19results about "Transition element hydrides" patented technology

Tantalum powder, comprising pure tantalum powder or tantalum alloy powder, wherein the particle size distribution of the tantalum powder has the following characteristics: (1) Dv90 < 5 μm; and (2) Dv10 > 0.5 μm. The tantalum powder has a narrow particle size distribution and does not contain nanoscale ultrafine particles, and has high stability and a high utilization rate. The present invention further relates to a method for preparing tantalum powder.

The invention provides a doped yttrium hydride neutron moderation material and a preparation method and application thereof, and belongs to the technical field of radiation shielding materials. At least one of samarium, europium and gadolinium is doped in yttrium hydride in the form of hydride, and the mass ratio of metal yttrium to metal gadolinium to metal europium to metal samarium is controlled, so that the neutron moderation effect of the neutron moderation material can be improved. According to the invention, at least one of gadolinium hydride, europium hydride and samarium hydride is mixed with yttrium hydride under the protective atmosphere, so that the mass content of each element in the doped yttrium hydride neutron moderation material can be accurately controlled. According to the invention, the mixture is sintered and molded, and the sintering parameters of sintering and molding are controlled, so that the components of the mixture are sintered in a compact state, cracks generated by thermal expansion and cold contraction can be reduced, and the doped yttrium hydride keeps high density and has fewer cracks and defects.

The application discloses a method for driving metal hydride reversible hydrogen storage by light. The method comprises the following steps: (1) introducing non-active gas into a sealed transparent reactor containing metal hydride powder; (2) applying light to the reactor to remove hydrogen and obtain a dehydrogenation product; (3) hydrogenating the dehydrogenation product in a hydrogen atmosphere to obtain the metal hydride; wherein the metal hydride is selected from at least one of alkali metal hydride, alkaline earth metal hydride and rare earth metal hydride; and the valence of hydrogen in the metal hydride is -1. In the application, the metal hydride can be directly driven by light energy, has high reactivity, and can realize reversible dehydrogenation cycle at normal temperature by using specific hydride, so that the process is simple and suitable for large-scale production.

The invention discloses a hexagonal scandium hydrogen compound and a preparation method thereof, and the preparation method comprises the following steps: taking a borane ammine complex as a solid hydrogen source, tabletting the borane ammine complex and elemental scandium through a mold, and stacking according to'hydrogen source-scandium-hydrogen source '; loading the assembly into a CVD diamond single crystal tube with holes, and carrying out secondary wrapping with NaCl to form a sealed reaction unit; carrying out segmented pressurization / depressurization in a cubic press, electrifying and segmented heating under the condition of 800-1200 DEG C, and carrying out pressure maintaining and cooling to complete synthesis; according to the method, local high hydrogen partial pressure is established under the action of moderate high pressure and double-layer sealing, external introduction of high-pressure hydrogen is avoided, and the equipment complexity and the safety risk are reduced; the product prepared by the invention is hexagonal-phase ScH3, can stably exist at normal temperature and normal pressure, and is different from cubic-phase ScH3 which can only be synthesized under an extreme high-pressure condition and cannot be kept stable after pressure relief, XRD and structure refinement are consistent with the standard, and the process can be repeated and amplified.

The application discloses a kind of rare earth hydride nanoparticles solvothermal method preparation process, it is with rare earth metal salt, lithium hydride and graphene as raw material, it is added in high-pressure reactor containing organic solvent and mixed uniformly, it is heated to 100-120 DEG C under inert atmosphere condition stirring, incubation reaction 1.5-2.5 h, after reaction is finished, cooling to room temperature, filter collection black product, wash with organic solvent, finally product is vacuum dried at 65-75 DEG C 1-2 h, obtain the rare earth hydride nanoparticles.The application process is simple and efficient, the product obtained is small and uniformly distributed, high purity, when it is used for neodymium iron boron magnet grain boundary diffusion technology, it can be effectively attached in the grain boundary region of neodymium iron boron magnet, decompose and release active rare earth element at high temperature, so as to adjust the composition and structure of grain boundary, can significantly improve the thermal stability and coercive force of magnet, while reducing the use amount of heavy rare earth and production cost.

Metal-based hydrogen storage fibers capable of selectively absorbing and desorbing / releasing hydrogen gas, and hydrogen storage vessels comprising the fibers, wherein the fibers are preferably arranged in a fabric. The fabric is a porous structure with a large surface area, which is well suited for hydrogen storage and transport. A hydrogen storage system is provided with attractive properties. Hydrogen storage in metal hydride fibers provides a compact and safe method of hydrogen storage, wherein hydrogen molecules in the gas phase can be adsorbed on the surface of the fibers, thereby forming metal hydrides, or dissociated into individual hydrogen atoms, which can further diffuse into the bulk of the metal hydride fiber and occupy sites in the metal hydride fiber matrix.

This application provides a hydride ion conductor comprising a rare earth metal binary hydride, the chemical formula of which is REH x In this formula, RE represents a rare earth metal, and the range of x is 1 to 10. In this application, rare earth metal binary hydrides or mixtures mainly composed of rare earth metal binary hydrides are used for the first time as hydride ion conductors, expanding the scope of research on solid electrolyte systems. The hydride ion conductors developed by this method exhibit excellent electrical conductivity not only at room temperature but also at low temperatures, and the assembled all-solid-state hydride ion battery can operate at room temperature.

Disclosed herein are a method of preparing a solution of a metal hydride catalyst and a composition for a solution of a metal hydride catalyst, the solution comprising gt; and 50% of a liquid hydrosilane that is both a solvent component of the metal hydride catalyst and a reactant in a process for converting HFO-1243zf in the composition or product stream to HFO-1252zc.

Disclosed is a preparation method for a nano magnesium hydride-loaded composite material, comprising the following steps: adding a cationic surfactant into an aqueous dispersion of a two-dimensional transition metal carbide, such that two-dimensional transition metal carbide nanosheets wrinkle, avoiding re-stacking, and then washing and drying same; packing the dried product into a sealed container, vacuumizing same and then raising the temperature to a high temperature, maintaining the temperature for a period of time, then filling the sealed container with high-pressure hydrogen, and maintaining the temperature for a period of time; and finally, adding the product that is subjected to heat treatment and dibutyl magnesium into an organic solvent to obtain a mixture and carrying out ultrasonic dispersion on same, stirring and heating for 12-48 hours under conditions that the hydrogen pressure is 3-6 MPa and the temperature is 180-220°C, and carrying out centrifugal drying to then obtain a nano magnesium hydride-loaded composite material. The two-dimensional transition metal carbide nano magnesium hydride-loaded composite material prepared in the present invention has advantages such as high hydrogen storage density, rapid hydrogen absorption and desorption dynamic performance and excellent cycle stability.

The invention provides a preparation method for rapidly preparing low-oxygen-content titanium hydride powder, and relates to the technical field of metal chemical engineering, the method sequentially comprises the following steps: SP1 raw material preparation: crushing and screening titanium or titanium alloy cast ingots, residual materials or cuttings to obtain granular raw materials; sp2 vacuum rolling desorption drying is conducted, and treatment is conducted for 1-2 h at the temperature of 120-180 DEG C and the vacuum degree smaller than or equal to 10 Pa; sp3 is subjected to vacuum preheating activation to 300-450 DEG C and stays for 5-30 min; the method comprises the following steps: carrying out primary enhanced hydrogenation on Sp4, and under the conditions of 500-650 DEG C and 10-100 kPa, spraying or permeating hydrogen downwards through a distributed hydrogen supply structure, so that the hydrogen and settled particles are in parallel flow or counter flow contact to generate a hydrogenation product; sp5 dehydrogenation-deoxidation coupling is carried out, vacuum dehydrogenation is carried out at the temperature of 700-850 DEG C and the pressure of 0.1-50 Pa, and magnesium steam / calcium steam is introduced for steam deoxidation; carrying out secondary hydrogenation and phase determination on Sp6; and after cooling to be less than or equal to 150 DEG C, cyclone separation and closed filtration are performed, and a finished product is collected. According to the method, the hydrogenation end point can be judged, deoxidation is stable, continuous closed production is achieved, and low-oxygen powder is obtained.

Disclosed herein are a process to prepare and a composition for a solution of a metal-hydride catalyst that includes > 50% of a liquid hydrosilane that is both a solvent component for the metal-hydride catalyst and a reactant in a process to convert HFO-1243zf in a composition or product stream to HFO-1252zc.

This invention provides a method for preparing a modified magnesium-based hydrogen storage material, comprising the following steps: mixing a certain amount of magnesium-based hydrogen storage material precursor with a certain amount of dispersion at room temperature and stirring until homogeneous; adding a certain amount of acid etchant dropwise under continuous stirring; reacting for 1-3 hours; then separating the solid phase material and drying it under vacuum to obtain the modified magnesium-based hydrogen storage material. The modified magnesium-based hydrogen storage material of this invention is obtained through a simple acid etching process, which can effectively improve the catalytic activity of the material in the hydrogenation reaction of organic liquids, thereby solving the problem of low hydrogenation activity and high energy consumption caused by long reaction times of existing catalysts.

This invention provides a yttrium hydride material with a hydrogen permeation barrier coating and a method for preparing the hydrogen permeation barrier coating. The method includes the following steps: adding aluminum salt and chromium salt to a mixed solvent containing alcohol, reacting with stirring, and aging to prepare an alumina and chromium oxide composite sol-gel system; immersing a cleaned yttrium hydride substrate into the alumina and chromium oxide composite sol-gel system, and forming a composite sol-gel film on the surface of the yttrium hydride substrate using an dip-coating method; and calcining the yttrium hydride substrate containing the composite sol-gel film to transform the composite sol-gel film into a dense hydrogen permeation barrier coating. This invention prepares the raw materials constituting the coating into a sol system, and uses an dip-coating + calcination method to form a hydrogen permeation barrier coating on the surface of the yttrium hydride substrate. The yttrium hydride material with the hydrogen permeation barrier coating can be used in small nuclear reactors as a neutron moderator, which can effectively improve the service life of the yttrium hydride material.

The application discloses a method for nitrogen fixation of rare earth metal hydride, and belongs to the technical field of nitrogen fixation of metal hydride. The rare earth metal hydride is contacted with nitrogen gas, and then reacts to obtain a rare earth metal nitrogen-hydrogen compound and a rare earth metal nitride after adding nitrogen. The application provides new insights and ideas for the design of a rare earth-based catalyst and a nitrogen carrier for catalytic ammonia synthesis and chemical chain ammonia synthesis, and has a wide application prospect.

The titanium hydride powder according to the present invention contains TiH2, is used in an active metal brazing filler metal, and when analyzed by image analysis, has an average particle diameter D50 in the range of 0.1-10.0 [mu] m, and has a number ratio of 15% or less of particles having a particle diameter of 15 [mu] m or more.

This application utilizes intermetallic compounds rich in Al or Zn, doped with noble metal elements in a solid solution, as precursors. At atmospheric pressure and near the boiling point of an alkaline solution, the intermetallic compounds doped with noble metal elements are reacted with the alkaline solution, enabling the efficient preparation of nano metal oxides with noble metal nanoparticle doping and varying degrees of crystallinity under atmospheric conditions. Additionally, based on the nano metal oxides doped with noble metal nanoparticles, this application provides a method for preparing noble metal nanoparticles. The preparation method described in this application is characterized by its simplicity, ease of operation, high efficiency, and low cost. The resulting products have broad applications in fields such as composite materials, catalytic materials, ceramic materials, refractory materials, advanced electronic materials, battery materials, chromogenic materials, microwave-absorbing materials, wastewater degradation materials, antibacterial materials, coatings, pigments, thermal spray materials, and sensors.

The present disclosure relates to a method of preparing a nano-porous powder material. The method includes: firstly removing A in the alloy AxTy by using an ultrasonically-assisted de-alloying method to prepare a nano-porous T coarse powder, and then, allowing the nano-porous T coarse powder to perform M-ization reaction with a gas reactant containing M to obtain a nano-porous T-M coarse powder, and finally, further crushing the nano-porous T-M coarse powder using a jet mill to obtain a nano-porous T-M fine powder. The method can achieve low-cost mass production of the nano-porous T-M fine powder, bringing broad application prospects.

The invention discloses a solvothermal preparation process of rare earth hydride nanoparticles, which comprises the following steps: by taking rare earth metal salt, lithium hydride and graphene as raw materials, adding the raw materials into a high-pressure reaction kettle containing an organic solvent, uniformly mixing, stirring and heating to 100-120 DEG C under an inert atmosphere condition, carrying out heat preservation reaction for 1.5-2.5 hours, cooling to room temperature after the reaction is finished, filtering, washing and drying to obtain the rare earth hydride nanoparticles. And filtering and collecting a black product, cleaning with an organic solvent, and finally carrying out vacuum drying on the product at 65-75 DEG C for 1-2 hours to obtain the rare earth hydride nanoparticles. The process is simple and efficient, and the obtained product is small in particle size, uniform in distribution and high in purity, can be effectively attached to a grain boundary area of the neodymium-iron-boron magnet when being applied to a grain boundary diffusion technology of the neodymium-iron-boron magnet, and is decomposed and releases active rare earth elements at high temperature, so that components and structures of grain boundaries are adjusted, and the performance of the neodymium-iron-boron magnet is improved. The thermal stability and coercive force of the magnet can be remarkably improved, and meanwhile the use amount and production cost of heavy rare earth are reduced.