WO2023142671A1

WO2023142671A1 - Cu-al-ni-co-based catalyst, and preparation method therefor and use thereof

Info

Publication number: WO2023142671A1
Application number: PCT/CN2022/135790
Authority: WO
Inventors: 常帅; 李长东; 阮丁山; 蔡勇; 周游; 李强
Original assignee: 广东邦普循环科技有限公司; 湖南邦普循环科技有限公司; 湖南邦普汽车循环有限公司
Priority date: 2022-01-29
Filing date: 2022-12-01
Publication date: 2023-08-03
Also published as: GB202319447D0; GB2622722A8; CN114471574A; CN114471574B; GB2622722A

Abstract

Disclosed in the present application are a Cu-Al-Ni-Co-based catalyst, and a preparation method therefor and the use thereof. The composition of the Cu-Al-Ni-Co-based catalyst of the present application comprises CuO, Al₂O₃, Co₃O₄ and NiO. The preparation method for the catalyst comprises the following steps: dissolving copper and aluminum slag, which is generated during a lithium ion battery recovery process, in an acid, then adding an alkali for a co-precipitation reaction, separating out obtained precipitates, and then roasting same to obtain a Cu-Al-Ni-Co-based catalyst. The catalyst has abundant alkaline sites and active sites, has a simple and environmentally friendly preparation, has good catalytic activity and stability, can further realize resource cyclic regeneration, value addition and comprehensive utilization of waste battery materials and carbon dioxide, and is suitable for practical popularization and use.

Description

Cu-Al-Ni-Co based catalyst and its preparation method and application

technical field

The application relates to the technical field of battery material recycling, and in particular to a Cu-Al-Ni-Co-based catalyst and its preparation method and application.

Background technique

Due to the rapid development of industry, the emission of carbon dioxide in the atmosphere is increasing. To address the ever-increasing concentration of carbon dioxide, new methods are needed to capture, sequester and utilize carbon dioxide. At present, recycling and recycling of carbon dioxide has received extensive attention. Catalytic production of value-added products such as methane, synthesis gas, methanol, and dimethyl ether by hydrogenation of carbon dioxide is considered to be an effective way to utilize carbon dioxide. However, the catalysts for the hydrogenation of carbon dioxide to produce value-added products have the problems of high preparation costs, complicated processes, and poor selectivity. There is an urgent need to develop a green, environmentally friendly, simple, and low-cost preparation method.

The service life of lithium-ion batteries is about 3 to 20 years. With the increase in demand for lithium-ion batteries, the amount of waste battery recycling has also increased sharply. However, waste lithium-ion batteries are easy to cause environmental pollution, and how to deal with waste batteries on a large scale is a very challenging problem. At the same time, the copper-aluminum slag produced in the recycling process of waste lithium-ion battery materials usually contains elements such as Cu, Al, Ni and Co, and the recovery process of these metal elements is generally complicated and costly, which is not conducive to large-scale treatment and actual application.

Therefore, there is an urgent need to research and develop a green, environmentally friendly and economical approach that can not only recycle waste battery materials on a large scale, but also recycle carbon dioxide.

Contents of the invention

The following is an overview of the topics described in detail in this article. This summary is not intended to limit the scope of the claims.

In order to research and develop a green, environmentally friendly and economical method that can not only recycle waste battery materials on a large scale, but also recycle carbon dioxide, so as to solve the problem of recycling carbon dioxide and waste battery materials, one of the purposes of this application is to Provided is a Cu-Al-Ni-Co based catalyst.

The second purpose of the present application is to provide a method for preparing a Cu-Al-Ni-Co based catalyst.

The third purpose of the present application is to provide an application of the above-mentioned catalyst.

The technical scheme adopted in this application is:

In a first aspect, the present application provides a Cu-Al-Ni-Co based catalyst, the composition of which includes CuO, Al ₂ O ₃ , Co ₃ O ₄ and NiO.

Preferably, the CuO contains (-1 1 1) crystal planes, and the interplanar spacing of the crystal planes is 2-3 nm.

Preferably, the mass percent of Cu, Al, Ni and Co atoms in the Cu-Al-Ni-Co based catalyst is:

Cu: 20%-24%;

Al: 22%-26%;

Ni: 1%-2%;

Co: 13%-18%.

Further preferably, the mass percentages of Cu, Al, Ni and Co atoms in the Cu-Al-Ni-Co-based catalyst are:

Cu: 21%-23%;

Al: 24%-25%;

Ni: 1.2%-1.6%;

Co: 15%-16%.

Preferably, the composition of the Cu-Al-Ni-Co-based catalyst further includes MnO ₂ , Li ₂ O and Fe ₂ O ₃ .

Specifically, the Cu-Al-Ni-Co-based catalyst contains a variety of active components, which can have abundant basic sites and sites for reduction reactions, which is conducive to the adsorption and desorption of hydrogen, and is suitable for Catalytic hydrogenation reaction system.

In a second aspect, the present application provides a method for preparing the Cu-Al-Ni-Co-based catalyst, comprising the following steps:

Dissolving the copper-aluminum slag produced in the lithium-ion battery recycling process in acid, adding alkali to carry out co-precipitation reaction, and then separating the obtained precipitate and roasting to obtain a Cu-Al-Ni-Co-based catalyst.

Preferably, the preparation method of described Cu-Al-Ni-Co based catalyst comprises the following steps:

Dissolving the copper-aluminum slag produced in the lithium-ion battery recycling process in an acid solution, adding an alkali solution for co-precipitation reaction, and then separating the obtained precipitate and roasting to obtain a Cu-Al-Ni-Co-based catalyst.

Preferably, the mass ratio of copper, aluminum, cobalt and nickel in the copper-aluminum slag is (8-30):(10-30):(5-20):1.

Further preferably, the mass ratio of copper, aluminum, cobalt and nickel in the copper-aluminum slag is (10-25):(15-26):(6-18):1.

Preferably, the acid is one or more of nitric acid, hydrochloric acid, sulfuric acid, phosphoric acid and hydrofluoric acid.

Further preferably, the acid is one or more of nitric acid, hydrochloric acid and sulfuric acid.

Preferably, the alkali is one or more of ammonia water, sodium hydroxide, potassium hydroxide, sodium bicarbonate and sodium carbonate.

Further preferably, the alkali is one or more of ammonia water, sodium hydroxide and potassium hydroxide.

Preferably, the acid solution has a concentration of 1-3 mol/L, and the alkali solution has a concentration of 1-3 mol/L.

Preferably, the co-precipitation reaction is carried out at a temperature of 50° C. to 80° C. and a pH of 5 to 11, and the reaction time is 1 h to 5 h.

Further preferably, the co-precipitation reaction is carried out at a temperature of 30° C. to 90° C. and a pH of 6 to 8, and the reaction time is 2 h to 3 h.

Preferably, the co-precipitation reaction process further includes a stirring step.

Preferably, after the co-precipitation reaction, a step of standing still is included, the standing is carried out at 15° C. to 35° C., and the standing time is 1 h to 3 h.

Preferably, the specific operation of the separation is suction filtration.

Preferably, after the precipitate is separated, washing and drying are also included.

Preferably, the drying temperature is 50°C-100°C.

Preferably, the calcination temperature is 300°C-700°C, and the calcination time is 0.5h-5h.

Further preferably, the calcination temperature is 400°C-600°C, and the calcination time is 1h-3h.

Preferably, the heating rate of the calcination is 5°C·min ^-1 to 10°C·min ^-1 .

In a third aspect, the application provides a method for synthesizing methanol with carbon dioxide, which includes the following steps:

1) The Cu-Al-Ni-Co-based catalyst described in the first aspect is loaded into a reactor, and a reducing gas is introduced for activation treatment;

2) Feed carbon dioxide and hydrogen into the reactor for catalytic reaction to obtain methanol.

Preferably, the Cu-Al-Ni-Co-based catalyst described in step 1) needs to be sieved, granulated, and diluted before being loaded into the reactor.

Preferably, the sieve used for the sieving has a mesh size of 10-100 mesh.

Preferably, the specific operation of the dilution is to mix the diluent with the Cu-Al-Ni-Co based catalyst.

Preferably, the mass ratio of the diluent to the Cu-Al-Ni-Co-based catalyst is 1:1˜1:5.

Further preferably, the mass ratio of the diluent to the Cu-Al-Ni-Co-based catalyst is 1:2˜1:3.

Preferably, the diluent has a mesh number of 10-100 mesh.

Preferably, the diluent is at least one of quartz sand, molecular sieve and activated carbon.

Further preferably, the diluent is quartz sand.

Preferably, the flow rate of the reducing gas in step 1) is 30mL·min ^-1 to 100mL·min ^-1 .

Further preferably, the flow rate of the reducing gas in step 1) is 40mL·min ^-1 to 60mL·min ^-1 .

Preferably, the reducing gas in step 1) is hydrogen and/or carbon monoxide.

Further preferably, the reducing gas in step 1) is hydrogen.

Preferably, the temperature of the activation treatment in step 1) is 300°C-400°C.

Further preferably, the temperature of the activation treatment in step 1) is 320°C-350°C.

Preferably, the heating rate of the active treatment in step 1) is 5°C·min ^-1 to 10°C·min ^-1 .

Preferably, the time for the active treatment in step 1) is 0.5h-5h.

Further preferably, the time for the active treatment in step 1) is 1-3 hours.

Preferably, the volume ratio of carbon dioxide and hydrogen in step 2) is 1:1˜1:10.

Further preferably, the volume ratio of carbon dioxide and hydrogen in step 2) is 1:2˜1:5.

Preferably, the volume concentration of carbon dioxide in the catalytic reaction in step 2) is 5%-30%.

Further preferably, the volume concentration of carbon dioxide in the catalytic reaction in step 2) is 10%-20%.

More preferably, the volume concentration of carbon dioxide in the catalytic reaction in step 2) is 15%.

Preferably, protective gas is also passed into the reactor described in step 2).

Preferably, the protective gas is one or more of helium, nitrogen, argon and neon.

Preferably, the space velocity of the catalytic reaction in step 2) is 5000h ^-1 -20000h ^-1 .

Further preferably, the space velocity of the catalytic reaction in step 2) is 6000h ^-1 -15000h ^-1 .

Preferably, the pressure of the catalytic reaction in step 2) is 1MPa-5MPa.

Preferably, the temperature of the catalytic reaction in step 2) is 200°C-300°C.

Further preferably, the temperature of the catalytic reaction in step 2) is 240°C-280°C.

More preferably, the temperature of the catalytic reaction in step 2) is 260°C.

Preferably, gas chromatography is used to monitor the reactants and products of the catalytic reaction.

The beneficial effect of this application is:

The Cu-Al-Ni-Co-based catalyst of the present application contains abundant active components and reaction sites (including multiple basic sites), and has a good catalytic effect as a catalyst for hydrogenation of carbon dioxide, and the catalyst is It is prepared from waste battery materials, realizes recycling of waste battery materials, has the advantages of simple preparation, green and environmental protection, and is suitable for practical application.

Specifically:

(1) This application recycles waste battery materials into catalyst products, realizing the effect of turning waste into treasure.

(2) The Cu-Al-Ni-Co-based catalyst of the present application is rich in reduction sites and alkaline sites, and has better activity for converting carbon dioxide into methanol, which can recycle waste battery materials and can Carbon dioxide is comprehensively utilized and resynthesized into chemical value-added products (methanol fuel).

(3) The Cu-Al-Ni-Co-based catalyst of the present application can catalyze the hydrogenation of carbon dioxide to produce methanol (fuel) at 200°C to 300°C, and has a higher reaction temperature at 240°C to 280°C Selectivity and better stability (ie methanol selectivity is about 75%, and shows good stability under the reaction conditions of 260° C. for 60 hours).

(4) The method for synthesizing methanol with carbon dioxide provided by the present application includes activation treatment, which is beneficial to improving the stability of the Cu-Al-Ni-Co-based catalyst in the catalytic reaction, thereby increasing the service life of the catalyst.

Other aspects will be apparent to others upon reading and understanding the drawings and detailed description.

Description of drawings

The accompanying drawings are used to provide a further understanding of the technical solutions herein, and constitute a part of the description, and are used together with the embodiments of the application to explain the technical solutions herein, and do not constitute limitations to the technical solutions herein.

FIG. 1 is an XRD pattern of the Cu-Al-Ni-Co-based catalyst in Example 1.

FIG. 2 is a TEM image of the Cu-Al-Ni-Co-based catalyst in Example 1. FIG.

3 is an HRTEM image of the Cu-Al-Ni-Co-based catalyst in Example 1.

Figure 4 is the reaction temperature- _CO2 conversion rate curve of the Cu-Al-Ni-Co based catalyst in Example 1.

5 is the reaction temperature-methanol yield curve of the Cu-Al-Ni-Co-based catalyst in Example 1.

Fig. 6 is the reaction temperature-methanol selectivity test result of the Cu-Al-Ni-Co based catalyst in Example 1.

Fig. 7 is the stability test result of the Cu-Al-Ni-Co based catalyst in Example 1.

Detailed ways

The content of the present application will be described in further detail below through specific examples.

Example 1

A preparation method of Cu-Al-Ni-Co based catalyst, comprising the following steps:

1) Dissolve 20g of copper-aluminum slag in 3mol L ^-1 nitric acid to form a mixed solution containing Cu-Al-Ni-Co (referred to as solution A); then configure 3mol L ^-1 ammonia solution (referred to as solution B) ;

2) Using the co-precipitation method, drop solution A and solution B into the beaker at the same time in a water bath at 80°C for reaction, and control the dropping speed of solutions A and B to keep the pH of the reaction solution at about 8, and place the solution in After stirring continuously in a water bath for 3 hours, it was left to stand at room temperature for 1 hour to obtain a suspension;

3) Suction filter the suspension obtained in step 2), wash with deionized water, dry at 90°C for 12 hours, roast at 600°C for 3 hours, then granulate and sieve (20-40 mesh) to obtain Cu-Al -Ni-Co based catalysts.

A method for catalytically synthesizing methanol with carbon dioxide, comprising the following steps:

1) Preactivation of the catalyst: Mix 1.5g Cu-Al-Ni-Co-based catalyst and 4.5g inert silica sand (20-40 mesh) evenly, put them into the reactor together, feed hydrogen, and treat at 300°C for 1 hour ( The heating rate is 10°C·min ^-1 , the gas flow rate is 50mL·min ^-1 );

2) Preparation of methanol: feed a mixed gas of 15% CO ₂ , 45% H ₂ and Ar into the reactor, control the space velocity to 12000h ^-1 , the pressure to 5Mpa, the heating rate of 5°C·min ^-1 , and Under the temperature condition of 200℃～300℃, methanol can be produced.

Characterization and Performance Testing:

1) The element content of the Cu-Al-Ni-Co-based catalyst in Example 1 was obtained by ICP-MS, and the results are shown in Table 1.

It can be seen from Table 1 that there are more Cu (22.66%), Al (24.13%), Co (15.17%) and a small amount of Ni (1.4%) in the catalyst prepared by recycling copper-aluminum slag, because _H2 mainly is decomposed on Cu and Ni, while _CO2 is mainly activated on Al and Co, which indicates that the Cu-Al-Ni-Co-based catalyst of the present application is beneficial for the conversion of carbon dioxide to methanol.

The elemental content of the Cu-Al-Ni-Co-based catalyst in Table 1 Example 1

2) The X-ray diffraction spectrum (XRD pattern) of the Cu-Al-Ni-Co-based catalyst in Example 1, as shown in FIG. 1 .

It can be seen from Figure 1 that the components in the Cu-Al-Ni-Co-based catalyst mainly exist in the form of oxides, and the diffraction peaks appearing at 35.5°, 38.75° and 48.75° belong to CuO (PDF#72-0629 ); the diffraction peaks at 35.16°, 58.24° and 68.18° are attributed to Al ₂ O ₃ (PDF#75-0786); NiO (PDF#87-0712) and Co ₃ O ₄ can also be observed in detail (PDF #76-1802) characteristic diffraction peak. This shows that the present application can obtain a Cu-Al-Ni-Co-based catalyst containing CuO, Co ₃ O ₄ , Al ₂ O ₃ and NiO by using the copper-aluminum slag of the waste battery. Among them, CuO and NiO species have dissociation effect on the hydrogen gas on the catalyst after carbon dioxide reduction, while Al ₂ O ₃ and Co ₃ O ₄ have adsorption effect on reactant CO ₂ . Further analysis, from a kinetic point of view, enhanced _CO2 adsorption and hydrogen dissociation are beneficial to the formation of methanol.

3) The transmission electron microscope (TEM) image and high magnification transmission electron microscope (HRTEM) image of the Cu-Al-Ni-Co-based catalyst in Example 1 are shown in Figure 2 and Figure 3, respectively.

It can be seen from Figure 2 and Figure 3 that the dark part in Figure 2 is mainly the area where CuO is distributed, and it can be observed that CuO is distributed on the Cu-Al-Ni-Co-based catalyst, and the dispersion of CuO in the catalyst is good, which helps In the dissociation of _H2 , thereby promoting the synthesis of methanol. For the analysis of the dark area, the obvious (-1 1 1) crystal plane of CuO can be observed in Figure 3, and the crystal plane spacing is 2.522nm, which further verifies that the Cu-Al-Ni-Co-based catalyst has CuO phase with good dispersion and crystallinity.

4) Using the reaction conditions of the method for catalytically synthesizing methanol with carbon dioxide, the temperature was raised from 200°C to 300°C, and the catalytic activity of the Cu-Al-Ni-Co-based catalyst in Example 1 was measured under different reaction temperature conditions, (active Evaluation indicators are: _CO2 conversion rate, methanol yield and methanol selectivity), and the results are shown in Figure 4, Figure 5 and Figure 6. The Cu-Al-Ni-Co-based catalyst was placed at 260° C. and reacted continuously for 60 hours to obtain the stability test results of the Cu-Al-Ni-Co-based catalyst in Example 1, as shown in FIG. 7 .

It can be seen from Figure 4, Figure 5 and Figure 6 that: under the condition of 200°C to 260°C, with the increase of reaction temperature, the conversion rate of _CO2 and methanol yield increased rapidly; under the condition of 260°C to 300°C , with the increase of reaction temperature, the _CO2 conversion rate showed a slowly increasing trend ( _CO2 conversion rate was 9.8% at 300 °C), and the methanol yield showed a slow decreasing trend (260 °C methanol yield rate was 64.8%) ; Under the condition of 200°C to 300°C, the selectivity of methanol continues to decrease. In general, Cu-Al-Ni-Co-based catalysts are more economical to synthesize methanol at about 260°C (the selectivity of methanol is about 75%) . Under the reaction conditions of 260°C, although the conversion rate of _CO2 is 9.8%, the catalyst has a methanol yield of 64.8%, which can achieve the effect of capturing carbon dioxide and regenerating it into methanol products with higher economic value.

It can be seen from Figure 7 that the Cu-Al-Ni-Co based catalyst was tested for 60 hours at 260°C for 60 hours, and it was found that the stability of the catalyst was good, and the conversion rate of _CO2 was maintained at about 8%, and the production of methanol was stable. The production rate can also be stably maintained at about 75%, which is suitable for the actual production and application of methanol.

Example 2

1) Dissolve 20g of copper-aluminum slag in 2mol L ^-1 nitric acid to form a mixed solution containing Cu-Al-Ni-Co (referred to as solution A); then configure 2mol L ^-1 ammonia solution (referred to as solution B) ;

2) Using the co-precipitation method, drop solution A and solution B into the beaker at the same time in a 60°C water bath for reaction, and control the dropping speed of solutions A and B to keep the pH of the reaction solution at about 7, and place the solution in After continuous stirring in a water bath for 2 hours, it was left to stand at room temperature for 1 hour to obtain a suspension;

3) Suction filter the suspension obtained in step 2), wash with deionized water, dry at 100°C for 12 hours, and roast at 500°C for 3 hours, then granulate and sieve (20-40 mesh) to obtain Cu-Al -Ni-Co based catalysts.

1) Pre-activation of the catalyst: mix 1g of Cu-Al-Ni-Co-based catalyst and 3g of inert silica sand (20-40 mesh) evenly, put them into the reactor together, pass in hydrogen, and treat at 300°C for 1 hour (heating rate 10°C·min ^-1 , the gas flow rate is 50mL·min ^-1 );

2) Preparation of methanol: feed a mixed gas of 15% CO ₂ , 45% H ₂ and Ar into the reactor, control the space velocity to 10000h ^-1 , the pressure to 3Mpa, the heating rate of 5°C·min ^-1 , and Under the temperature condition of 200～300℃, methanol can be produced.

After testing, the phase composition and performance of the catalyst prepared in this example and the catalyst prepared in Example 1 (the yield of methanol at 260° C. is 63.5%) are very close.

Example 3

1) Dissolve 20g of copper-aluminum slag in 1mol L ^-1 nitric acid to form a mixed solution containing Cu-Al-Ni-Co (referred to as solution A); then configure 1mol L ^-1 ammonia solution (referred to as solution B) ;

2) Adopt co-precipitation method, under 50 ℃ water bath, react by dropping solution A and solution B into the beaker at the same time, and control the dropping speed of solutions A and B, keep the pH of the reaction solution at about 6, and put After the solution was continuously stirred in a water bath for 3 hours, it was left standing at room temperature for 2 hours to obtain a suspension;

3) Suction filter the suspension obtained in step 2), wash with deionized water, dry at 80°C for 12 hours, roast at 400°C for 3 hours, then granulate and sieve (20-40 mesh) to obtain Cu- Al-Ni-Co based catalysts.

1) Preactivation of the catalyst: Mix 0.5g of the catalyst and 1.5g of inert silica sand (20-40 mesh) evenly, put them into the reactor together, pass in hydrogen, and treat at 300°C for 2 hours (the heating rate is 10°C·min ^{- 1} , the gas flow rate is 50mL·min ^-1 );

2) Preparation of methanol: feed a mixed gas of 15% CO ₂ , 45% H ₂ and Ar into the reactor, control the space velocity to 6000h ^-1 , the pressure to 2Mpa, the heating rate of 10°C·min ^-1 , and Under the temperature condition of 200～300℃, methanol can be produced.

After testing, the phase composition and performance of the Cu-Al-Ni-Co-based catalyst prepared in this example and the catalyst prepared in Example 1 (methanol yield at 260° C. is 64.2%) are very similar.

comparative example

The difference between the preparation method of a Cu-Al-Ni-Co-based catalyst provided in this comparative example and the examples is that the copper-aluminum slag is simply activated and treated, and it specifically includes the following steps:

After mixing 1.5g of copper-aluminum slag and 4.5g of inert silica sand (20-40 mesh) evenly, put them into the reactor together, inject hydrogen gas, and treat at 300°C for 1 hour (the heating rate is 10°C·min ^-1 , and the gas flow rate is 50mL·min ^- ¹ ) to obtain the catalyst.

The performance test of the catalyst in this comparative example is carried out, and the specific test conditions are the same as those for methanol production in the examples.

Through the performance test, it can be seen that there is no methanol in the collected reaction products, and the conversion rate of _CO2 is zero, which shows that the catalyst obtained by only using simple activation treatment in the comparative example does not have the ability to capture, collect, store and convert _CO2 , What's more, it is impossible to regenerate waste battery materials (copper and aluminum slag), and it is impossible to obtain a catalyst that can convert carbon dioxide into methanol fuel.

If there is no special instructions, the amount of reactants (hydrogen and carbon dioxide) and product (methanol) in the method for the catalytic synthesis of methanol using carbon dioxide and the performance test of the comparative examples in Examples 1 to 3, all adopt a TCD (thermal conductivity detector) ) and FID (hydrogen flame detector) gas chromatograph (Agilent Technologies 6890 USA) test and analysis.

The above-mentioned embodiment is a preferred implementation mode of the application, but the implementation mode of the application is not limited by the above-mentioned embodiment, and any other changes, modifications, substitutions, combinations, Simplifications should be equivalent replacement methods, and all are included in the protection scope of the present application.

Claims

A Cu-Al-Ni-Co based catalyst, wherein the composition of the Cu-Al-Ni-Co based catalyst includes CuO, Al 2 O 3 , Co 3 O 4 and NiO.
Cu-Al-Ni-Co-based catalyst according to claim 1, wherein: the mass percentage of Cu, Al, Ni and Co atoms in the Cu-Al-Ni-Co-based catalyst is:

Cu: 20%-24%;

Al: 22%-26%;

Ni: 1%-2%;

Co: 13%-18%.
The Cu-Al-Ni-Co-based catalyst according to claim 1 or 2, wherein: the composition of the Cu-Al-Ni-Co-based catalyst further includes MnO 2 , Li 2 O and Fe 2 O 3 .
A kind of preparation method of Cu-Al-Ni-Co base catalyst, wherein, comprise the following steps:

Dissolving the copper-aluminum slag produced in the lithium-ion battery recycling process in acid, adding alkali to carry out co-precipitation reaction, and then separating the obtained precipitate and roasting to obtain a Cu-Al-Ni-Co-based catalyst.
The preparation method of Cu-Al-Ni-Co-based catalyst according to claim 4, wherein: the mass ratio of copper, aluminum, cobalt and nickel in the copper-aluminum slag is (8～30): (10～30) :(5～20):1.
The preparation method of Cu-Al-Ni-Co-based catalyst according to claim 4, wherein: the acid is one or more of nitric acid, hydrochloric acid, sulfuric acid, phosphoric acid and hydrofluoric acid; the alkali is ammonia water , sodium hydroxide, potassium hydroxide, sodium bicarbonate and sodium carbonate in one or more.
The preparation method of Cu-Al-Ni-Co based catalyst according to claim 6, wherein: the concentration of the acid solution is 1-3 mol/L, and the concentration of the alkali solution is 1-3 mol/L.
The method for preparing a Cu-Al-Ni-Co-based catalyst according to any one of claims 4 to 6, wherein: the co-precipitation reaction is carried out at a temperature of 30°C to 90°C and a pH of 5 to 11, The reaction time is 1h～5h.
The preparation method of Cu-Al-Ni-Co based catalyst according to any one of claims 4 to 6, wherein: the temperature of the calcination is 300°C-700°C, and the calcination time is 0.5h-5h.
A method for synthesizing methanol with carbon dioxide, comprising the steps of:

1) The Cu-Al-Ni-Co-based catalyst described in any one of claims 1 to 3 is loaded into a reactor, and a reducing gas is introduced to carry out activation treatment;

2) Feeding carbon dioxide and hydrogen into the reactor for catalytic reaction to obtain methanol.
The method for synthesizing methanol with carbon dioxide according to claim 9, wherein: the activation treatment temperature in step 1) is 300°C-400°C; the catalytic reaction temperature in step 2) is 200°C-300°C.