12results about How to "Prevent sintering" patented technology

This invention relates to the field of marine propulsion technology, specifically to an auxiliary propulsion structure for electric ships. The structure includes a ship hull, a propeller mounted on the bottom of the hull, and rotating rods fixedly connected to both sides of the hull. An auxiliary propeller is mounted on each rotating rod. Through an idling cooling mechanism, when the water inlet is above the water surface, causing the drive rod to drive the auxiliary propeller to idle, the idling cooling mechanism opens an emergency water path. This allows pre-stored cooling water from the tank to be precisely delivered via drip pipes to the junction of the drive rod and the bearing. This directional dripping forms a water film at the friction interface, providing immediate lubrication and drag reduction, as well as rapid heat absorption and cooling, preventing high-temperature wear, deformation, or sintering of components. Compared to traditional unprotected designs, this mechanism is fast-responding and highly targeted, minimizing damage to core components during idling and ensuring reliable operation of the auxiliary propeller in complex waters.

This invention discloses a two-step hydrothermal method for preparing nickel-iron bimetallic MOF derivatives and its application. By controlling the precursor structure through a two-step hydrothermal strategy, the nickel-iron bimetallic MOF derivative catalyst forms a foam-like hierarchical porous carbon framework. The metal nanoparticles are uniformly dispersed, small in size, and encapsulated by carbon layers, significantly improving the specific surface area and accessibility of active sites. It exhibits excellent hydrogen yield and anti-carbon deposition performance in plastic pyrolysis tar reforming. The synergistic effect of nickel and iron electrons effectively inhibits metal sintering and carbon deposition, and has good catalytic stability. This invention solves the problem in existing nickel-iron bimetallic MOF derivatives where phase separation easily occurs in one-step synthesis due to the difference in nucleation and growth rates between nickel and iron ions and organic ligands, leading to uneven metal distribution, increased particle size, underdeveloped pore structure, and low accessibility of active sites, thus affecting catalytic reforming activity and anti-carbon deposition ability.

This invention discloses a method for preparing a metal phosphide catalyst. The method involves uniformly mixing a carbon-containing precursor with a phosphorus-containing precursor solution and then drying the mixture to obtain a solid product. The solid product is then pyrolyzed under an inert atmosphere. The pyrolyzed solid product is washed and dried to obtain a phosphorus-doped carbon material. A metal salt solution is then uniformly mixed with the obtained phosphorus-doped carbon material, dried, and reduced under a hydrogen-containing gas atmosphere to obtain the metal phosphide catalyst. Thus, this invention prepares phosphorus-doped porous carbon through the pyrolysis of a carbon precursor and a phosphorus-containing precursor. This utilizes the binding effect of phosphorus functional groups with metal ions to inhibit the migration and aggregation of metal particles under high-temperature conditions, effectively preventing metal particle sintering and improving the yield of the target catalytic product.

The application belongs to the technical field of ship exhaust purification, and particularly relates to a catalyst for decomposing N2O in the exhaust of a ship ammonia internal combustion engine and a preparation method thereof. 3+ By replacing Co ions in the Co3O4 spinel lattice into the lattice, the doping behavior can effectively reduce the number of hydroxyl groups on the surface of the catalyst, significantly weaken the adsorption and combination ability of water molecules, and thus improve the stability of the catalyst in a high-humidity exhaust environment. As an additive, CeO2 uses its oxygen storage capacity to promote the migration and desorption of oxygen species in the reaction, preventing the deactivation of active sites due to oxygen poisoning. The molecular sieve carrier not only provides a highly dispersed surface for the active component to prevent sintering, but also optimizes the adsorption and activation path of N2O and alleviates the poisoning effect of nitrogen-containing intermediate species or impurities in the exhaust on the Co active center during the reaction.

The embodiment of the application provides a kind of propane ammoxidation preparation acrylonitrile, it is related to acrylonitrile generation technical field;The method comprises: propane, ammonia and oxygen are mixed, and mixed gas is obtained;The mixed gas occurs ammoxidation under the action of metal oxide composite catalyst, and acrylonitrile is obtained;The metal oxide composite catalyst includes Mo-V base metal oxide, and also includes alkali metal or alkaline earth metal.The method of the present application has relatively mild reaction conditions, the yield can basically reach more than 60%, the selectivity can reach more than 80%, improves the raw material utilization rate, reduces energy consumption and equipment investment, thereby effectively reducing the production cost of acrylonitrile.At the same time, the process of the present application can effectively control the side reaction in the reaction process, reduce the generation of by-products, and reduce the difficulty of subsequent separation and purification of reaction products.

The application belongs to the technical field of hydrogen production, and discloses a preparation method of a nickel-based catalyst based on expanded graphite dispersion and application of the catalyst in hydrogen production by ammonia cracking, which comprises the following steps: (1) uniformly dispersing expanded graphite in deionized water; (2) adding nickel chloride hexahydrate and cerium chloride heptahydrate to uniformly disperse on the surface of the expanded graphite; (3) adding sodium borohydride to the mixture to perform reduction, centrifugation and washing; (4) calcining the obtained solid by centrifugation, and oxidizing and crystallizing Ce(III) into CeO2 under a high-temperature environment; and (5) reducing to obtain a Ni / CeO2-expanded graphite catalyst under pure hydrogen condition. The three-dimensional precursor is formed by the reduction method of nickel chloride, cerium chloride and expanded graphite, Ni and CeO2 are dispersed and fixed on the expanded graphite, and through the confinement effect and electronic transfer synergistic effect of the expanded graphite, the catalyst exhibits excellent catalytic activity in the ammonia decomposition reaction.

This invention discloses an iron-based multimetallic catalytic material, its preparation method, and its application, belonging to the field of catalyst preparation technology. The preparation method includes: dissolving two or more water-soluble metal salts with different hydroxide solubility products in water to obtain a mixed solution A; dissolving potassium ferrate in cold water to obtain solution B; pouring solution B into mixed solution A under stirring to obtain mixed solution C; allowing the solution to settle at low temperature until the supernatant changes color from dark purple to light purple and reaches neutral pH, then filtering, washing, and drying to obtain a precursor; calcining the precursor in a mixed atmosphere of hydrogen and argon to obtain the iron-based multimetallic catalytic material. This material has a multi-layered enclosed microstructure, with metal oxides of high hydroxide solubility products located on the periphery and those of low solubility products located inside, achieving a gradient arrangement and synergistic effect of metal components. The process of this invention is simple and the conditions are mild. The obtained catalyst exhibits high catalytic activity, high selectivity, and excellent stability in the countercurrent water-gas reaction.

The application discloses a supported metal element synergistically modified copper-based catalyst and a preparation method and application thereof. The catalyst is composed of metal copper, metal gallium, an auxiliary element M and a carrier SiO2. In the preparation method, a Cu-Ga catalyst precursor is prepared through an ammonia evaporation method, and then the auxiliary element is added through ball milling. Mechanical shearing force and impact generated in the milling process can promote sufficient contact and uniform mixing of the auxiliary element and the precursor, so that the auxiliary element is more uniformly distributed and a strong interaction is formed. Under the condition that the hydrogen ester ratio is about 200, the application can still maintain a high methyl 3-hydroxypropionate conversion rate and 1,3-propanediol selectivity.

The application discloses a kind of Ce-La composite carrier load Cu-Ni bimetallic photo-thermal catalyst and its preparation method, for the defects of existing pure carrier oxygen vacancy concentration fixed, active metal is easy high-temperature agglomeration, catalytic activity and stability are insufficient, the Ce-La composite carrier is constructed by La doping modification in the application, and Cu-Ni bimetallic is formed 8Cu2Ni / aCebLa catalyst.La exists in the form of La-Ce-O solid solution, significantly improves the carrier oxygen vacancy concentration and activation capacity, while strengthening metal-carrier interaction, anchoring bimetallic particles to inhibit sintering, improve catalyst stability.

This invention relates to a C x N y This invention relates to a Pt@C fuel cell catalyst and its preparation method, belonging to the field of fuel cell catalyst technology. First, Pt@C is synthesized via a solvothermal reaction using ethylene glycol reduction. Then, it is mixed with a nitrogen-containing polymer material and cobalt chloride hexahydrate, and subjected to reduction in a reducing atmosphere, high-temperature treatment, carbon pyrolysis, and alloying to obtain porous nitrogen-containing carbon-coated Pt@C. x N y @PtCo / C catalyst. In the prepared catalyst, the porous coating layer significantly reduces the poisoning of catalyst particles by resin during fuel cell operation, improves cell activity, and extends cell life, exhibiting excellent activity and durability.