16 results about "Cobalt carbide" patented technology

The invention provides a catalyst with a hydrotalcite layered structure as well as a preparation method and application of the catalyst. The catalyst with the hydrotalcite layered structure contains cobalt carbide serving as an active center; the particle size of the cobalt carbide is 3-20 nm; the cobalt carbide is obtained by reducing and activating a cobalt-manganese composite oxide. The catalyst provided by the technical scheme of the invention is good in catalytic activity, and can simultaneously have high CO conversion per pass and high olefin selectivity.

The present disclosure relates generally to compositions and methods for producing Fischer-Tropsch catalysts. In particular, the present application relates to a process for preparing a catalyst material for use in a Fischer-Tropsch synthesis reactor comprising providing a first catalyst material comprising cobalt supported on a support; the first catalyst material is contacted with carbon monoxide at a first temperature and a first pressure, thereby forming a passivated catalyst material comprising cobalt carbide.

The present invention discloses a preparation method of a cobalt carbide composite catalyst for one-step preparation of light olefins, comprising the following steps: 1) Mix sugars and urea, heat and stir to obtain a molten liquid, then add cobalt salts, metal salts and electronic additives, and perform secondary heating and stirring; 2) Carry out isothermal heating on the obtained molten mixture, dehydrate and carbonize to obtain a black-brown solid with high porosity; 3) Under the protection of an inert gas, perform high-temperature heat treatment on the obtained black-brown solid with high porosity to obtain black precursor solid particles; 4) Carry out high-temperature calcination in an air atmosphere to obtain a composite metal oxide catalyst; 5) Carry out reduction and carbonization treatment to obtain the cobalt carbide composite catalyst. The cobalt carbide catalyst obtained by the present invention exhibits advantages such as high olefin selectivity, low CO2 selectivity and high stability in Fischer-Tropsch synthesis for olefin production; moreover, the involved preparation method is relatively simple, the raw material cost is low, and it is more suitable for popularization and application.

The invention discloses a surface hydrophilic catalyst for preparing a C2 + oxygen-containing compound from synthesis gas as well as preparation and application thereof, the catalyst takes a surface hydrophilic modified carbon-based material as a carrier, active components are metal cobalt and one or more than two of cobalt carbide and iron carbide, and two types of auxiliaries are loaded at the same time. The catalyst is prepared by adopting an equivalent-volume impregnation method, wherein an impregnation solution comprises soluble metal salt, metal salt of a first auxiliary agent and metal salt of a second auxiliary agent. Dipping the prepared mixed solution on a carrier, drying to obtain a catalyst precursor, roasting and carbonizing to obtain an activated catalyst, and applying the activated catalyst to a reaction for preparing a C2 + oxygen-containing compound from synthesis gas. By adopting the catalyst provided by the invention, the CO conversion rate and the selectivity of C2 + oxygen-containing compounds can be remarkably improved.

The application relates to the technical field of alloy wires, and discloses a low-expansion special alloy wire and a preparation process thereof. The special alloy wire is prepared from 4J36 alloy as raw material through the processes of hot rolling, cold drawing, low-temperature annealing, cold drawing, high-temperature annealing and surface treatment, and has high precision, high surface quality and excellent comprehensive mechanical properties; cobalt carbide nanoparticles are deposited on the surface of the hot-rolled wire rod to reduce the friction in the cold drawing process; cobalt elements diffuse into the alloy during high-temperature annealing to improve the strength, and a protective layer is formed to relieve the hydrogen embrittlement phenomenon in the pickling and phosphorizing process, which is beneficial to the generation of the phosphorizing film; a phosphorizing liquid is prepared, part of dilute phosphoric acid is polymerized into polyphosphoric acid through short-time high-temperature heating, and a composite additive obtained by compounding sodium dodecyl benzene sulfonate and polyethylene glycol is added to prepare a phosphorizing liquid which can form a complete and smooth phosphorizing layer on the surface of the alloy wire.

The invention provides a catalyst, a preparation method and application thereof, and a method for preparing primary amine by catalyzing nitrile compound hydrogenation, and particularly relates to the technical field of catalyst synthesis. The catalyst comprises a nickel / cobalt-based catalyst and nickel / cobalt carbide coated on the surface of the nickel / cobalt-based catalyst, wherein the nickel-based / cobalt-based catalyst is selected from any one of a supported nickel / cobalt-based catalyst, a Raney nickel / cobalt catalyst or a nickel / cobalt nanocrystal; a carbon source used in the nickel / cobalt carbide is any one or a combination of at least two of a gaseous carbon source, a liquid carbon source and a solid carbon source. The catalyst not only has high activity and good selectivity, but also can inhibit agglomeration and sintering of nickel / cobalt and prolong the service life of the catalyst, so that the efficiency and selectivity of hydrogenation reaction are improved, side reactions are reduced, the production cost is reduced, and powerful support is provided for industrial application of hydrogenation.

The present disclosure relates generally to compositions and methods for producing Fischer-Tropsch catalysts. In particular, the present application relates to a process for preparing a catalyst material for use in a Fischer-Tropsch synthesis reactor comprising providing a first catalyst material comprising cobalt supported on a support; contacting the first catalyst material with a first reducing agent at a first temperature and a first pressure to form a reduced catalyst material; the reduced catalyst material is then contacted with carbon monoxide, thereby forming a passivated catalyst material comprising cobalt carbide.

The invention relates to a method for preparing ethanol through hydrogenation of carbon dioxide under catalysis of cobalt tungsten carbide, and aims to solve the problems of low ethanol selectivity, harsh reaction conditions and the like of the existing non-noble metal catalyst system for preparing ethanol through hydrogenation of carbon dioxide. The method comprises the following steps: placing a cobalt tungsten carbide catalyst and a solvent in a reaction kettle, replacing air in the reaction kettle with carbon dioxide, continuously introducing carbon dioxide to 0.5-1.5 MPa, introducing hydrogen until the total pressure reaches 2.0-6.0 MPa, carrying out a stirring reaction under the conditions of the pressure range of 2.0-6.0 MPa and the temperature of 140-190 DEG C, cooling to room temperature, filtering, washing, and drying to obtain the ethanol. After the catalyst is separated, the reaction liquid is subjected to reduced pressure distillation to separate ethanol. The invention provides a method for preparing ethanol by adopting a cobalt tungsten carbide high-efficiency catalyst under mild reaction conditions, and the cobalt tungsten carbide high-efficiency catalyst is high in activity, ethanol selectivity and space-time yield.

This invention discloses a method for preparing a highly efficient Na-modified solid solution catalyst and its application in the synthesis of higher alcohols and co-production of higher olefins from syngas. The catalyst comprises a solid solution component and an auxiliary component, wherein the solid solution component is a cobalt-iron solid solution, and the auxiliary component is elemental sodium or an oxide. The reactive centers are the cobalt-iron solid solution, cobalt and cobalt carbide or cobalt oxide species, and elemental sodium or an oxide. This invention provides a novel method for preparing a Na-modified cobalt-iron solid solution catalyst and its application, which exhibits high activity and high C content. 6+ alcohols and C 5+ The reaction exhibits olefin selectivity and stability, with operating temperatures ranging from 200 to 350°C and reaction pressures between 0.5 MPa and 10 MPa. The catalyst structure is stable during the reaction, the preparation method is simple and easily reproducible, facilitating industrial application.

A method is provided for densifying a ceramic matrix composite (CMC) preform in which a porous CMC preform is subjected to slurry infiltration wherein metal carbide particulate material is introduced into the spaces between fiber tows of the CMC preform to form an infiltrated CMC preform. Thereafter, molten metal or molten metal alloy is introduced into the infiltrated CMC preform by melt infiltration to react the metal or molten metal alloy with the metal carbide particulate material and create a ceramic matrix within the CMC preform forming a ceramic matrix composite. The metal carbide particulate material is selected from zirconium carbide particles, hafnium carbide particles, tantalum carbide particles, niobium carbide particles, titanium carbide particles, tungsten carbide particles, cobalt carbide particles, vanadium carbide particles, chromium carbide particles, ytterbium carbide particles, yttrium carbide particles, tantalum hafnium carbide particles, and mixtures thereof.

A method is provided for densifying a ceramic matrix composite (CMC) preform in which a porous CMC preform is subjected to slurry infiltration wherein metal carbide particulate material is introduced into the spaces between fiber tows of the CMC preform to form an infiltrated CMC preform. Thereafter, molten metal or molten metal alloy is introduced into the infiltrated CMC preform by melt infiltration to react the metal or molten metal alloy with the metal carbide particulate material and create a ceramic matrix within the CMC preform forming a ceramic matrix composite. The metal carbide particulate material is selected from zirconium carbide particles, hafnium carbide particles, tantalum carbide particles, niobium carbide particles, titanium carbide particles, tungsten carbide particles, cobalt carbide particles, vanadium carbide particles, chromium carbide particles, ytterbium carbide particles, yttrium carbide particles, tantalum hafnium carbide particles, and mixtures thereof.

The invention discloses a manufacturing process of a mining composite cast-forged wear-resistant cutting pick, which is characterized in that a cutting pick base body is made of 42CrMo steel, a tungsten-cobalt hard alloy tool bit is assembled on the base body after forging, quenching and low-temperature tempering, the tool bit and the base body are welded by adopting a laser cladding technology, ultrasonic impact treatment is carried out after welding, and finally the cutting pick is subjected to finish machining and shot blasting cleaning, so that the mining composite cast-forged wear-resistant cutting pick is obtained. And thus, a finished cutting pick workpiece is obtained. By designing the laser cladding process, the defect problems of uneven welding, cracks, holes and the like can be avoided, the process improvement is further combined, the wear resistance of the cladding layer is improved by optimizing the performance of the hard alloy for the wear-resistant part, and the high-strength mining composite casting and forging wear-resistant cutting pick can be obtained.

The present disclosure relates to a catalyst for preparing mixed alcohols by CO hydrogenation, a preparation method and application, the catalyst is a core-shell structure, cobalt carbide is the core, and copper oxide doped cobalt oxide is the coating layer. The present disclosure can well realize the synergistic catalysis among copper, cobalt metal and cobalt carbide active sites by constructing the core-shell structure of copper oxide doped cobalt oxide coated cobalt carbide, so that the catalyst provided by the present disclosure has excellent total alcohol selectivity and C 2+ alcohol selectivity; the catalyst provided by the present disclosure can make the total alcohol selectivity of CO hydrogenation for preparing mixed alcohols reach more than 47%, and the optimal can reach more than 55%, C 2+ alcohol selectivity is more than 69%, and the optimal can reach more than 74%, and has excellent catalytic effect.

The invention discloses a cobalt-based catalyst and a preparation method and application thereof. Comprising a cobalt element and an alkali metal element; the cobalt element exists in the form of a simple substance, cobalt oxide or cobalt carbide; the alkali metal element is selected from at least one of Li, Na, K, Rb and Cs; the alkali metal element exists in the form of a simple substance; in the cobalt-based catalyst, the total mass of the metal elements is 100 wt%, the content of the cobalt element is 50-99.5 wt%, and the balance is alkali metal elements. The catalyst has high activity and oxygen-containing compound selectivity in Fischer-Tropsch synthesis. The phenomenon of low selectivity of the oxygen-containing compound in Fischer-Tropsch synthesis is effectively solved, and an effective way is provided for improving the selectivity of the oxygen-containing compound.

The invention provides a reductive activation method for preparing a high-added-value chemical catalyst from synthesis gas and application of the high-added-value chemical catalyst. The method comprises the following steps: placing a cobalt-containing composite oxide in a reactor, and introducing inert gas to completely replace air; the inert gas is completely replaced in a reducing atmosphere, primary reduction treatment is carried out at the temperature of 170-200 DEG C, secondary reduction treatment is carried out at the temperature of 210-260 DEG C, and third reduction treatment is carried out at the temperature of 270-340 DEG C; and activating the reduced cobalt-containing catalyst to obtain the cobalt carbide catalyst. According to the present invention, the rapid carbonization and the size stability of the Co phase can be achieved so as to achieve the one-step synthesis of the olefin product from the synthesis gas, such that the high conversion efficiency, the excellent comprehensive catalytic performance and the high olefin selectivity in the product distribution are provided, the obvious inactivation phenomenon does not occur in the catalyst activity within 2000 h, and the product distribution is more economical.

The present invention is a lithium-sulfur battery positive electrode material and its preparation method and application. The present invention first uses graphene oxide and a compound containing cobalt ions as raw materials to obtain a cobalt complex-coated reduced graphene precursor by reflux reaction; then adopts a CVD method to obtain a cobalt carbide-modified reduced graphene-carbon nanotube composite material, and finally uses a melt-diffusion method to uniformly distribute sulfur nanoparticles on the surface of the cobalt carbide-modified graphene-carbon nanotube composite material to obtain a cobalt carbide-modified graphene-carbon nanotube / sulfur (Co2C@RGO-CNT / S) composite material. The composite material of the present invention has the advantages of large specific surface area, porous structure, and high conductivity as a lithium-sulfur battery positive electrode material. Applying it to a lithium-sulfur battery can significantly improve the cycle performance and rate performance of the positive electrode material, so as to effectively solve the problem of too fast capacity decay occurring during the electrode reaction. The present invention is simple and easy to implement and can be applied to engineering production.