35results about How to "Improve reaction stability" patented technology

The invention provides a novel nano material as well as an immobilized enzyme and application thereof, and relates to the fields of biotechnology and application, material synthesis and application, water environment treatment and environmental protection. The particle size of the nano material is 2-30 microns, and the aperture of the surface is 2-30 nm; the solid nanomaterial is prepared by the following method: adding an alkali solution into a metal salt solution, fully mixing, then adding a ligand aqueous solution, fully reacting, and then separating to obtain the solid nanomaterial. When the material is used for immobilizing enzyme, the particle size of the obtained immobilized enzyme is 2-20 microns, and the aperture of the surface is 1-15 nm; the preparation method comprises the following steps: mixing an enzyme with a ligand aqueous solution, then adding the mixture into a metal salt mixed solution, and separating a solid product. The nano material has excellent biocompatibility and mild synthesis conditions, can protect the reaction activity of the enzyme under harsh conditions such as high temperature, acid and alkali, and improves the recycling capability and storage capability of the enzyme.

The invention relates to the field of sodium citrate preparation, in particular to a double-cooling type decolorizing and refining device and application thereof in sodium citrate preparation.The double-cooling type decolorizing and refining device comprises a reaction tank, a stirrer is arranged in the reaction tank, the double-cooling type decolorizing and refining device further comprises an outer cooling jacket and an outer cooling coil, and a cooling area is formed between the outer cooling jacket and the reaction tank; the outer cooling jacket is provided with an air inlet and an air outlet, and the outer cooling coil is provided with a water inlet and a water outlet. The rotating speed of the stirrer is detected through the rotating speed sensor, the flow adjusting assembly is adjusted according to a rotating speed signal, the cold air flow and the cooling water flow are gradually increased, the opening degree of the air inlet and the opening degree of the water inlet are gradually increased along with increasing of the rotating speed of the stirrer, continuous improvement of the cooling effect is ensured, and the particle size of formed crystals is effectively controlled; the increase of the number of crystal nucleuses and non-uniform crystallization caused by rapid cooling are avoided, so that the purity and the yield of the sodium citrate are improved.

The utility model discloses a kind of N, N-diisopropyl ethylamine neutralization distillation device, it is related to neutralization distillation technical field, the N, N-diisopropyl ethylamine neutralization distillation device, including neutralization reaction kettle, stirring mechanism and lye distribution mechanism are equipped in neutralization reaction kettle, lye distribution mechanism is installed in the upper portion of neutralization reaction kettle, it is arranged horizontally annularly, the lower end of lye distribution mechanism is fixedly connected with the upper end of stirring mechanism, and lye distribution mechanism is rotated simultaneously when driving stirring mechanism rotation, it is even sprayed into reaction liquid phase area in circumferential direction multiple points to alkali liquor, the efficient dispersion and mixing of alkali liquor are realized.The utility model is rotated by the synergistic effect of multiple point injection lye distribution mechanism and micro rectifier structure, realize the spatial uniform distribution and rapid mixing of alkali liquor in reaction system, effectively avoid local over-alkali, improve the uniformity, stability and product yield of neutralization reaction.

This invention discloses a graphene oxide / carbon nanotube-based coal combustion catalyst, its preparation method, and its applications, belonging to the field of catalytic combustion technology for efficient coal utilization. First, graphene oxide is used as a carrier, and then carbon nanotubes and manganese oxide are grown on its surface in a one-step process using condensation and redox reactions, followed by co-firing with coal. The graphene oxide / carbon nanotube-based combustion catalyst prepared by this invention effectively improves combustion efficiency, reduces the ignition temperature of coal, and lowers the reaction activation energy, resulting in significant economic benefits and broad application prospects.

A continuous solid-liquid reaction device for gas treatment belongs to the technical field of flue gas desulfurization and manganese resource recovery equipment and comprises more than three reaction kettles which are connected in series through gas guide pipelines, each reaction kettle is provided with a gas inlet pipe joint, a feeding pipe joint, a gas outlet pipe joint and a discharging pipe joint, and a gas distribution device communicated with the gas inlet pipe joint is arranged in each reaction kettle. A stirring device is also arranged; the gas distribution device comprises more than two layers of gas distribution pipes which are communicated through a communication pipeline; a plurality of gas distribution holes are formed in the side walls of the gas distribution pipes; the stirring device comprises more than two layers of stirring paddles, and the stirring paddles are arranged above each layer of gas distribution pipe. The core design of'mixing gas with liquid without mixing 'is adopted, the gas distribution device is combined with stirring, so that gas is uniformly released in a small bubble form, the retention time is prolonged, and multi-stage full utilization of the gas is realized in cooperation with the gas series design. And multi-layer graded gas distribution is matched with layered stirring, so that gas-liquid-solid three-phase contact is sufficient, the reaction is stable, and deposition and short circuit are avoided.

The application relates to the field of polyurethane foaming materials, and discloses a low-VOC polyurethane foaming compound and a preparation method thereof; the low-VOC polyurethane foaming compound comprises A component and B component which are mutually packed, the A component comprises low-aldehyde polyether polyol, polyether carbonate polyol, functionalized polyurethane oligomeric polyol, reactive tertiary amine catalyst, foam stabilizer and water, and the B component comprises a low-free-monomer isocyanate component; the functionalized polyurethane oligomeric polyol is prepared by reacting polyether carbonate polyol, diisocyanate and a hydroxyl compound containing a 1,3-dicarbonyl structure and having two or more hydroxyl groups. The preparation method comprises the steps of functionalized polyurethane oligomeric polyol preparation, A component dispensing, B component dispensing and packing. By introducing the reactive oligomeric polyol with the 1,3-dicarbonyl structure into the foaming system, the volatile components brought by raw materials can be reduced, and the continuous control ability of aldehyde components in the foaming process and the post-maturation process can be improved.

The present disclosure relates to a kind of multi-level hole pure silicon molecular sieve and its preparation method and cyclohexanone oxime catalytic reaction method.The multi-level hole pure silicon molecular sieve has the following diffusion coefficient characteristics: with cyclohexane as probe molecule, the diffusion coefficient of the probe molecule in the multi-level hole pure silicon molecular sieve is 0.015-0.02 μm 2 / min, measured by zero-length column method.The present disclosure can effectively improve the molecular diffusion performance of molecular sieve, and when the molecular sieve is used for cyclohexanone oxime gas phase Beckmann rearrangement reaction, the selectivity of caprolactam and the service life of catalyst can be effectively improved.

According to the static expansion fracturing material for upward drilling and the using method, calcium oxide serves as a main material, magnesium oxide, titanium oxide and citric acid serve as auxiliary materials, the main material and the auxiliary materials are both dry materials, and the main material and the auxiliary materials are evenly stirred, mixed and ground to obtain the static expansion fracturing material. The mass ratios of the calcium oxide, the magnesium oxide, the titanium oxide and the citric acid are 85.5%, 5.5%, 7.5% and 1.5% respectively. The invention has the advantages of scientific principle, easily available ingredients, simple manufacturing process, low cost, good cracking effect, advanced injection or installation, slow expansion cracking after encountering water, and safe and reliable use process.

The invention relates to an integral supported palladium-based catalyst and a preparation method and application thereof, and relates to the technical field of catalysts, the catalyst is composed of a carrier foamed nickel (NF), a noble metal palladium (Pd) and another metal for catalyst surface modification, the typical modified metal is magnesium (Mg), and the typical modified metal is magnesium (Mg). According to the preparation process, metal magnesium grows on NF to form a firm Mg-NF matrix, then palladium is loaded on the matrix, and the integral supported palladium-based catalyst Pd / Mg-NF is prepared, the method is simple in preparation, mild in condition, controllable in process and high in repeatability, and the product has good reaction activity and stability and has good practical application prospects.

This application relates to the technical field of material conveying equipment, and provides a jetting device for pyrite, including a feeding tank. A distribution cone and multiple discharge ports are provided at the bottom of the feeding tank, and the discharge ports are evenly arranged around the distribution cone. A flow-turbulence device is provided between adjacent discharge ports. The flow-turbulence device includes a flow-turbulence component and a first gas supply pipe. The flow-turbulence component includes a flow-turbulence element, and the pulsed airflow injected from the first gas supply pipe causes the flow-turbulence element to reciprocate. By providing multiple discharge ports, this application can supply a large quantity and evenly of pyrite ore to the downstream reaction tank through multiple feeding pipes, enabling a continuous and stable reaction within the reaction tank. The flow-turbulence device between adjacent discharge ports effectively solves the problems of uneven fluidization, material accumulation, and bridging of the pyrite ore during its reciprocating motion.

The invention discloses a catalyst for preparing ethylene and propylene through butene cracking as well as a preparation method and application of the catalyst. The catalyst is a core-shell H-ZSM-5 (at) MCM-41 molecular sieve, and the thickness of the shell layer of the MCM-41 is 10-60 nm; the preparation method comprises the following steps: dispersing an H-ZSM-5 molecular sieve into a solvent to obtain a mixture I; adding an alkaline solution and an organic template agent into the mixture I to obtain a mixture II; slowly dropwise adding a silicon source into the mixture II, stirring and hydrolyzing to obtain a modified solid-liquid mixture; and aging and roasting the modified solid-liquid mixture to obtain the catalyst. The catalyst is applied to a reaction for preparing ethylene and propylene through catalytic cracking of butene, and can improve the catalytic efficiency and prolong the reaction life.

The invention provides a method for blowing a micro-fine particle grade titanium-rich material in a fluidizing chlorination furnace, which comprises the following steps: step S1, drying and screening the micro-fine particle grade titanium-rich material to obtain titanium-rich material fine powder; s2, conveying the titanium-rich material fine powder to a chlorine pipeline of a boiling chlorination furnace; s3, the titanium-rich material fine powder is fully mixed with chlorine while being conveyed in a chlorine pipeline; and S4, a mixture of the titanium-rich material fine powder and chlorine is blown into a boiling chlorination furnace reaction zone. According to the method for blowing the micro-fine particle-grade titanium-rich material by the fluidizing chlorination furnace, the problem of resource waste caused by the fact that the micro-fine particle-grade titanium-rich material cannot be directly used for production of the fluidizing chlorination furnace is solved, efficient utilization of the micro-fine particle-grade titanium-rich material is realized through the blowing technology, the production cost is reduced, the energy consumption is reduced, and the yield and the quality of titanium tetrachloride are improved.

The invention provides an organic amine absorbent regeneration catalyst for carbon capture and a preparation method thereof. The organic amine absorbent regeneration catalyst comprises a carbon layer carrier and metal elements and nitrogen elements doped on the surface of the carbon layer carrier, the carbon layer carrier has a highly graphitized structure, and the ID / IG ratio of the Raman spectrum is less than 2; the metal elements are in an atomic-scale dispersed state on the surface of the carbon layer carrier; the metal element and the nitrogen element are coordinated and jointly loaded on the surface of the carbon layer carrier. The metal active substance in the catalyst is in the carbon-nitrogen protective layer, active sites are dispersed, and the stable protective layer is arranged around the active sites, so that the catalyst has higher reaction activity and stability; the catalyst has a highly graphitized structure, so that the stability and durability of the catalyst can be improved; the catalyst has a hierarchical porous structure, has a high specific surface area, contributes to reactant diffusion, and improves the reaction activity of the catalyst; strong acid and strong alkali etching can be endured, and the durability of the catalyst is improved; in addition, the catalyst can greatly improve the CO2 desorption performance of the organic amine absorbent.

This invention belongs to the field of smart city information technology, specifically relating to an automated steady-state control method for industrial robots in the continuous production of recycled ABS plastics. It covers the entire continuous operation of recycled ABS from material conveying and reaction plasticization to finished product output. Employing core algorithms such as dynamic coordination of material conveying and reaction demand, steady-state control of multi-parameter coupling in the reaction process, and full-process quality data chain traceability, it overcomes the technical bottlenecks of traditional continuous recycled ABS production, including "disconnected conveying, process fluctuations, and lack of traceability." This achieves precise coordination of continuous material conveying, stable and controllable reaction processes, and traceable quality control of finished products, significantly improving the stability, production efficiency, and quality reliability of continuous recycled ABS production, and adapting to the automated production needs of large-scale continuous recycled ABS products.

The application discloses a method for preparing L-serine by enzyme catalysis, and in-situ preparation of low-cost and high-activity THF is achieved by using a biological method or a chemical method; THF and enzyme inactivation are avoided by precisely controlling the flow addition of formaldehyde; the reaction system is optimized to promote the in-vivo circulation regeneration of THF, so that higher conversion efficiency is achieved with less THF feeding amount, and the use amount and cost of the expensive coenzyme THF are significantly reduced. The method is based on the optimization of the existing enzyme process, does not need complex equipment modification, and is easy to realize industrialized scale production.

This application relates to the field of reaction vessel technology and discloses a reaction vessel for producing environmentally friendly weather-resistant automotive coating curing agents. The reaction vessel includes a vessel body, with a vent pipe and several feed pipes fixedly connected to the top of the vessel body, and a discharge pipe fixedly connected to the bottom of the vessel body. A drive shaft is rotatably mounted on the axis of the vessel body, and a flat key is fixedly mounted on the shaft body inside the vessel body. This invention uses an electric push rod to drive the moving seat and filter mechanism to rise and fall. During the rising and falling process, the filter plate filters undissolved powder agglomerates and scrapes off materials adhering to the inner wall of the vessel body. When the probe contacts the pressure sensor at the top of the vessel body, the pressure sensor can reflect the contact pressure value that changes with the mass of the filtered material on the filter plate. This can correct the total weight detection value of the weighing sensor, reduce interference with weighing accuracy, improve the accuracy of component addition control and reaction endpoint determination, and improve reaction efficiency and product quality stability.

The invention relates to the technical field of vehicle transmission, in particular to a high-strength and sensitive-response electronic differential lock for a front axle and a rear axle, which comprises a differential shell assembly, a differential gear mechanism and a differential lock thrust actuating mechanism, the rear end of a differential case seat of the differential case assembly is connected with the front end of a differential case cover through the differential case connecting bolt after being butted; the differential mechanism gear mechanism comprises a left half axle gear, an embedded cross axle, a planetary gear and a right locking half axle gear, and the left half axle gear, the planetary gear and the right locking half axle gear are bevel gears which are sequentially matched and meshed; a differential locking thrust executing mechanism capable of preventing the right locking half axle gear from rotating is arranged on the rear side of the right locking half axle gear. According to the differential lock, the thrust executing mechanism, the embedded cross shaft and the sliding rail disc are all arranged on the differential shell cover, so that the structural compactness of the differential lock is improved, the response speed and the locking stability of the differential lock are remarkably improved, and the complexity of installation and maintenance is reduced.

The application discloses the technical field of high polymer synthesis and functional material modification, and relates to a preparation method of low-molecular-weight polyacrylamide. The method comprises the following steps: firstly, preparing a double-metal doped multi-level pore carbon nanotube-covalent organic framework composite modification material, and the preparation process comprises the following steps: surface functionalization of multi-walled carbon nanotubes, growth of a covalent organic framework layer, doping of double-metal ions, and subsequent reduction and calcination treatment; then, adding deionized water, acrylamide and the modification material into a three-necked flask, stirring under nitrogen to dissolve the acrylamide, preparing an oxidation-reduction initiator solution, and dropping the initiator solution into the system under the protection of nitrogen, and polymerization reaction is carried out in a constant-temperature water bath at 19-21 DEG C. After the polymerization is completed, the product system is washed, filtered, and finally, low-molecular-weight polyacrylamide is obtained by using a vacuum freeze-drying method. The polyacrylamide prepared by the method has low and controllable molecular weight, and has good solubility and salt resistance.

The invention relates to a multi-grain-boundary cerium-based catalyst as well as a preparation method and application thereof. The multi-grain-boundary cerium-based catalyst comprises a multi-grain-boundary cerium dioxide carrier and an active component loaded on the carrier, the active component comprises any one or a combination of at least two of copper oxide, manganese oxide or cobalt oxide. According to the multi-grain-boundary cerium-based catalyst, multi-grain-boundary CeO2 is adopted as a carrier, and compared with a traditional single-crystal Ce-based catalyst, the multi-grain-boundary Ce-based catalyst has rich grain boundary defects, so that generation of an oxygen vacancy active structure is promoted, and higher photochemical reaction activity is achieved. The structural advantages are beneficial to adsorption and activation of reactants and generation of active oxygen species, so that the deep oxidation performance of the catalyst on VOCs is remarkably improved. Compared with the traditional thermocatalysis, the application of the photothermal catalysis technology reduces the energy consumption of external heating. The multi-grain-boundary cerium-based catalyst has excellent low-temperature degradation capability and reaction stability, so that the multi-grain-boundary cerium-based catalyst has a good application prospect in purification of VOCs (Volatile Organic Compounds) in industrial flue gas.

The present application relates to mixed reaction device, more particularly to fixed reactor technical field, and disclose a kind of viscous material mixing reaction device containing pitch and its process, including horizontal reactor and with one body kettle body, the kettle body is provided with driving portion, the driving portion is connected with positioning portion and swing portion, the positioning portion and swing portion are connected with reaction portion, the reaction portion is connected with material shaking portion, the horizontal reactor is provided with feeding port, the feeding port is equipped with feeding portion, the driving portion includes driving motor, the driving motor is installed on the shell of horizontal reactor, by the cooperation of helical blade and stirring rod, the rotation of stirring rod is realized in the process of revolution by viscous material flow, cooperate with the swing action of hinged ring one as axis, realize multidimensional strong disturbance mixing, different from traditional single stirring form, significantly improve material dispersion uniformity and reaction consistency, guarantee the overall stability of finished product.

This invention belongs to the field of catalytic ammonia oxidation technology, and specifically relates to a Ru / AMn2O4 catalyst for the gas-solid phase synthesis of methacrylonitrile, its preparation method, and its application. The catalyst preparation includes the preparation of an AMn2O4 spinel support, AMn2O4 spinel support pretreatment, and Ru / AMn2O4 catalyst preparation. The catalyst of this invention, prepared by the above method, possesses advantages such as high activity at low temperature, high stability, high conversion rate of methacrolein, high yield of methacrylonitrile, and low yield of the byproduct hydrogen cyanide. It is particularly suitable for use as a catalyst in the gas-solid phase ammonia oxidation of methacrolein to methacrylonitrile.

The invention discloses a nitrogen-carbon modified catalyst for preparing butadiene from ethanol as well as a preparation method and application thereof, and belongs to the technical field of preparation of butadiene from ethanol. Two active components M1 and M2 are loaded in the catalyst, M1 is one or more than two of Cu, Zn, Ag, Cr and Co, M2 is one or more than two of Zr, Hf, Ta, Y, Sn and Nb in an oxidation state, and the total loading amount of the active metal M1 and M2 in the catalyst is greater than or equal to 0.1 wt%; the loading amounts of the nitrogen element and the carbon element in the catalyst are both greater than or equal to 0.1 wt%, the carrier is a silicon-based carrier, and the catalyst is obtained by co-dipping a soluble salt containing active components M1 and M2 and a solution of a soluble nitrogen carbon source in the silicon-based carrier, drying and roasting in inert gas, the catalyst disclosed by the invention shows ultrahigh activity and butadiene selectivity in a reaction for preparing butadiene from ethanol by a one-step method, the ethanol conversion rate reaches 90% or more, the butadiene selectivity reaches 70% or more, and the catalyst can stably run for 200 hours or more and has a very good application prospect.

The utility model discloses a kind of multizone reactors of multistage temperature control belongs to reactor temperature control technical field.The reactor includes multizone reactor body, circulating gas compressor, reactor cooler and multistage control valve group.Multizone reactor body includes ascending section and descending section, gas enters gas circulation through the top of descending section;The inlet of circulating gas compressor is communicated with the top of descending section, and circulating gas compressor is used to compress circulating gas;The inlet of reactor cooler is communicated with the outlet of circulating gas compressor, and the outlet of reactor cooler is communicated with multizone reactor body, and the outer periphery of reactor cooler is provided with jacket pipe line, for passing into cooling medium to cool circulating gas;Multistage control valve group is arranged on jacket pipe line to control cooling medium flow in stages to cool circulating gas in stages.The multizone reactor of multistage temperature control provided by the utility model can control temperature in stages, significantly improve the precision of temperature control, avoid temperature sustained shock, reduce the risk of reactor caking.

The invention discloses a near-distance nickel oxide cluster and nickel monatomic synergistic two-electron oxygen reduction electrocatalyst growing on a carbon substrate and a preparation method thereof, the preparation method comprises the following steps: carrying out oxidation treatment on the carbon substrate to obtain the carbon substrate with the surface rich in oxygen functional groups; dispersing the carbon substrate in a solvent to form a carbon-containing solution, and introducing a nickel salt metal precursor into the carbon-containing solution; under the action of a reducing agent, enabling the nickel precursor to form a nickel oxide cluster and nickel monatomic coexisting structure on the surface of the carbon substrate; and separating and drying to obtain the electrocatalyst. The electrocatalyst comprises a carbon substrate as well as nickel oxide clusters and nickel monoatoms which are distributed on the surface of the carbon substrate. The electrocatalyst can be applied to electrocatalytic preparation of hydrogen peroxide in a two-electron oxygen reduction reaction.

This invention relates to the field of CO2 resource utilization and hydrogenation catalysis technology, and discloses a highly zinc-loaded mesoporous alumina-based CO2 hydrogenation catalyst, its solvent-free preparation method, and its applications. The preparation method includes: mixing and stirring a structure-directing agent composed of a polyhydroxy organic compound and an organic acid, an inorganic acid, and an aluminum source in a sealed container to form a clear system; then slowly adding a zinc source solution and a copper source solution to obtain a homogeneous precursor; and finally drying and calcining to obtain the catalyst. The highly zinc-loaded mesoporous alumina-based CO2 hydrogenation catalyst (Cu-Zn@Al2O3) prepared by this invention has a specific surface area of ​​100–400 m² / g. 2 / g, with a pore size distribution of 2–50nm, which facilitates mass transfer and diffusion of CO2, H2, and products; the preparation method is solvent-free and uses a one-pot synthesis with few steps, suitable for the hydrogenation reaction of CO2 and H2 under fixed-bed conditions, and can be used to prepare methanol, methane, carbon monoxide and / or C1–C4 low-carbon hydrocarbons and reduce the CO2 content in the feed gas. When methanol is the main product, the methanol selectivity can reach ≥90%.

This invention discloses a nitrogen-carbon modified ethanol-to-butadiene catalyst, its preparation method, and its application, belonging to the field of ethanol-to-butadiene technology. The catalyst of this invention is loaded with two active components, M1 and M2. M1 is one or more of Cu, Zn, Ag, Cr, and Co, and M2 is one or more of oxidized Zr, Hf, Ta, Y, Sn, and Nb. The total loading of the active metals M1 and M2 in the catalyst is ≥0.1 wt%. The loadings of nitrogen and carbon in the catalyst are both ≥0.1 wt%. The support is a silicon-based support. The catalyst is obtained by co-impregnating a solution containing soluble salts of active components M1 and M2 and a soluble nitrogen-carbon source in the silicon-based support, drying, and calcining in an inert gas atmosphere. The catalyst of this invention exhibits extremely high activity and butadiene selectivity in the one-step ethanol-to-butadiene reaction, with an ethanol conversion rate of over 90% and a butadiene selectivity of over 70%. It can operate stably for over 200 hours and has excellent application prospects.

The invention relates to a method for preparing a heteroatom molecular sieve, which comprises the following steps: mixing a silicon source, a heteroatom source, an organic template agent, graphene powder and water at a first temperature to obtain mixed slurry; carrying out hydrolysis treatment on the mixed slurry at a second temperature to obtain a hydrolysis solution; carrying out a hydrothermal reaction on the hydrolysis solution, carrying out solid-liquid separation, and roasting a recovered solid-phase product; wherein the graphene powder is prepared by a supercritical carbon dioxide stripping method. The heteroatom molecular sieve prepared by the invention has rich hierarchical pore structures, the reactivity center of the heteroatom molecular sieve is high in accessibility, the heteroatom molecular sieve has better catalytic reaction activity and activity stability, and has higher target product selectivity, and on the other hand, the heteroatom molecular sieve prepared by the invention has suitable ordered mesopores and / or macropores, and the selectivity of the heteroatom molecular sieve is improved. The phenol hydroxylation reaction is facilitated, the phenol conversion rate is high, the benzenediol selectivity is good, and the para-ortho ratio of the benzenediol is high.

The invention relates to the technical field of electro-catalysis, and discloses a water electrolysis hydrogen evolution method which comprises the following steps: under a water electrolysis condition, taking a water electrolysis hydrogen evolution catalytic electrode as a working electrode to carry out water electrolysis reaction; wherein the water electrolysis hydrogen evolution catalytic electrode comprises a conductive substrate and a catalytic material compounded on the surface of the conductive substrate, and the catalytic material comprises a carbon-coated platinum-based alloy nano material and conductive carbon black; wherein the carbon-coated platinum-based alloy nano material contains a platinum-metal M alloy particle inner core and a graphitized carbon layer coated on the surface of the platinum-metal M alloy particle inner core, and the metal M is selected from at least one of Ni, Co and Zn. The water electrolysis hydrogen evolution method provided by the invention has relatively low reaction overpotential and relatively high reaction activity and stability.

This utility model relates to the field of flue gas desulfurization technology in cement kilns, specifically to a self-use cement kiln hot raw material nitrifier, including a conveying pipe, a water-cooled conveying assembly, a weighing device, a nitrification unit, a weighing screw conveyor, a storage bucket elevator, and a kiln bucket elevator. The water-cooled conveying assembly is located below the conveying pipe. This assembly is used to crush and cool the hot raw material before conveying it to the weighing device for weighing. The weighing device is installed on one side of the water-cooled conveying assembly and is used to weigh the hot raw material. Based on the weight of the hot raw material, the water supply device of the nitrification unit is used for water supply and nitrification. The nitrification unit is installed below the weighing device and is used for nitrifying the hot raw material. The weighing screw conveyor is installed below the nitrification unit and is used to weigh and convey the nitrated material. The weighing screw conveyor is equipped with a storage bucket elevator and a kiln bucket elevator.

The invention discloses a cobalt-based catalyst and a preparation method and application thereof, the cobalt-based catalyst is obtained by at least taking a cobalt-based precursor and an organic nitrogen source as raw materials through in-situ carbonization treatment; wherein the raw materials of the cobalt-based precursor at least comprise a cobalt salt, a zinc salt and an imidazole organic ligand. The preparation method comprises the following steps: dissolving cobalt salt and zinc salt in water to obtain a metal salt aqueous solution; the preparation method comprises the following steps: dissolving an imidazole organic ligand in water to obtain an imidazole organic ligand aqueous solution; the preparation method comprises the following steps: mixing a metal salt aqueous solution and an imidazole organic ligand aqueous solution, heating, aging, collecting a solid product, washing and drying to obtain a catalyst precursor; and mixing the catalyst precursor with an organic nitrogen source, and carrying out in-situ carbonization treatment to obtain the catalyst. The cobalt-based catalyst shows excellent catalytic activity and selectivity in the methanol oxidative carbonylation reaction, has good reaction stability, can still keep high methanol conversion rate and DMC selectivity after being recycled for five times, and has good industrial application potential.