90 results about "Cobalt carbide" patented technology

The invention discloses a preparation method and an application of a flexible catalytic material for water electrolysis, and belongs to the technical field of hydrogen production by water electrolysis. The preparation method comprises the following steps: (1) preparing cobalt-based Prussian blue analogue nanoparticles; (2) dispersing the cobalt-based Prussian blue analogue nanoparticles in an organic solvent, then adding polyacrylonitrile to prepare a spinning solution, and electrostatically spinning to prepare a Co-PBA / PAN composite nanofiber membrane; (3) pre-oxidizing the Co-PBA / PAN composite nanofiber membrane, and then carbonizing in an inert atmosphere to prepare the flexible catalytic material for water electrolysis. In the catalytic material for water electrolysis prepared in the invention, cobalt carbide is uniformly dispersed in porous carbon fiber, so that catalytic sites are increased. Meanwhile, the porous carbon fiber provides carriers for the catalytic sites and enhancesthe conductivity, thereby improving the problems of easy falling and loss of conventional powder catalytic materials; and a production method is easy and convenient, environment-friendly and safe, and can achieve large-area continuous production.

The invention discloses a method for manufacturing nanometer tungsten / cobalt carbide composite powder. The method includes steps of firstly, dissolving, by mass, 55-92% of water-soluble tungsten salt, 3-40% of water-soluble cobalt salt, 3-6% of water-soluble carburizing and nodulizing agents and 0.1-2% of water-soluble composite grain growth inhibitors into water with the mass 3-5 times that of a mixture of the water-soluble tungsten salt, the water-soluble cobalt salt, the water-soluble carburizing and nodulizing agents and the water-soluble composite grain growth inhibitors to prepare mixed aqueous solution; secondly, adding nanometer carbon black accounting for 1-10% of the total mass of the aqueous solution into the mixed aqueous solution obtained in the first step, stirring the nanometer carbon black in the mixed aqueous solution at the rate of 10-30 revolutions per minute for 30-60 minutes so that the nanometer carbon black can be uniformly mixed in the mixed aqueous solution; thirdly, performing quick low-temperature spray drying for mixed aqueous solution obtained in the second step to obtain precursor powder of ultrafine tungsten and cobalt composite salt; and fourthly, performing reduction synthesis and carbon conditioning at the temperature ranging from 900 DEG C to 1000 DEG C for the precursor powder obtained in the third step to manufacture tungsten / cobalt carbide composite powder materials with nanostructures.

The invention discloses a porous carbon loaded double-crystalline phase cobalt-based fischer-tropsch symthesis catalyst and preparation method and application thereof. The catalyst takes cobalt as an active component, porous carbon as a carrier and FCC and HCP crystalline phase cobalt as active phases, the mass content of the cobalt is 29.0%-30.8%, and the mass ratio of the HCP crystalline phase to FCC crystalline phase of the cobalt is 0.42-0.97:1. During preparation, a cobalt-contained metal organic skeleton is taken as a sacrificial template which is pyrolyzed under inert atmosphere, porous carbon loaded cobalt carbide intermediates by adopting carbonization of carbon monoxide, and a catalyst precursor is obtained by gas passivation treatment; the catalyst is obtained after the precursor is subjected to hydrogenation activation treatment. The cobalt metal active phases include the FCC and HCP crystalline phases which is high in activity and good in C5+selectivity when used in fischer-tropsch synthesis reaction, high C5+space time yield is specifically achieved, and C5+products are mainly composed of gasoline and diesel compositions.

The invention provides a method for catalytic decomposition of hydrogen sulfide by a composite type catalyst. The method comprises the following steps of directly catalyzing the hydrogen sulfide to decompose by the composite type catalyst under a microwave field to produce hydrogen gas and sulphur, wherein the composite type catalyst comprises carbon compounded transition metal carbide being at least one of molybdenum carbide, cobalt carbide, iron carbide, tungsten carbide and carrier silicon carbide subjected to alkali treatment. The method comprises the following concrete steps of filling the composite type catalyst into a quartz tube of a microwave reactor to form a microwave catalyst bed layer; then, introducing mixed gas containing hydrogen sulfide so that the gas-solid phase microwave catalyst reaction is performed; the direct decomposition of hydrogen sulfide is realized. The method has various advantages that the reaction conditions are mild; the parameters are controllable; the operation is convenient; the composite type catalyst and the microwave achieve the cooperated effects, so that the decomposition efficiency of the hydrogen sulfide is higher, and the like.

The invention belongs to the technical field of nano materials and photocatalysis, and particularly relates to a nitrogen-doped carbon-coated Mn2Co2C composite material which is prepared by the methodcomprising the following steps: reacting soluble positive bivalent cobalt salt, positive bivalent manganese salt and cobalt potassium cyanide to obtain precipitate, and reacting the precipitate at high temperature under the protection of N2 atmosphere to obtain the nitrogen-doped carbon-coated Mn2Co2C composite material. The nitrogen-doped carbon-coated Mn2Co2C composite material disclosed by theinvention can be used as a hydrogen production cocatalyst to accept electrons and promote a hydrogen evolution reaction, Mn2Co2C@C nanoparticles as a cocatalyst are loaded on the surface of g-C3N4 toobtain a g-C3N4 / Mn2Co2C@C composite photocatalyst material, and the g-C3N4 / Mn2Co2C@C composite photocatalyst material shows efficient activity of photocatalytic decomposition of water to produce hydrogen.

Cryptomelane-type manganese oxide octahedral molecular sieves (OMS-2) supported Fe and Co catalysts are utilized in a method for producing hydrocarbons by a Fischer-Tropsch mechanism. The hydrocarbon producing method includes providing a catalyst of a manganese oxide-based octahedral molecular sieve nanofibers with an active catalyst component of at least one of iron, cobalt, nickel, copper, manganese, vanadium, zinc, and mixtures thereof, and further containing an alkali metal. The formation of iron carbides and cobalt carbides by exposing the catalyst to conditions sufficient to form those carbides is also taught. After the catalyst has been appropriately treated, a carbon source and a hydrogen source are provided and contacted with the catalyst to thereby form a hydrocarbon containing product. The catalyst have high catalytic activity and selectivity (75%) for C2+ hydrocarbons in both CO hydrogenation and CO2 hydrogenation. Highly selective syntheses of high value jet fuel, C2-C6 alkenes, C2-C6 carboxylic acids; α-hydroxylic acids and their derivatives have been realized by tuning the oxidation ability of OMS-2 supports and by doping with Cu2+ ions.

The invention relates to a mining hard alloy, in particular to a hard alloy specially applied to a rock drilling tool. The hard alloy is mainly prepared from tungsten carbide and cobalt carbide by sintering, and the hard alloy is characterized in that the whole hard alloy is divided into more than two layers from inside to outside, cobalt contents and particle sizes of the layers are different. Thus the hard alloy has the optimal abrasion resistance and toughness, rock drilling efficiency and service life are effectively improved. Meanwhile, key position effect of cobalt is fully exerted, and useful effect of the hard alloy is played, thus the effect of cobalt saving is achieved.

A process for preparing a cobalt-containing hydrocarbon synthesis catalyst includes, in a carbide formation step, treating an initial catalyst precursor comprising a catalyst support supporting cobalt and / or a cobalt compound, with a CO containing gas at a temperature T. T is from 200° C. to 280° C. The cobalt or cobalt compound is converted to cobalt carbide thereby obtaining a cobalt carbide containing catalyst precursor. The CO containing gas (when it contains H2) does not have a CO to H2 molar ratio equal to or less than 33:1. The carbide formation step is carried out under non-oxidative conditions. In a subsequent activation step, the cobalt carbide containing catalyst precursor is subjected to treatment with a hydrogen containing gas at a temperature T2. T2 is at least 300° C. The cobalt carbide is converted to cobalt metal thereby activating the cobalt carbide containing catalyst precursor and obtaining a cobalt-containing hydrocarbon synthesis catalyst.