504 results about "Hydrogen oxidation" patented technology

The invention provides a dump leaching method for improving the leaching rate of gold ore, and belongs to the technical field of mineral processing. The method comprises the following steps: firstly, separating minerals into oversize products and undersize products; mixing sodium carboxymethyl cellulose, bentonite and ferrous sulfate to obtain a mixture, and granulating the undersize product by using the mixture as a binder; and mixing the undersize product particles with the oversize product, and carrying out cyanide-free dump leaching. According to the method, through graded granulation and heap building, the problem that heap building permeability is poor due to the fact that the gold ore contains many clay minerals is solved. In the granulation stage, ferrous hydroxide colloid generated by hydrolysis of ferrous sulfate in the binder can assist ore particle agglomeration, and particle stability is enhanced; during subsequent cyanide-free dump leaching, ferrous sulfate can be used as an auxiliary reducing agent and a catalyst in a thiourea gold leaching system to promote oxidation and dissolution of gold; meanwhile, ferrous ions can adjust the oxidation-reduction potential of a system, so that the thiourea gold leaching reaction is in a more favorable potential interval, the oxidation efficiency of thiourea is improved, invalid decomposition of thiourea is reduced, and therefore the use amount of thiourea and the use amount of agents are reduced.

The invention relates to a preparation method of a multi-site silver (Ag) and nickel hydroxide (Ni (OH) 2) modified copper (Cu) nanowire catalyst (Ag-Ni (OH) 2) / Cu NW) and application of the multi-site silver (Ag) and nickel hydroxide (Ni (OH) 2) modified copper (Cu) nanowire catalyst. A cation exchange and electrodeposition method is adopted to prepare an electrocatalytic nitrate reduction reaction NO3-RR series catalyst with three sites of Ag, Ni (OH) 2 and Cu. Based on the synergistic effect of three sites, Ag in the catalyst promotes conversion from nitrate NO3 <-> to nitrite NO2 <->, Ni (OH) 2 promotes dissociation of water H2O to generate free hydrogen * H, Cu atoms near Ni (OH) 2 accelerate conversion from NO2 <-> to ammonia NH3, and the efficient series catalytic process is achieved. Under the condition of-0.1 V vs. Reversible hydrogen electrode RHE in a 1M potassium hydroxide solution containing 50 mM of potassium nitrate, the NH3 yield of 4.01 mgh <-1 > cm <-2 > and the NH3 Faraday efficiency of 97.3% are obtained, under the condition of 0V vs. RHE, the excellent energy efficiency of 46.5% is achieved, the excellent catalytic activity is kept in a NO3 <-> solution with the wide concentration, and the good sewage treatment capacity is achieved. The invention provides a new design thought for tandem catalysis, and has a wide application prospect in the field of NO3-RR.

The invention belongs to the technical field of electrochemistry, and provides a monatomic iridium-based alloy cluster catalyst and a preparation method and electrocatalysis application thereof, and the preparation method comprises the following steps: low-pressure gas-phase capillary filling: mixing an iridium organic metal precursor, a dopant metal organic precursor, a microporous carrier material and a solvent, and drying to obtain mixed powder, the mixed powder is placed in an ampoule bottle with a certain vacuum degree and sealed, then the ampoule bottle is placed in a rotary drying oven for high-temperature heat treatment, and powder a is obtained; temperature-controlled acid etching: mixing the powder a and an acid solution for reaction in the environment of protective gas to obtain black powder; the black powder is placed in H2 / Ar mixed gas for programmed heat treatment, and the monatomic iridium-based alloy cluster catalyst is obtained. The monatomic iridium-based alloy cluster catalyst prepared by the method provided by the invention shows mass activity and catalytic durability which are obviously superior to those of commercial platinum carbon in alkaline hydroxide catalysis, and has a practical application prospect.

The invention relates to a dephosphorization material, a preparation method thereof and a dephosphorization method, belongs to the field of water treatment, and solves at least one of the problems of contradiction between adsorption capacity and structural stability, fast capacity fading, short service life, difficult recovery, higher cost and the like of the existing lanthanum-based dephosphorization material. The phosphorus removal material is a nano-porous carbon-supported lanthanum composite material, and comprises an amorphous nano-porous carbon matrix, an amorphous nano-porous carbon carrier, an amorphous nano-porous carbon carrier, and an amorphous nano-porous carbon carrier, and an active component embedded in situ in the nanoporous carbon matrix; wherein the active component comprises lanthanum oxide and / or lanthanum hydroxide. According to the invention, the adsorption capacity is high, the structure is stable, the attenuation of the adsorption capacity is delayed, the service life is prolonged, the cost is reduced, and the adsorbent can be recycled.

The invention discloses a method for preparing a sulfur-doped nickel hydroxide-based self-supporting electrolyzed water anode, and belongs to the technical field of preparation of electrolyzed water catalytic electrodes, and the method comprises the following steps: S1, preparing strong oxidizing salt, thiourea and transition metal salt into an active solution; s2, pretreating the nickel-containing metal substrate to obtain a precursor; and S3, immersing the precursor in an active solution for ultrasonic impregnation, and performing in-situ oxidation to prepare the sulfur-doped nickel hydroxide-based self-supporting electrolytic water anode. According to the method for preparing the sulfur-doped nickel hydroxide-based self-supporting electrolytic water anode, an oxidizing agent-thiourea-transition metal salt synergistic reaction system is adopted, an ultrasonic-assisted technology is combined, and a high-performance catalytic layer is directly grown on the surface of the metal substrate in situ at room temperature; the invention aims to synchronously realize high catalytic activity, excellent stability and macro preparation of the electrode and fundamentally solve the core pain points of long process, high energy consumption, difficulty in amplification and the like in the prior art.

The invention provides a waste molybdenum-based catalyst regeneration method which comprises the following steps: crushing and grinding a waste molybdenum-based catalyst to obtain catalyst powder; adding a liquid caustic soda solution into the obtained catalyst powder, and placing in a reaction kettle for hydrothermal reaction to obtain molybdenum hydroxide and sodium sulfate; the obtained molybdenum hydroxide is sequentially subjected to drying treatment, forming treatment and calcining treatment, and the regenerated catalyst is obtained. According to the present invention, the poisoning catalyst is regenerated by mainly using the hydrothermal reaction principle, such that the catalyst cost can be reduced, and the operation cost caused by other waste catalyst recovery methods can be avoided, such that the regeneration of the catalyst active component is achieved through the multi-stage staged treatment so as to significantly improve the regeneration efficiency and the regeneration frequency; and a new technical path is provided for resource utilization of the waste molybdenum-based catalyst.

The invention belongs to the field of PET (polyethylene glycol terephthalate) plastic waste treatment, and particularly relates to preparation of a copper oxide-nickel hydroxide core-shell structure catalytic material and application of the copper oxide-nickel hydroxide core-shell structure catalytic material to preparation of high-added-value formic acid by upgrading electro-catalysis PET plastics, and the preparation method comprises the following steps: (1) placing a copper conductive substrate in an alkali etching mixed solution for alkali etching treatment, obtaining a conductive substrate on which a Cu (OH) 2 precursor grows; (2) placing the conductive substrate on which the Cu (OH) 2 precursor grows in a muffle furnace for heat treatment to obtain a conductive substrate on which CuO nanowires grow; and (3) placing the conductive substrate on which the CuO nanowire grows in a hydrothermal kettle, and obtaining the CuO-coated Ni (OH) 2-x core-shell structure catalyst through a hydrothermal method.

A hybrid electrochemical device configuration that comprises a first electrode that includes a redox reactive material or an alloy based on a transition metal, a second electrode that includes a multi-functional catalyst to catalyze hydrogen evolution reaction, hydrogen oxidation reaction, and water oxidation reaction at the second electrode, a separator disposed between the first and second electrode, an electrolyte disposed between the first electrode and the second electrode, and a conduit which provides the means to compensate for water loss in the electrolyte during electrochemical device operation. At least one valve is included that connects the electrolyte management system to the conduit system and a valve to connect the gas formed in the electrode to the gas management system. The electrochemical device configurations include several individual devices stacked on top of each other and separated from each other using separation plates.

The invention relates to the field of preparation of nano materials, in particular to a preparation method of a metal-oxide cluster electro-catalytic material based on an ammonia-mediated electrostatic adsorption principle, and aims to solve the problem that a metal-oxide cluster heterogeneous interface is difficult to accurately construct by an existing method. The preparation method comprises the following steps: dispersing a carbon carrier, a soluble inorganic compound containing platinum, ruthenium and rhodium, a soluble metal complex anion salt and dopamine hydrochloride in a water-alcohol mixed solution, adding ammonia water, and preparing a metal-oxide heterogeneous cluster precursor through an ammonia-mediated electrostatic adsorption effect; and pyrolyzing the precursor in a reducing atmosphere to prepare the metal-oxide cluster electro-catalytic material. The prepared electro-catalytic material has a definite heterogeneous cluster interface and has excellent performance in alkaline hydroxide reaction. The method is simple and convenient to operate, low in cost and low in energy consumption, can be popularized to various metal-oxide cluster electro-catalytic materials, and has application potential.

The invention relates to the technical field of electro-catalysis, in particular to a Cu-In2O3 nanoparticle catalyst as well as a preparation method and application thereof. The method comprises the following steps: dissolving a soluble copper salt and a soluble indium salt in water together, mixing with an alkali solution, carrying out a precipitation reaction, and combining copper ions and indium ions with OH <-> ions in alkali in the precipitation reaction process to generate copper hydroxide and indium hydroxide so as to obtain a precipitate; freeze-drying the precipitate to obtain a precursor; and calcining the precursor in a mixed atmosphere of hydrogen and inert gas to obtain the Cu-In2O3 nanoparticle catalyst. The Cu-In2O3 nanoparticle catalyst disclosed by the invention not only has excellent catalytic activity and high selectivity to formic acid, but also has good stability and reusability. When the Cu-In2O3 nano-particle catalyst is applied to the electrocatalytic carbon dioxide reduction reaction, the energy consumption can be effectively reduced, and the production efficiency and the product quality of formic acid can be improved.

The invention belongs to the technical field of anion exchange membrane fuel cells, and discloses a high-stability ruthenium-based hydroxide electrocatalyst used as an anode of an anion exchange membrane fuel cell and a preparation method of the high-stability ruthenium-based hydroxide electrocatalyst. The catalyst is prepared by taking ruthenium as a unique active component, fullerene (C60) as a carbon substrate and polydopamine (PDA) as an additive through argon heat treatment. The preparation method disclosed by the invention is simple and easy to implement, and through the design scheme that C60 with high electron affinity is used as a carrier, the electronic structure of a ruthenium active site is effectively adjusted, and excessive adsorption of a ruthenium-based catalyst to hydroxyl species in a hydrogen oxidation reaction (HOR) process is weakened, so that the ruthenium reaction active site is greatly reserved for hydrogen adsorption, and the hydrogen adsorption efficiency is improved. Therefore, the stability of ruthenium-based electro-catalysis in hydrogen oxidation reaction can be greatly improved.

The invention discloses a casing tubular reactor for preparing chlorine by oxidizing hydrogen chloride, which comprises a main body, and a lower seal head and an upper seal head which are respectively arranged at the bottom end and the top end of the main body, a casing reaction tube is arranged in the main body, and the casing reaction tube comprises a central tube and a jacket which is arranged on the outer wall of the central tube in a surrounding manner. A heating medium flows through the central pipe and the jacket, so that the heat exchange area is increased, and the heating medium is timely moved away from the reactor to take away heat generated by heat release of oxidation reaction, so that excessive concentration of bed reaction heat is avoided; and the obvious defect of traditional reaction equipment in the aspect of heat removal is overcome, the problems that the reaction efficiency is limited and the energy consumption is high are solved, and the reaction efficiency can be greatly improved. The invention also provides a system and a method for preparing chlorine by oxidizing hydrogen chloride, which realize recycling of reaction heat, reduction of energy consumption, recycling of tail gas discharged from an absorption tower after treatment, improvement of the utilization rate of raw materials, closed-loop operation of chlorine elements and reduction of the production cost.

The invention discloses a method for deeply removing arsenic from a nickel sulfate solution, which comprises the following steps: adjusting the pH value by using nickel hydroxide to form colloid to preliminarily remove arsenic, oxidizing by using sodium sulfate, and adding polyferric sulfate to form ferric hydroxide colloid to deeply adsorb and remove arsenic, and is simple in process, convenient to implement in the production process, capable of greatly reducing the cost and reducing the environmental pollution, and suitable for industrial production. The method comprises the following steps: adjusting the pH value of a low-pH leaching solution / anolyte / crude nickel sulfate dissolving solution to 4.0 or more by using nickel hydroxide, carrying out filter pressing to remove slag, adding arsenic ions in a sodium persulfate oxidation solution, reacting for 30 minutes, adding polyferric sulfate, reacting for 30 minutes, and carrying out filter pressing to obtain a nickel sulfate solution which is almost free of arsenic, and the method is efficient, safe and environment-friendly.

Methods and apparatuses for converting carbon dioxide to useful compounds are disclosed. The method involves reducing bicarbonate solution in an electrolyzer. Bicarbonate solution is supplied to the cathode. The direct reduction of bicarbonate at the cathode may be coupled with an oxidation reaction at the anode. The oxidation reaction may provide a source of protons (H+) to cathode for the reduction of bicarbonate. The oxidation reaction may be a hydrogen oxidation reaction (HOR). Hydrogen gas (H2) may be supplied to the anode. In some embodiments, a source of gas may be supplied to the bicarbonate solution to form a pressurized solution before supplying the solution to the cathode.

The invention provides a method for extracting tantalum and niobium from tungsten tailings, and belongs to the technical field of rare metal recovery, and the method comprises the following steps: adding a reducing agent, a fluxing agent, a covering agent and a slag former into the tungsten tailings, and heating and smelting under the protection of inert gas to obtain an alloy ingot; the alloy ingot is crushed and then leached through hydrochloric acid, and acid leaching residues containing tantalum, niobium and tungsten are obtained; the acid leaching residues are subjected to alkaline leaching, and alkaline leaching residues containing tantalum and niobium are obtained; the alkaline leaching residues are leached through hydrofluoric acid and sulfuric acid, and decomposition liquid is obtained; and extracting and separating the decomposition liquid to obtain tantalum hydroxide and niobium hydroxide, and respectively calcining the tantalum hydroxide and niobium hydroxide to obtain tantalum oxide and niobium oxide. The method is simple in technological process, convenient to operate, low in cost and suitable for industrial production, tantalum and niobium can be efficiently extracted from tungsten tailings, and good economic benefits and environmental benefits are achieved.

Provided here are methods for producing a shaped metal-supported catalyst. One such method includes the steps of mixing a support hydroxide with an aqueous mixture of an active metal compound to form a malleable mixture of an active metal incorporated support hydroxide, passing the malleable mixture through a molding device to produce a shaped metal-supported wet catalyst; and drying and calcining the shaped metal-supported wet catalyst. The support hydroxide contains one or more of aluminium hydroxide, silica hydroxide, zirconia hydroxide, cerium hydroxide, titanium hydroxide, lanthanum hydroxide, gallium hydroxide, or niobium hydroxide. The active metal compound can be one or more of vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, technetium, and rhenium.

The invention provides a preparation method of a cuprous oxide / cobaltosic oxide heterojunction composite material. The preparation method comprises the following steps: S1) growing cobaltous hydroxide on the surface of a carrier in situ; s2) calcining the cobaltous hydroxide, so as to obtain cobaltosic oxide; and S3) carrying out electroreduction deposition on the cobaltosic oxide in a mixed solution containing a copper source and an electrolyte to obtain the cuprous oxide / cobaltosic oxide heterojunction composite material. In the reduction reaction of electro-catalysis of 5-hydroxymethylfurfural, the prepared composite material serves as a catalyst, cuprous oxide serves as a main catalytic site for catalyzing reduction of HMF into DHMF, the capacity of generating active hydrogen through water dissociation is promoted due to existence of a cobaltosic oxide substrate, and therefore the selectivity of the product DHMF is improved; meanwhile, the composite material prepared by the invention shows excellent electrochemical catalysis performance and good cycling stability, and has a great application prospect in an HMF electroreduction reaction.

The invention belongs to the technical field of hydrogen production by electrocatalytic decomposition of water, and provides an iron-doped nickel hydroxide composite iron-doped cerium oxide electrocatalyst and application thereof in electrolyzed water. The iron-doped nickel hydroxide composite iron-doped cerium oxide electrocatalyst comprises a nickel substrate, wherein a porous catalytic activity layer of three-dimensional flower-shaped spherical nanoparticles formed by stacking two-dimensional nanosheets is loaded on the surface of the nickel substrate. The catalytic active layer comprises an iron-doped hexagonal stacked nickel hydroxide structure, the catalytic active layer comprises an iron-doped cubic stacked cerium oxide structure, and no iron with a crystalline structure exists in the catalytic active layer. The iron-doped nickel hydroxide composite iron-doped cerium oxide electrocatalyst disclosed by the invention shows excellent oxygen evolution performance in an oxygen evolution reaction of electrocatalytic water decomposition.

The invention discloses a Ru / Ni-3DONMC catalyst as well as a preparation method and application thereof, and relates to the technical field of new energy materials and electrochemical catalysis. According to the invention, self-designed ordered SiO2 microspheres are self-assembled as a template, a nitrogen-doped carbon carrier with a three-dimensional ordered hierarchical pore structure is constructed, and a composite catalytic system with a multi-stage active center is successfully prepared by combining a bimetallic precursor adsorption impregnation and thermal reduction process. The catalyst disclosed by the invention shows excellent bifunctional catalytic performance in an alkaline medium; only 16 mV overpotential is needed in a hydrogen evolution reaction under the current density of 10 mA cm <-2 >, and the Tafel slope is as low as 40.54 mV / dec; and in a hydroxide reaction, the material has high limiting current density of 2.55 mA cm <-2 > and excellent mass activity. And it is powerfully proved that the intrinsic catalytic activity and long-term operation stability of the hydrogen-electricity reaction can be effectively improved through a monatomic-nanocluster cooperative regulation strategy.

The invention relates to the technical field of electro-catalytic material synthesis, and particularly discloses a tower-shaped nickel hydroxide catalytic material and a preparation method thereof. The preparation method of the tower-shaped nickel hydroxide catalytic material comprises the following steps: (1) surface treatment of a nickel substrate: performing ultrasonic cleaning treatment on the nickel substrate, and performing vacuum drying to obtain the cleaned nickel substrate; and (2) synthesis of tower-shaped nickel hydroxide: dissolving phosphate to obtain a phosphate solution, adding hydrogen peroxide, stirring, adding the cleaned nickel substrate, and carrying out hydrothermal reaction to obtain a semi-finished product of tower-shaped nickel hydroxide. And (3) cleaning and drying the tower-shaped nickel hydroxide: cleaning the semi-finished product tower-shaped nickel hydroxide, and carrying out vacuum drying to obtain the tower-shaped nickel hydroxide catalytic material. The method is simple in process, relatively low in cost and easy for large-scale synthesis, and has a relatively good large-scale commercial application prospect; and the specific morphology effectively exposes active crystal faces and active sites, and as an excellent catalyst, the catalyst can improve the hydrogen production rate and the organic matter oxidation rate.

Methods and apparatuses for converting carbon dioxide to useful compounds are disclosed. The method involves reducing bicarbonate solution in an electrolyzer. Bicarbonate solution is supplied to the cathode. The direct reduction of bicarbonate at the cathode may be coupled with an oxidation reaction at the anode. The oxidation reaction may provide a source of protons (H+) to cathode for the reduction of bicarbonate. The oxidation reaction may be a hydrogen oxidation reaction (HOR). Hydrogen gas (H2) may be supplied to the anode. In some embodiments, a source of gas may be supplied to the bicarbonate solution to form a pressurized solution before supplying the solution to the cathode.

The invention discloses a copper-cobalt alloy / lanthanum hydroxide heterojunction catalyst and a preparation method and application thereof.The preparation method includes the steps that lanthanum-based perovskite oxide LaCu (1-x) CoxO3 is prepared through a sol-gel method, and x is equal to 0.1-0.5; laCu1-xCoxO3 is placed in hydrogen and argon mixed gas for reduction treatment, and the copper-cobalt alloy / lanthanum hydroxide heterojunction catalyst is obtained and used for preparing ammonia through electro-catalysis nitrate radical reduction. According to the preparation method, an in-situ dissolution strategy is adopted, a copper-cobalt alloy / lanthanum hydroxide strong interface coupled heterostructure is constructed, CuCo alloy nanoparticles provide high conductivity and rich active sites and form a heterostructure with La (OH) 3, the d-band center of the active sites is optimized through interaction of strong electrons, NO3 <-> adsorption and reaction intermediate stability are promoted, and the stability of the reaction intermediate is improved. The excellent electro-catalytic performance is realized.

The invention provides a method for recovering manganese from laterite-nickel ore. The method comprises the following steps: sequentially carrying out precipitation reaction and liquid-solid separation on substances comprising an alkaline precipitator, an oxidant and a nickel-cobalt-manganese-containing heavy metal solution to obtain a nickel-cobalt-manganese hydroxide product and a magnesium-containing solution. According to the principle, an oxidizing agent is added in the precipitation process, the redox environment in the nickel-cobalt-manganese containing heavy metal solution is changed, and manganese can be precipitated together with nickel and cobalt under the alkaline condition. Specifically, after a proper oxidant is added into the solution, divalent manganese can be oxidized into a high valence state, so that the divalent manganese can form stable and insoluble precipitates more easily under an alkaline condition, and the stable and insoluble precipitates and nickel and cobalt hydroxides are separated out together, thereby realizing high-efficiency recovery of manganese.

This invention relates to a hydrogen-form ZSM-48 molecular sieve, its synthesis method, and its applications. The hydrogen-form ZSM-48 molecular sieve has an average mesopore size of 6 nm to 30 nm, a B / L acid ratio of 0.7 to 3.4, and a specific surface area of ​​100 m². 2 / g~500m 2 / g. The synthesis method of the hydrogen-form ZSM-48 molecular sieve includes the following steps: (1) Under contact conditions, silicon source, aluminum source, template agent and water are mixed evenly to obtain a gel; (2) The gel obtained in step (1) is subjected to hydrothermal crystallization treatment, and then washed, dried and calcined to obtain hydrogen-form ZSM-48 molecular sieve. The template agent in step (1) includes hexamethylammonium hydroxide and urea; preferably, the template agent also includes urease. The synthesis method controls the molecular sieve pore size and B / L acid ratio by introducing urease and using a two-stage hydrothermal treatment method, thereby realizing the control of molecular sieve properties according to the target reaction characteristics, which is beneficial to improving the yield of low-branched isoalkanes and improving the quality of lubricating oil base oil.

Disclosed in the present invention is an application of sodium thiosulfate as an auxiliary agent for nickel-cobalt precipitation. The application comprises the following steps: (1) adding sodium thiosulfate to a solution after iron and aluminum removal, and stirring at 50-65°C to obtain a nickel-cobalt precipitation stock solution; (2) adding an alkali to the nickel-cobalt precipitation stock solution, adjusting the pH of a system to 7.0-7.4, and maintaining the pH to allow for sufficient precipitation of nickel and cobalt to obtain precipitate; and (3) washing the precipitate to obtain mixed hydroxide precipitate (MHP). In the present invention, sodium thiosulfate is used as the auxiliary agent for nickel-cobalt precipitation, and the precipitation rate of nickel and cobalt from the solution after iron and aluminum removal is promoted by means of the addition of the auxiliary agent, reducing the content of manganese in MHP product. The present invention has good economic value and is easy for industrial application.

The invention discloses a preparation method of a Ni / Ni (OH) 2 heterojunction nano electrocatalyst and application of the Ni / Ni (OH) 2 heterojunction nano electrocatalyst in hydrogen production. The method comprises the following steps: preparing a eutectic solvent; then adding nickel salt, heating and stirring to fully dissolve the nickel salt without crystal precipitation; adding an imidazole additive, and uniformly stirring to obtain an electrolyte; the electrolyte is added into an electrolytic bath for electro-deposition, and a uniform and compact Ni / Ni (OH) 2 heterojunction layer is gradually deposited on the surface of a cathode; and cleaning, drying and activating the cathode electrode to obtain the catalyst. According to the preparation method, imidazole is introduced into a choline chloride-ethylene glycol eutectic solvent system, and an electro-deposition technology is adopted, so that synchronous deposition and interface bonding of nickel and nickel hydroxide are realized at one time, the Ni / Ni (OH) 2 heterojunction is obtained, and a tedious multi-step process in a traditional method is avoided; in addition, the high efficiency and long-term stability of the catalyst for catalyzing the hydrogen evolution reaction are improved, and good repeatability and industrialization potential are achieved.

The application discloses a preparation method of a nickel-doped and high-hydrated cobalt-chromium-iron ore monocrystal under high temperature and high pressure, and the method comprises the following steps: preparing a cylindrical cobalt-chromium-iron ore sample by taking solid basic cobalt carbonate powder, solid chromium (III) acetate hydroxide crystal powder, solid nickel stearate, solid oxalic acid powder, solid chromium hydroxide powder, solid nickel hydroxide powder and liquid dilute nitric acid as starting raw materials; preparing water source sheets by taking chromium hydroxide powder and nickel hydroxide powder in a weight ratio of 4:1; placing two water source sheets at two ends of the cylindrical cobalt-chromium-iron ore sample respectively and then putting them into a double-capsule structure sample bin; and obtaining a cobalt-chromium-iron ore monocrystal after high-temperature and high-pressure reaction, so that the blank of the preparation technology of the nickel-doped and high-hydrated cobalt-chromium-iron ore large-grain monocrystal under the current high-temperature and high-pressure condition is solved, and the experimental sample of the nickel-doped and high-hydrated cobalt-chromium-iron ore large-grain monocrystal is obtained.

The invention provides a chemical composition for removing etching residues, which comprises organic ammonium, a corrosion inhibitor, an organic solvent, an inhibitor, hydroxylamine and deionized water, the organic ammonium is selected from one or more of choline hydroxide, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutyl ammonium hydroxide, tributyl methylammonium hydroxide, benzyl trimethyl ammonium hydroxide, ethyl trimethyl ammonium hydroxide, diethyl dimethyl ammonium hydroxide and tris (2-ethoxyl) methylammonium hydroxide, and the organic ammonium is selected from one or more of choline hydroxide, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutyl ammonium hydroxide, tributyl methylammonium hydroxide, benzyl trimethyl ammonium hydroxide, ethyl trimethyl ammonium hydroxide, diethyl dimethyl ammonium hydroxide and tris (2-ethoxyl) methylammonium hydroxide; the inhibitor is selected from one or more of fructose, galactose, lactose, maltose, glucose, ascorbic acid, hydroxylamine sulfate and ethanol hydrazine. Compared with the prior art, the chemical composition for removing the etching residues can effectively remove the residues after plasma etching, meanwhile, etching of AlCu, TiN / Ti and silicon oxide is avoided, an operation window is large, and the chemical composition has good application prospects in the semiconductor etching process.

This invention discloses a platinum-based catalyst for the hydrogenation reaction, its preparation method, and an electrode. The catalyst uses orthorhombic niobium pentoxide (T-Nb₂O₅) as a support to support the active component platinum. The support is resistant to strong acids and electrochemical corrosion at potentials above 1.0 V (vs RHE). The catalyst exhibits a hydrogenation reaction current density of not less than 200 mA·cm⁻¹ at 0.45 V (vs RHE). ‑2 In preparation, ammonium niobate oxalate hydrate was used as the niobium source, and the mixture was gelled via a sol-gel method. The gel was then heat-treated at 600-700℃ to obtain an orthorhombic niobium pentoxide support. The pH was adjusted to less than 3, and platinum was reduced with sodium borohydride to prepare the catalyst. This catalyst was then used to fabricate a hydrogen depolarization anolyte gas diffusion electrode with a platinum loading of 0.5-1.0 mg·cm³. ‑2 It can operate continuously and stably for no less than 120 hours with a cell voltage in the range of 1.25-1.45V. The catalyst of this invention has high activity and excellent stability, and can be used as a hydrogen depolarization anode in hydrometallurgy, significantly reducing electrolysis energy consumption and making it suitable for industrial applications.

The invention belongs to the technical field of tungsten alloys, and particularly discloses a tungsten alloy catalyst and a preparation method thereof.The preparation method comprises the steps that tungsten powder, iron powder, cobalt powder, manganese powder, yttrium oxide powder and titanium oxide powder serve as raw materials, graphene serves as an activating agent, the raw materials are blended, then special pore forming of ammonium bicarbonate and rubidium hydroxide and corrosion of nitric acid are conducted, and the tungsten alloy catalyst is obtained. The tungsten alloy catalyst with excellent catalytic activity is obtained by coating a tin compound (changed into tin oxide through heat treatment), finally carrying out three times of heat treatment, eliminating internal stress in the alloy through the first time of heat treatment, inducing generation of metastable intermetallic compounds through the second time of heat treatment and finally carrying out high-temperature sintering, and the tungsten alloy catalyst can be used for catalytic hydrogen production.