CN1260118C - Preparation for metal sulfide - Google Patents

Abstract

The present invention relates to a method for preparing metal sulfide, elemental sulfur and metal or metal protosulfide are placed in an organic solvent together and react for 6 to 120 hours at the temperature of 100 to 500 DEG C and under the atmospheric pressure of 1 to 800 to obtain metal sulfide. The method of the present invention has the obvious advantages that compared with a method for synthesizing the metal and the elemental sulfur at high temperature, the risk is obviously reduced, a large amount of toxic gas is not used or generated, the raw material has low cost and can be easily obtained, the production technology is simple, the reaction conditions can be controlled easily, the present invention is favorable to the mass production of metal sulfide material, etc. The present invention can be used for preparing the metal sulfide only containing a single metal element or composite metal sulfide containing various metal elements. The prepared sulfide product is usually superfine powder whose fundamental particle dimension is less than 5 mu, and the prepared sulfide product can also be directly used as a catalyst and battery material.

Description

Preparation method of metal sulfide

technical field

The invention relates to a method for preparing metal sulfides.

Background technique

Many metal sulfides exhibit excellent photoelectric, thermoelectric, electromagnetic and semiconducting physical properties, and have a wide range of uses in physical electrical and magnetic devices. Similarly, many metal sulfides (such as sulfides of Mo, W, etc.) have excellent catalytic properties in chemistry; in addition, some sulfides (such as sulfides of Fe, Co, Ni) can also be used as positive catalysts for medium and low temperature batteries. Negative material. However, due to the limitations of the synthesis method, sulfide materials are difficult to mass-produce.

Generally speaking, metal sulfides can be prepared by mixing and reacting elemental metal and sulfur together. In many cases, the preparation of sulfides (such as many transition metal sulfides) is generally carried out at higher temperatures because solidification reactions are difficult to occur at low temperatures. Its reaction process is:

To avoid oxidation by oxygen, the reactor needs to be sealed. Due to the strong corrosiveness of sulfur vapor at high temperatures, generally only quartz reactors can be used. In this method, the reactant is generally sealed in a quartz reactor in a vacuum environment and burned at a high temperature. Because, on the one hand, the sulfur vapor pressure is too high at high temperature; on the other hand, the reaction process between metal and sulfur vapor is very violent and often explosive, and quartz is not a good pressure-resistant material, so this method is very dangerous. The complicated operation and huge potential danger make this method unsuitable for mass production of metal sulfides.

Vapor pressure is lower and easily reduced sulfide replaces elemental sulfur and is sometimes used to prepare sulfide with better stability (as described in the patent of CN: 1086493A), which can reduce the requirement of sulfidation reaction on the reactor material, but Obviously, the preparation method is complicated, and unnecessary metal impurity elements are introduced into the product.

The desired product can be obtained by vulcanizing metal oxides and metal salts in hydrogen sulfide at 200-500 ° C; some metal sulfides can be prepared by depositing water-soluble salts of metals and water-soluble salts of sulfur in aqueous phase, but in many cases The product is often amorphous and easily contains OH groups. It is possible to obtain various sulfides and complex sulfides by treating this product as a precursor in high-temperature hydrogen sulfide gas (Inorganic Chemistry, 42, 1764 (2003)). The products synthesized by these methods are often poor in crystallinity, and involve a large amount of toxic gas H ₂ S to be used. A similar method is to prepare metal sulfides by reacting metal salts with Na ₂ S ₂ etc. above 300°C, and the products and by-products are mixed together to form a solid solution (J.Chem.SoC.DaltonTrans., 12, 1872 (2001) In addition, it also includes the very similar chloride method (Inorganic Chemistry, 20, 2631 (1981)), sulfate method (Inorganic Chemistry, 23, 872 (1984)) and other sulfide preparation methods.

Thermal decomposition of sulfur-containing metal-organic compounds (J. Solid State chem., 101, 115 (1992); 109, 70 (1994)) is also a common method for preparing a small amount of sulfide, which obviously has many disadvantages such as expensive raw materials.

As catalysts and battery materials, pyrite sulfides (FeS ₂ , CoS _{2 ,} etc.) are produced using a method called hydrothermal method. For example, the method of JP-A-59-183831 synthesized FeS ₂ by hydrothermal method using ferrous sulfate heptahydrate, sodium sulfide and sulfur as raw materials. Similarly, the literature (Journal of Beijing University of Science and Technology, 18(1), 69(1996)) synthesized FeS ₂ by ferrous sulfate heptahydrate, sodium thiosulfate and sulfur in deionized water at 200°C, and found that the reaction was affected by pH The value has a great influence and should not be controlled, and the product recovery rate is low. One disadvantage of the aqueous solution method for preparing metal sulfides is that metal sulfides are prone to hydrolysis.

Correspondingly, the solvothermal method has also been used to prepare metal sulfides. The literature (J.Solid State Chem., 146, 484 (1999)) reported a method, using metal nitrate, chloride salt or sulfate and excess S as raw materials, in an organic solvent at 120 ℃ solvothermal reaction preparation Transition metal sulfides of a variety of single metal elements. This reaction utilizes the disproportionation reaction of sulfur to realize the sulfidation of metal elements, but at the same time it also leads to the generation of a large amount of toxic gases such as SCl ₂ . Literature (Mater.Chem.Phys., 66(1), 97(2000)) reported that FeS ₂ and CoS ₂ were prepared by solvothermal method of anhydrous metal chloride and Na ₂ S ₃ in an organic solvent at 180°C. Raw materials are not easy to obtain in France.

At room temperature, for example, mixing copper powder with solid sulfur powder hardly reacts; but if sulfur is dissolved in acetone, it can react with metallic copper to form Cu ₂ S. Obviously, dissolving in an organic solvent can increase the reactivity of S, but on the one hand, at normal temperature and pressure, this solid-liquid phase reaction is difficult to complete, and it is difficult to obtain high-purity products; on the other hand, many pyrite-type sulfides (FeS ₂ , CoS ₂ , NiS _{2 ,} etc.) cannot be produced by this method at normal temperature and pressure. Therefore, it is impossible to use this method to prepare a large amount of metal sulfides under normal conditions.

Invention content:

The purpose of the present invention is to provide a method for preparing metal sulfides, which is simple, low in production cost, relatively friendly to the environment and conducive to mass production.

The technical scheme provided by the invention is: the preparation method of metal sulfide, elemental sulfur and metal (Me) or metal subsulfide (MeS _x ) are placed in an organic solvent, and the components are made by solvothermal method React at 100-500° C. and 20-800 atmospheres for 6-120 hours to prepare metal sulfide MeS _y (where y>0, 0<x<y). Among them, the metal low sulfide means that the stoichiometric content of sulfur is lower than that of the target metal sulfide. The "metal (Me)" mentioned in the present invention may only contain a single metal element, or may be a combination of two or more metal elements. For example, metals can include simple substances, alloys, metal mixtures, etc., while metal sulfides can be sulfides with only one metal element, or composite metal sulfides containing two or more metal elements. Metal sulfides refer to metal sulfides composed of metal and sulfur through bonding.

The metal contains at least one or more transition metal elements.

The basic particle size of the above-mentioned metal or metal subsulfide is less than 50 microns.

The organic solvent used can be chloralkane (such as trichloromethane, carbon tetrachloride etc.), chloroalkene (such as dichloroethylene), containing benzene ring class (such as benzene, toluene etc.), sulfur-containing organic solvent (such as carbon disulfide, etc.) and at least one of various ethers, ketones, alcohols, glycerol, pyridines, and ionic liquids.

The added amount of sulfur in the above raw materials is just enough to form MeS _y or in excess, preferably the added amount of elemental sulfur is 1.01-1.03 times of the chemical reaction amount.

The time for carrying out the reaction by the solvothermal method described therein is no more than 5 days.

The prepared sulfide MeS _y includes a sulfide catalyst containing transition metal elements and a pyrite-type transition metal dichalcogenide.

Compared with the prior art, the present invention mainly uses the high reactivity of dissolved sulfur at a certain temperature and pressure to directly react with metals or metal low sulfides, thereby preparing some functional metals in a milder environment. Sulfide material. The method of the present invention has the following advantages: compared with the direct high-temperature synthesis method of metal and sulfur, the risk of the implementation process is significantly reduced; it does not involve the use or generation of toxic gases in large quantities; the cost of raw materials is low and easy to obtain; the production process is simple and the reaction conditions are easy to control ; Conducive to the mass production of metal sulfide materials and other obvious advantages. The invention can be used to prepare metal sulfides containing only a single metal element or composite metal sulfides composed of multiple metal elements.

Description of drawings

Accompanying drawing is the X-ray analysis curve of several metal sulfides prepared by the inventive method. Among them (a) SnS, (b) NiS ₂ , (c) CoS ₂ , (d) FeS ₂ , (e) Fe _0.7 Co _0.3 S ₂ .

Detailed ways

The raw materials used to prepare metal sulfides in the present invention include metal components and elemental sulfur, wherein the metal components are defined in the present invention as metal elements, alloys, metal mixtures, etc., and can also be lower than the target product sulfur content Other forms of metal sulfides and complex metal sulfides are readily prepared. Put the metal component powder together with elemental sulfur and an organic solvent capable of dissolving sulfur in a high-pressure reactor, and heat it in the temperature range of 100-500 ° C. During the heating period, 1-800 atmospheres of pressure are applied to the contents of the reactor. Pressure, through the solvothermal reaction, metal sulfides or composite metal sulfides are relatively easy to produce.

When feeding the reactor, the metal component powder and the elemental sulfur do not have to be uniformly mixed. Since the organic solvent can dissolve sulfur, after the reaction starts, the organic solvent transports the sulfur to the place where it is needed, thus ensuring the on-demand supply of elemental sulfur. This supply of sulfur is similar to the supply of oxygen in the blood, with high efficiency and uniformity.

The reaction process is equivalent to a solid-liquid phase reaction under heat and pressure. On the one hand, the dissolved sulfur under heat and pressure has high reactivity and can directly react with metal components to form the target product. The pressurized environment is conducive to the solid-phase diffusion of sulfur to achieve complete vulcanization of the metal component powder. The use of metal component powders with a smaller size (less than 50 microns) and prolonged reaction time are beneficial to obtaining high-purity target metal sulfides. The entire reaction time varies depending on the properties of the target product and raw materials, and generally does not exceed 5 days.

Metal sulfides are generally insoluble in organic solvents and are not hydrolyzed, so they exist in the form of solids in the reactor, which is easy to achieve product separation. The product prepared by the invention is metal sulfide powder, the basic particle size of which is generally less than 5 microns, and can be directly used as catalyst or battery material. In the present invention, when preparing metal sulfides, the elemental sulfur is sometimes appropriately excessive, and the excess sulfur is generally dissolved in an organic solvent and can be removed by filtration. However, due to the large specific surface area of the product, it is easy to absorb a small amount of organic solvent and elemental sulfur. Therefore, the product is generally washed with a solvent such as carbon disulfide to remove the remaining organic solvent and elemental sulfur.

When preparing composite metal sulfides, if metal is used as the raw material, the various metal elements in the raw material must be highly dispersed, for example, alloy powder or a very uniformly dispersed metal powder mixture is used as the metal component raw material.

Another way is to use highly dispersed composite sulfides with low sulfur content as the metal component raw materials for preparing composite metal sulfides. In particular, for example, when preparing _{FexCo (1-x) S2} (0<x<1), highly dispersed composite metal-sulfide _{FexCo (1-x)} S can be obtained by co-deposition in aqueous solution (0<x<1) as the metal component raw material. Although some results show that the _{FexCo (1-x)} S (0<x<1) prepared by this aqueous co-deposition method may contain a small amount of hydroxyl groups, the experimental results show that this does not affect the preparation of the target product.

Since the present invention can adopt the compact solid particle packing mode when the raw materials are added into the autoclave, the single-pot reaction output can be improved. The method of the invention can be used for mass production of metal sulfides.

Embodiments of the present invention are described in detail below.

Example 1: Place 16 grams of elemental copper powder and elemental sulfur in an atomic ratio of 2:1 in a 30ml autoclave, add acetone to 90% of the reactor, and keep the reactor at 110°C for 3 days at 20 atmospheres. After natural cooling, the product powder was taken out by filtration, washed with carbon disulfide, and dried to obtain 15.3 g of Cu ₂ S. X-ray analysis showed that the product was Cu ₂ S.

Example 2: Put 12.8 grams of elemental Sn powder and elemental sulfur in an atomic ratio of 1:1.03 in a 30ml autoclave, and add toluene to 90% of the reactor. The reaction kettle was kept at a constant temperature of 220°C for 3 days under about 300 atmospheres. After natural cooling, the product powder was filtered out, washed with carbon disulfide, and dried to obtain 12.2 grams of SnS. X-ray analysis results showed that the product was SnS.

Example 3: 10 grams of metal nickel powder and 11.3 grams of elemental sulfur were placed in a 50 ml autoclave, and toluene was added to reach 90% of the reactor. The reaction kettle was kept at about 300 atmospheres at 220°C for 5 days. After natural cooling, the product powder was filtered out, washed with carbon disulfide, and dried to obtain 20.2 g of NiS ₂ . X-ray and EDX analysis showed that the product was NiS ₂ .

Example 4: NiS black precipitate was obtained by dissolving NiCl ₂ .6H ₂ O and Na ₂ S.9H ₂ O in aqueous solution, which was filtered and dried to obtain self-made NiS. 36.9 grams of self-made NiS powder and 13.3 grams of elemental sulfur were placed in a 100ml autoclave, and toluene was added to 90% of the reactor. The reaction kettle was kept at about 200 atmospheres at 180°C for 5 days. After natural cooling, the product powder was filtered out, washed with carbon disulfide, and dried to obtain 47.8 g of NiS ₂ . X-ray and EDX analysis showed that the product was NiS ₂ .

Example 5: Prepare CoS according to the method in Example 3. 14.7 g of CoS and 5.3 g of elemental sulfur were placed in a 100 ml autoclave, and toluene was added to 90% of the reactor. The reaction kettle was kept at a constant temperature of 250°C at about 400 atmospheres for 5 days. After natural cooling, the product powder was filtered out, washed with carbon disulfide, and dried to obtain 18.4 g of CoS ₂ . X-ray and EDX analysis showed that the product was CoS ₂ .

Example 6: CoS was prepared according to the method in Example 3. 14.7 g of CoS and 5.3 g of elemental sulfur were placed in a 100 ml autoclave, and toluene was added to 90% of the reactor. The reaction kettle was kept at about 800 atmospheres at 180°C for 5 days. After natural cooling, the product powder was filtered out, washed with carbon disulfide, and dried to obtain 18.4 g of CoS ₂ . X-ray and EDX analysis showed that the product was CoS ₂ .

Example 7: Prepare FeS according to the method in Example 3 (because FeS is easily oxidized, appropriate inert gas protection measures should be taken during preparation). 21.4 g of FeS and 8.0 g of elemental sulfur were placed in a 50 ml autoclave, and toluene was added to 90% of the reactor. The reaction kettle was kept at a constant temperature of about 300 atmospheres for 5 days. After natural cooling, the product powder was filtered out, washed with carbon disulfide, and dried to obtain 27.7 g of FeS ₂ . X-ray and EDX analysis showed that the product was FeS ₂ . .

Example 8: Preparation of Fe _0.7 Co _0.3 S by co-deposition in aqueous solution, 10 grams of Fe _0.7 Co _0.3 S and 3.7 grams of elemental sulfur were placed in a 30 ml autoclave, and toluene was added to 90% of the reactor. The reaction kettle was kept at a constant temperature of 250°C at about 400 atmospheres for 5 days. After natural cooling, the product powder was filtered out, washed with carbon disulfide, and dried to obtain 12.5 grams of Fe _0.7 Co _0.3 S ₂ composite sulfide. The X-ray analysis showed that the product was sulfur iron Ore structure, EDX analysis shows that the iron-cobalt stoichiometric ratio is 2.33±0.05.

Claims (8)

1. The preparation method of the metal sulfide is characterized by comprising the following steps: and putting the elemental sulfur and the metal or the metal low-sulfide together into an organic solvent, and reacting for 6-120 hours at 100-500 ℃ under 20-800 atmospheric pressure to obtain the metal sulfide.

2. The method of claim 1, wherein: the metal is a single metal element or a composition of two or more metal elements; the metal sulfide is a sulfide of one metal element or a composite metal sulfide of two or more metal elements.

3. The method of claim 2, wherein: the composition of two or more metal elements is an alloy or a metal mixture.

4. The process according to claim 1, 2 or 3, wherein: the metal includes at least one and more transition metal elements.

5. The process according to claim 1, 2 or 3, wherein: the primary particle size of the metal or metal oligosulfide is less than 50 microns.

6. The process according to claim 1, 2 or 3, wherein: the organic solvent is one or more of chloroalkane, chloroolefin, benzene ring-containing, sulfur-containing organic solvent, and ether, ketone, alcohol, glycerol, pyridine or ionic liquid organic solvent.

7. The process according to claim 1, 2 or 3, wherein: the amount of elemental sulfur added is either a chemically reactive amount or an excess amount.

8. The method of claim 7, wherein: the addition amount of the elemental sulfur is 1.01-1.03 times of the chemical reaction amount.