8 results about "Cobalt carbide" patented technology

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.

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 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.