liquid No.2 by using alkali, filtering, precipitating the nickel in filtrate by using sodium sulfide, filtering, precipitating the magnesium by using the alkali, and treating filter residue to obtain aluminum oxide, nickel hydroxide, nickel sulfide and magnesium oxide respectively; and (4) precipitating the aluminum and the nickel in the liquid No.2 by using the alkali, treating mixed slag containing the aluminum and the nickel by using the alkali to obtain aluminum hydroxide and nickel hydroxide products, and precipitating the magnesium in filtrate subjected to aluminum and nickel precipitation by using ammonia or ammonium saltto obtain a magnesium oxide product. The method is suitable for treating various laterite-nickel ores, three wastes (waste gas, waste water and waste residue) are not generated, and valuable components magnesium, nickel, iron, aluminum and silicon in the laterite-nickel ore are separated and extracted.

The nickel hydroxide particles for a nickel hydroxide electrode may be treated using an alkaline solution of a strong oxidizing agent such as sodium or potassium persulfate to modify the surface nickel hydroxide structure. The resulting modified surface structure has been found to impart various benefits to electrodes formed from the nickel hydroxide. It is believed that the oxidation of cobalt compounds at the surface of the nickel hydroxide particles results in a highly conductive cobalt compound that plays an important role in the high reliability, high stability and high capacity utilization of nickel electrodes as described herein.

The invention relates to a preparation method of thin-shelled noble metal catalyst, and mainly solves the problems of the prior art of high dosage, poor selectivity and short service life of noble metal. The preparation method better solves the technical problems of the prior art by adopting the technical proposal comprising the following steps of: (a) coating the slurry of a coat porous material on the inner core of an inert carrier, drying the slurry coating and baking the slurry coating at a temperature of between 700 and 1,200 DEG C for 0.5 to 10 hours to obtain a laminar composite carrier; (b) impregnating the surface of the laminar composite carrier with a solution containing noble metal and cocatalyst components, drying the laminar composite carrier, and baking the laminar composite carrier in the air at a temperature of between 200 and 700 DEG C for 1 to 24 hours to obtain a thin-shelled catalyst precursor; and (c) reducing the thin-shelled catalyst precursor in a reducing atmosphere at a temperature between 300 and 800 DEG C for 1 to 24 hours to obtain the thin-shelled noble metal catalyst. The preparation method can be used in the industrial production of gas purification materials which are dehydrogenation-deoxidization catalysts, alkanes and aromatic hydrocarbons for selective hydrogen oxidation in a dehydrogenation process.

A method for treating nitrate-contaminated water comprising treating said water with hydrogen-oxidizing denitrifying bacteria in the presence of hydrogen. The apparatus for use in this method preferably comprises:

• • (a) a pure culture of autotrophic, hydrogen-oxidizing denitrifying bacteria;
  • (b) a hydrogen generator;
  • (c) a flow-through bioreactor; and
  • (d) a filtration unit.

The invention relates to a high-purity iron oxide black pigment and a production method thereof. The production method comprises the following steps of: with a crystal seed as a carrier in a liquid phase method production process, carrying out reaction on ferrous sulphate and sodium hydroxide in an oxidation barrel, immediately generating ferrous hydroxide sol under the alkali condition, introducing steam and warming for reaction, introducing air for oxidation after a specified temperature is reached, and reacting for a period of time to obtain the high-purity iron oxide black pigment. The granules of the product obtained by the method are small and uniform compared with a synthetic method, and the yield is high and the coloured light is good; meanwhile, the purity of the product is controlled, thus the operating requirement in the industry is met. The invention also aims at providing the high-purity iron oxide black pigment prepared by adopting the method.

The present invention relates to composite electrode materials, a preparation method thereof, and an application thereof. The method comprises: metallic oxide and/or hydroxide solution through coordination solution are mixed with carbon materials, the metallic oxide and/or metal hydroxide are grown in situ at the surface of the carbon materials through evaporation of a ligand solution, and the composite electrode materials are obtained. The method provided by the invention is simple to operate, low in cost, green and environmentally friendly without postprocessing, and provides possibility for industrialization large-scale production of the electrode materials. The composite electrode materials prepared by the method are good in electric energy storage. For example, the 5% capacity nickelous hydroxide-active carbon composite electrode materials are prepared by the method, the full electrode quality specific capacity thereof can reach 294F/g, and the active substance specific capacity thereof can reach 4917F/g.

In solid polymer electrolyte fuel cells, an oxygen evolution reaction (OER) catalyst may be incorporated at the anode along with the primary hydrogen oxidation catalyst for purposes of tolerance to voltage reversal. Incorporating this OER catalyst in a layer at the interface between the anode's primary hydrogen oxidation anode catalyst and its gas diffusion layer can provide greatly improved tolerance to voltage reversal for a given amount of OER catalyst. Further, this improvement can be gained without sacrificing cell performance.

The invention discloses a method for preparing nanometer nickel oxide and application of the method. The method includes adding a certain quantity of inorganic salt and organic liquor into aqueous liquor to be used as electrolyte; using metal nickel as an electrode; applying voltage to two ends of the electrode; forming nickel hydroxide nano-particles by means of regulating the concentration of the electrolyte, the amplitude of the voltage, the reaction time and the stirring speed; then annealing the nickel hydroxide nano-particles at the temperature of 300 DEG C; and obtaining the nickel hydroxide nano-particles. A formaldehyde sensor built on the basis of the nanometer nickel oxide can be used for detecting formaldehyde gases with different concentrations. The method has the advantages that the nanometer nickel oxide is prepared in the electro-chemical method the nanometer nickel oxide is used for building the formaldehyde sensor, a process is simple, operation is convenient, environmental pollution is prevented, the cost of a product is low, repeatability is good, and the method is applicable to large-scale industrial production.

The invention belongs to the technical field of metal electrocatalysts, and provides a preparation method and application of a nitrogen-doped carbon-supported metal nano-particle electrocatalyst withuniform particle size for alkaline hydroxidation reaction. The nitrogen-containing ligand and the carbon material are used as the nitrogen source and the carbon source, the nitrogen-doped carbon carrier contains more metal nanoparticle attachment sites is simply and quickly prepared through carbonization. As the metal salt is adsorbed in advance and the reduction temperature of the metal salt is controlled, the purpose of control the reduction rate of the metal salt is achieved, and the metal nanoparticles are uniformly dispersed on the carrier. A surfactant is not used in the invention, and the reagent used is safe and harmless. The preparation process of the invention is simple and easy, the synthesis cost is low, and the large-scale production is easy. The supported highly dispersed nano-electrocatalyst prepared by the invention has high electrocatalytic activity and is suitable for alkaline fuel cell anodic hydrogenation reaction.

The invention belongs to the technical field of metal electrocatalysts, and relates to a preparation method of a low-platinum metal spherical nanoparticle electrocatalyst with uniform nitrogen-doped carbon supported particle size and an application. The method comprises the following steps: dispersing platinum metal salt, M metal salt and a nitrogen-containing ligand into a solvent, and performingultrasonic treatment to obtain a uniform solution; putting the uniform solution into a water bath, and performing stirring at 20-90 DEG C; adding a carbon carrier dispersed in the solvent, carrying out ultrasonic treatment, performing stirring at 20-120 DEG C, and evaporating the solvent to dryness to obtain a black mixture; after drying and grinding, performing carbonizing for 0.1-3 hours at thetemperature of 200-1100 DEG C in an inert atmosphere; changing inert gas into reducing gas, and etching precipitates attached to the surfaces of the metal particles. According to the preparation method disclosed by the invention, a surfactant does not need to be used, and the prepared nitrogen-doped carbon-supported low-platinum metal spherical nanoparticle electrocatalyst with uniform particle size has higher electrocatalytic activity and is suitable for an anodic hydrogen oxidation reaction of a hydroxyl exchange membrane fuel cell.

The invention relates to a mesoporous manganese oxide nano material and a preparation method thereof. In the invention, a uniformly distributed mesopore with the aperture of 2 to 10 nanometers and a mixture of oxyhydrogen manganese oxide and manganic manganous oxide or a mangano-manganic octoxide monocrystal granule or a manganese sesquioxide monocrystal granule with the granule particle diameter controlled within the range of 20 to 80 nanometers are prepared by the hydrothermal function of manganese metal, manganese acetate and ammonia and the subsequent calcination control, and the uniformly distributed mesoporous, the mixture of oxyhydrogen manganese oxide and manganic manganous oxide, the mangano-manganic octoxide monocrystal granule and the manganese sesquioxide monocrystal granule play a catalytic action to a toluene combustion reaction. The invention has simple preparation method, loose synthesizing condition, easy repetition and cheap raw materials and can carry out large-scale production.

The invention discloses a preparation method of a carbon and nitrogen doped niobium (V) pentoxide nano sheet and an application of the nano sheet as a photocatalyst. The preparation method comprises the following steps: weighing soluble niobium salt at a room temperature, adding anhydrous ethanol to form an ethanol solution of niobium salt, dropwise adding an organic ammonium hydroxide solution into the ethanol solution of niobium salt, wherein in the initial phase, white turbidity appears, keeping on adding the organic ammonium hydroxide solution until the white turbidity disappears so as to form a clear and transparent solution; transferring the obtained solution to a hydrothermal reactor, wherein the solution accounts for 50 to 70% of the volume of the hydrothermal reactor, carrying out hydrothermal reactions at a temperature of 100 to 280 DEG C, after reactions, naturally cooling the reactor to the room temperature, washing and drying the reaction product to obtain white powder; and burning the white powder for 2 to 12 hours at a temperature of 400 to 1200 under the protection of nitrogen gas so as to obtain the carbon and nitrogen doped niobium (V) pentoxide nano sheet. The invention also discloses an application of the carbon and nitrogen doped niobium (V) pentoxide nano sheet as a photocatalyst. The photocatalyst can be applied to benzyl alcohol oxidation to prepare benzaldehyde.

An object of the present invention is to provide an organosol for forming a coating that can remain hydrophilic for a long time even in a situation with no exposure to light, and a manufacturing method thereof. As a means for solving this problem, the organosol is created by dispersing magnesium fluoride compound obtained by reacting at least a magnesium compound (the main raw material) with a solution containing hydrogen fluoride, in an organic solvent. The organosol is characterized by containing fine particles of the magnesium fluoride compound which particles have an average particle diameter of from 5 to 500 nm.

The invention discloses a catalyst for preparing a multi-carbon product by electro-reduction of carbon dioxide and carbon monoxide as well as a preparation method and application thereof, and belongsto the field of electro-catalysis. The catalyst is a halogen-modified copper electro-catalyst, and halogen comprises at least one of fluorine, chlorine, bromine and iodine. The preparation method of the catalyst comprises the following steps: loading a copper halide precursor on a gas diffusion layer, and carrying out electric reduction to obtain the halogen-modified copper electro-catalyst, wherein the copper halide precursor comprises at least one of a fluorine copper hydroxide precursor and other copper halide precursors except the fluorine copper hydroxide precursor. The catalyst is applied to a reaction for preparing a multi-carbon product by electrically reducing carbon dioxide and carbon monoxide, is high in reaction activity, high in selectivity and stable in catalytic performance,and maintains very high multi-carbon product selectivity in a very wide current range.

The invention relates to a method for preparing nano nickel bicarbonate, which comprises the following steps of: adding water into urea or urotropine for dissolving, adding nickel salt or nickel hydroxide and stirring, wherein the mole ratio of the urea or the urotropine to nickel is 1:1-16:1, and the concentration of the nickel salt in solution is 0.1-1.0mol/L; shifting the obtained solution into a hydrothermal reactor; after reacting at 90-240 DEG C for 1-96 hours, cooling; and filtering obtained reaction mixed liquid, washing with distilled water and anhydrous ethanol and placing in a vacuum drying box at 60 DEG C for drying to obtain a cubic phase nano nickel bicarbonate square block with the size of 100nm or so. The invention uses the urotropine or the urea as a precipitator, NH3 andCO2 generated by the precipitator dissolve nickel hydroxide, and the pure cubic phase Ni(HCO3)2 nano crystal is prepared finally.

The invention belongs to the technical field of electrochemical catalysis, and particularly relates to a platinum-based catalyst as well as a preparation method and application thereof. The platinum-based catalyst comprises a nitrogen-containing carbon carrier and platinum atoms loaded on the nitrogen-containing carbon carrier, and belongs to a loaded catalyst. The nitrogen-containing carbon carrier has good electrical conductivity, so the high-content nitrogen element is doped, the adsorption, the coordination and the anchoring of platinum atoms are easily achieved, the platinum atoms are uniformly distributed on the nitrogen-containing carbon carrier in a single atom state, the high dispersibility is provided, the agglomeration phenomenon cannot be generated, the platinum utilization rate in the platinum-based catalyst can be improved during the catalysis process, the platinum loading capacity is reduced, and the obtained platinum-based catalyst has advantages of low platinum and high efficiency. Meanwhile, the platinum-based catalyst disclosed by the invention has dual activities of catalyzing hydrogen evolution and hydrogen oxidation, and has a good application prospect.