Production process capable of continuously synthesizing methanol

Abstract

The invention discloses a production process capable of continuously synthesizing methanol, and belongs to the technical field of methanol synthesis. A main catalytic active component Cu / ZnO is loaded by using hollow mesoporous manganese dioxide, and then a UiO-66 organic framework is used for coating, so that the Cu / ZnO coated HMnO2coated UiO-66 catalyst is prepared. Wherein the hollow mesoporous manganese dioxide increases the dispersibility of Cu, enhances the moderately strong alkaline sites on the surface of the catalyst, enhances the catalytic activity, and improves the stability of the catalyst and the loading capacity of Cu / ZnO at the same time. Unsaturated Zr sites in the UiO-66 have a synergistic catalysis effect, so that the catalytic activity of the catalyst can be effectively improved, and the UiO-66 enhances the chemical stability of the catalyst and enhances the heat resistance and hydrolysis resistance at high temperature; and the method has a good application prospect in actual industrial production.

Description

Technical Field

[0001] The invention belongs to the technical field of methanol synthesis, and particularly relates to a production process for sustainable methanol synthesis. Background Art

[0002] Methanol, the simplest saturated monohydric alcohol, is highly volatile and a key raw material in organic chemical industry. Thermal catalytic hydrogenation of CO2 to methanol is an important catalytic reaction that converts CO2 into methanol. This method holds great promise as a sustainable green chemical technology. CO2 hydrogenation to methanol is exothermic and reduces disorder. Its side reaction, the reverse water-gas reaction, is thermodynamically favorable and maintains disorder. High pressure and low temperature thermodynamically favor the conversion of CO2 to methanol. Due to the thermodynamic stability and chemical inertness of CO2, reaction temperatures above 240°C are believed to favor the activation of CO2 molecules. However, excessively high reaction temperatures can intensify the reaction toward CO production, resulting in reduced methanol selectivity. Excessively high operating pressures can also increase economic costs. Therefore, in addition to carefully controlling reaction conditions, designing catalysts with high catalytic performance for CO2 hydrogenation to methanol is crucial.

[0003] Industrial methanol production uses syngas (CO / CO₂ / H₂) as its raw material, primarily using a Cu / ZnO / Al₂O₃ catalyst in a fixed-bed reactor. This catalyst combines copper as the active component and zinc as a promoter. The synergistic effect between the two is key to its high activity. Specifically, ZnO stores overflow hydrogen and promotes reactions at Cu active sites. The dispersion of Cu and the density of Cu-Zn active sites determine the catalyst's activity. Alumina, as a support, provides a scaffold for the active species. The catalyst reaches its highest activity when the active species adheres uniformly to the highly dispersed support surface as a monolayer, maximizing its effective utilization. These copper-based catalysts exhibit excellent methanol synthesis activity at relatively low pressures and temperatures, along with high carbon conversion and low product impurity content. Consequently, they have been widely used. However, the high exothermicity of the methanol synthesis reaction can easily lead to copper sintering in the copper-based catalyst, resulting in catalyst deactivation and significantly shortening its service life.

[0004] Patent application CN102500382A discloses a methanol synthesis catalyst and its preparation method. The catalyst is composed of copper, zinc, aluminum oxides, and titanium dioxide. The methanol synthesis method described in the application consists of two steps: the first step is to form an aluminum precipitate using a single-component precipitation method; the second step is to form a co-precipitate of copper, zinc compounds, and titanium dioxide using a co-precipitation method under ultrasonic conditions; the final step is to mix the two precipitates, age them, filter, wash, dry, and calcine them. The methanol catalyst synthesized in this application has good low-temperature activity, good thermal stability, and high methanol selectivity. However, this type of catalyst may be susceptible to sintering and deactivation in the reaction atmosphere due to the influence of water, thus affecting catalytic activity. Summary of the Invention

[0005] The object of the present invention is to provide a production process for sustainable methanol synthesis for efficiently synthesizing methanol.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A production process for sustainable methanol synthesis comprises the following steps:

[0008] In the first step, synthesis gas containing CO2 / H2 feed gas is heated to a high temperature and passed through a first reactor equipped with a Cu / ZnO@HMnO2@UiO-66 catalyst to produce methanol. The resulting mixed gas containing synthesis gas and methanol vapor is then passed through a first gas-to-gas heat exchanger to exchange heat with synthesis gas containing CO2 / H2 feed gas to be fed into the first reactor. After cooling, it is passed through a second reactor also equipped with a Cu / ZnO@HMnO2@UiO-66 catalyst to further produce methanol.

[0009] In the second step, the synthesis gas with a higher methanol concentration after the reaction is cooled and then enters the methanol separator to separate the methanol. The synthesis gas after methanol separation is mixed with the CO2 / H2 raw gas to obtain a synthesis gas containing CO2 / H2 raw gas, which is heated again and enters the first reactor.

[0010] Furthermore, the molar ratio of hydrogen to carbon in the CO2 / H2 raw gas is 2 to 3:1; and the heating temperature is 200 to 250°C.

[0011] Furthermore, the inlet and outlet temperatures of the first reactor are 220-230°C; the inlet and outlet temperatures of the second reactor are 200-210°C.

[0012] Furthermore, the Cu / ZnO@HMnO2@UiO-66 catalyst is prepared by the following steps:

[0013] (1) Anhydrous ethanol, ultrapure water and ammonia water were mixed and stirred uniformly, and then tetraethoxysilane was added, and the mixture was heated and stirred for 12 to 14 hours to obtain silica; the synthesized silica was used as a template, placed in an ultrasonic environment, and a 3 mg / mL potassium permanganate solution was added dropwise, and the ultrasonication was continued for 6 hours; the mixture was centrifuged and washed with water, and finally dispersed in a 2 mol / L NaCO3 solution and stirred at 55 to 60°C overnight, and centrifuged and washed with water to obtain hollow mesoporous manganese dioxide nanospheres (HMnO2);

[0014] (2) Cu(NO3)2 . 3H2O, Zn(NO3)2 . 6H2O and HMnO2 were uniformly dispersed in deionized water, and 2 mol / L sodium carbonate solution was slowly added dropwise to adjust the pH to 9±0.2. The mixture was stirred at 65-70°C for 3-4 hours, allowed to stand for 4-5 hours, washed and dried, and calcined at 250-280°C for 4-5 hours to obtain Cu / ZnO@HMnO2.

[0015] (3) Cu / ZnO@HMnO2, dimethylformamide, zirconium tetrachloride, terephthalic acid, acetic acid and deionized water were mixed and stirred with ultrasound to fully dissolve; after reacting at 110-120°C for 22-24 hours, the mixture was washed and dried to obtain a Cu / ZnO@HMnO2@UiO-66 catalyst.

[0016] Furthermore, the dosage ratio of the anhydrous ethanol, ultrapure water, ammonia water, tetraethoxysilane, potassium permanganate solution and NaCO3 solution is 25-30 mL: 1-1.5 mL: 2-3 mL: 1.2-1.5 mL: 50-55 mL: 20-25 mL; and the heating and stirring temperature is 45-55°C.

[0017] Furthermore, the Cu(NO3)2 . 3H2O, Zn(NO3)2 . The usage ratio of 6H2O and HMnO2 is 1-1.1g:0.4-0.5g:0.3-0.4g.

[0018] Furthermore, the usage ratio of the Cu / ZnO@HMnO2, dimethylformamide, zirconium tetrachloride, terephthalic acid, acetic acid and deionized water is 0.6-1 g: 200-210 mL: 6-6.2 g: 4.2-4.4 g: 45-50 mL: 3-3.5 mL.

[0019] Beneficial effects of the present invention:

[0020] (1) The hollow mesoporous manganese dioxide nanospheres used in the present invention increase the dispersion of the active component metal Cu by adding the manganese dioxide component, improve the oxygen vacancy concentration of the catalyst, and enhance the medium-strong alkaline sites on the catalyst surface, which is beneficial to the adsorption and desorption of CO2 on the catalyst surface, thereby promoting the positive occurrence of the CO2 hydrogenation to methanol reaction; on the other hand, the manganese dioxide is prepared into a hollow mesoporous structure, which improves the stability of the catalyst, increases its own specific surface area, and is more conducive to the occurrence of the catalytic reaction; at the same time, it also increases the loading amount of Cu / ZnO.

[0021] (2) The UiO-66 used in the present invention has a unique three-dimensional structure, in which the Zr metal participates in the catalytic CO2 hydrogenation to methanol reaction and plays a co-catalytic role. On the one hand, the unsaturated Zr site has a synergistic catalytic effect, which can effectively improve the catalytic activity of the catalyst. On the other hand, UiO-66 enhances the chemical stability of the catalyst, greatly enhances the heat resistance at high temperatures, makes the catalyst less likely to sinter due to heat, and improves the dispersibility of the catalyst. UiO-66 and hollow mesoporous manganese dioxide protect the main active structure of the catalyst, control the size of the catalyst, and make it less likely to be decomposed by the water generated by the reaction, thereby reducing the degradation of the catalyst. DETAILED DESCRIPTION

[0022] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0023] Example 1

[0024] This embodiment provides a production process for sustainable methanol synthesis, comprising the following steps:

[0025] The first step is: (1) 25 mL of anhydrous ethanol, 1 mL of ultrapure water and 2 mL of ammonia water are mixed and stirred evenly, and then 1.2 mL of tetraethoxysilane is added, and the mixture is stirred at 45 ° C for 12 hours to obtain silica; the synthesized silica is used as a template, placed in an ultrasonic environment, and 50 mL of a 3 mg / mL potassium permanganate solution is added dropwise, and the ultrasonication is continued for 6 hours; the mixture is centrifuged and washed with water, and finally dispersed in 20 mL of a 2 mol / L NaCO3 solution and stirred at 55 ° C overnight, and centrifuged and washed with water to obtain hollow mesoporous manganese dioxide nanospheres (HMnO2);

[0026] (2) Cu(NO3)2 . 3H2O, Zn(NO3)2 .6H2O and HMnO2 were uniformly dispersed in deionized water, and 2 mol / L sodium carbonate solution was slowly added dropwise to adjust the pH to 9±0.2. The mixture was stirred at 65-70°C for 3-4 hours, allowed to stand for 4-5 hours, washed and dried, and calcined at 250-280°C for 4-5 hours to obtain Cu / ZnO@HMnO2.

[0027] (3) 0.8 g Cu / ZnO@HMnO2, 200 mL dimethylformamide, 6 g zirconium tetrachloride, 4.2 g terephthalic acid, 45 mL acetic acid, and 3 mL deionized water were mixed and stirred with ultrasonication to fully dissolve; after reacting at 110 °C for 24 h, the mixture was washed and dried to obtain the Cu / ZnO@HMnO2@UiO-66 catalyst.

[0028] In the second step, the synthesis gas containing CO2 / H2 feed gas (hydrogen-carbon molar ratio of 3:1) is heated to 200°C and methanol is generated through a first reactor equipped with a Cu / ZnO@HMnO2@UiO-66 catalyst. The resulting mixed gas containing synthesis gas and methanol vapor is heat exchanged with the synthesis gas containing CO2 / H2 feed gas to be entered into the first reactor through a first gas-to-gas heat exchanger. After cooling, methanol is further generated through a second reactor also equipped with a Cu / ZnO@HMnO2@UiO-66 catalyst. The inlet and outlet temperatures of the first reactor are controlled at 220-230°C; the inlet and outlet temperatures of the second reactor are controlled at 200-210°C.

[0029] In the third step, the synthesis gas with a high methanol concentration after the reaction is cooled and then enters the methanol separator to separate the methanol. The synthesis gas after methanol separation is mixed with the CO2 / H2 raw gas to obtain a synthesis gas containing CO2 / H2 raw gas, which is heated again to 200°C and enters the first reactor.

[0030] Example 2

[0031] The difference between this embodiment and embodiment 1 is that the "2 mL ammonia water" in the first step (1) is changed to "3 mL ammonia water".

[0032] The remaining raw materials and preparation process remain the same as in Example 1.

[0033] Example 3

[0034] The difference between this embodiment and embodiment 1 is that the step of "stirring at 45°C for 12 hours" in the first step (1) is changed to "stirring at 55°C for 12 hours".

[0035] The remaining raw materials and preparation process remain the same as in Example 1.

[0036] Example 4

[0037] The difference between this embodiment and embodiment 1 is that "0.8g Cu / ZnO@HMnO2" in the first step (3) is changed to "0.6g Cu / ZnO@HMnO2".

[0038] The remaining raw materials and preparation process remain the same as in Example 1.

[0039] Example 5

[0040] The difference between this embodiment and embodiment 1 is that "0.8g Cu / ZnO@HMnO2" in the first step (3) is changed to "1g Cu / ZnO@HMnO2".

[0041] The remaining raw materials and preparation process remain the same as in Example 1.

[0042] Example 6

[0043] The difference between this embodiment and embodiment 1 is that the "hydrogen-carbon molar ratio of 3:1" in the second step is changed to "hydrogen-carbon molar ratio of 2:1".

[0044] The remaining raw materials and preparation process remain the same as in Example 1.

[0045] Example 7

[0046] The difference between this embodiment and embodiment 1 is that "heating the synthesis gas to 200° C." in the second step is changed to "heating the synthesis gas to 250° C.".

[0047] The remaining raw materials and preparation process remain the same as in Example 1.

[0048] Comparative Example 1

[0049] Compared with Example 1, this comparative example differs in that step (1) in the first step is removed, and Mn(NO3)2 is added as a manganese source in (2). The specific implementation steps are as follows:

[0050] The first step, (1) weigh 1gCu(NO3)2 . 3H2O, 0.4gZn(NO3)2 . 6H2O and 0.3gMn(NO3)2 were uniformly dispersed in deionized water, and 2mol / L sodium carbonate solution was slowly added dropwise to adjust the pH to maintain at 9±0.2. The mixture was stirred at 65℃ for 3h, allowed to stand for 4h, washed and dried, and calcined at 250℃ for 4h to obtain Cu / ZnO / MnO x ;

[0051] (2) 0.8g Cu / ZnO / MnO x, 200 mL dimethylformamide, 6 g zirconium tetrachloride, 4.2 g terephthalic acid, 45 mL acetic acid and 3 mL deionized water were mixed, stirred and ultrasonicated to fully dissolve; after reacting at 110 ° C for 24 h, washed and dried to obtain Cu / ZnO / MnO x @UiO-66 catalyst.

[0052] The remaining raw materials and preparation process remain the same as in Example 1.

[0053] Comparative Example 2

[0054] Compared with Example 1, this comparative example differs in that step (1) in the first step is removed, and HMnO2 is not added in (2). The specific implementation steps are:

[0055] The first step, (1) weigh 1gCu(NO3)2 . 3H2O and 0.4gZn(NO3)2 . 6H2O was evenly dispersed in deionized water, and 2 mol / L sodium carbonate solution was slowly added dropwise to adjust the pH to 9±0.2. The mixture was stirred at 65℃ for 3 h, allowed to stand for 4 h, washed and dried, and calcined at 250℃ for 4 h to obtain Cu / ZnO.

[0056] (2) 0.8 g Cu / ZnO, 200 mL dimethylformamide, 6 g zirconium tetrachloride, 4.2 g terephthalic acid, 45 mL acetic acid, and 3 mL deionized water were mixed and stirred with ultrasonication to fully dissolve; after reacting at 110 °C for 24 h, the mixture was washed and dried to obtain the Cu / ZnO@UiO-66 catalyst.

[0057] The remaining raw materials and preparation process remain the same as in Example 1.

[0058] Comparative Example 3

[0059] Compared with Example 1, this comparative example is different in that step (3) in the first step is removed, and the specific implementation steps are as follows:

[0060] The first step is: (1) 25 mL of anhydrous ethanol, 1 mL of ultrapure water and 2 mL of ammonia water are mixed and stirred evenly, and then 1.2 mL of tetraethoxysilane is added, and the mixture is stirred at 45 ° C for 12 hours to obtain silica; the synthesized silica is used as a template, placed in an ultrasonic environment, and 50 mL of a 3 mg / mL potassium permanganate solution is added dropwise, and the ultrasonication is continued for 6 hours; the mixture is centrifuged and washed with water, and finally dispersed in 20 mL of a 2 mol / L NaCO3 solution and stirred at 55 ° C overnight, and centrifuged and washed with water to obtain hollow mesoporous manganese dioxide nanospheres (HMnO2);

[0061] (2) Weigh 1gCu(NO3)2 . 3H2O, 0.4gZn(NO3)2 .6H2O and 0.3gHMnO2 were uniformly dispersed in deionized water, and 2mol / L sodium carbonate solution was slowly added dropwise to adjust the pH to 9±0.2. The mixture was stirred at 65℃ for 3h, allowed to stand for 4h, washed and dried, and calcined at 250℃ for 4h to obtain Cu / ZnO@HMnO2.

[0062] The remaining raw materials and preparation process remain the same as in Example 1.

[0063] Comparative Example 4

[0064] The catalyst used in this comparative example is Cu / ZnO, and the specific implementation steps are as follows:

[0065] In the first step, the synthesis gas containing CO2 / H2 raw gas (hydrogen-carbon molar ratio of 3:1) is heated to 200°C, and methanol is generated through a first reactor equipped with a Cu / ZnO catalyst. The resulting mixed gas containing synthesis gas and methanol vapor is heat exchanged with the synthesis gas containing CO2 / H2 raw gas to be entered into the first reactor through a first gas-to-gas heat exchanger. After cooling, methanol is further generated through a second reactor also equipped with a Cu / ZnO catalyst; the inlet and outlet temperatures of the first reactor are controlled at 220-230°C; the inlet and outlet temperatures of the second reactor are controlled at 200-210°C.

[0066] In the second step, the synthesis gas with a high methanol concentration after the reaction is cooled and then enters the methanol separator to separate the methanol. The synthesis gas after methanol separation is mixed with the CO2 / H2 raw gas to obtain a synthesis gas containing CO2 / H2 raw gas, which is heated again to 200°C and enters the first reactor.

[0067] The remaining raw materials and preparation process remain the same as in Example 1.

[0068] The performance of the catalysts prepared in Examples 1 to 7 and Comparative Examples 1 to 4 was tested. The reaction pressure P was 4 MPa and the volume space velocity GHSV was 12000 h -1 ,

[0069] The results are shown in Table 1:

[0070] Table 1

[0071]

[0072]

[0073] As can be seen from Table 1, compared with Example 1, the difference between Examples 2 to 3 lies in the effect of pH and temperature on the synthesis of hollow mesoporous manganese dioxide. When the ammonia content is higher, the hydrolysis reaction of tetraethoxysilane is more complete, and the number of silica particles obtained is also more, but the particle size of silica will also become larger, which is not conducive to the subsequent synthesis of the catalyst. When the temperature is increased, although the silica obtained is smaller, the hydrolysis reaction of tetraethoxysilane is incomplete, and the number of silica particles is small, resulting in reagent waste. This will affect the synthesis of hollow mesoporous manganese dioxide nanospheres in the next step, thereby affecting the catalytic effect of the final catalyst. Compared with Example 1, the only difference between Examples 4 to 6 is that the raw material ratio varies within a reasonable range, which has little effect on the final result. Compared with Example 1, Example 7 has the following differences: on the one hand, the synthesis of methanol is an exothermic reaction, and too high a temperature is not conducive to the forward reaction, and too high a temperature is a higher burden on equipment and energy loss. Too high a temperature will accelerate the thermal decomposition of the catalyst, which is not conducive to the sustainable synthesis of methanol.

[0074] Compared with Example 1, Comparative Examples 1 to 2 are mainly reflected in the decrease in methanol space-time yield and the increase in catalyst conversion rate. This is because manganese oxide increases the dispersion of the active component metal Cu, increases the oxygen vacancy concentration of the catalyst, and enhances the medium-strong alkaline sites on the catalyst surface, which is conducive to the adsorption and desorption of CO2 on the catalyst surface, thereby promoting the positive occurrence of the CO2 hydrogenation to methanol reaction; and hollow mesoporous manganese dioxide improves the stability of the catalyst, increases its own specific surface area, and is more conducive to the occurrence of the catalytic reaction; at the same time, it also increases the loading capacity of Cu / ZnO. Compared with Example 1, in Comparative Example 3, the catalytic effect of the catalyst is reduced after the UiO-66 organic skeleton is not added. Under the influence of high temperature and water generated in the reaction, the decomposition of the catalyst is accelerated; in Comparative Example 4, compared with Example 1, the Cu / ZnO catalyst alone is very likely to produce sintering between components during the catalytic reaction, and the catalytic active sites are occupied by water molecules, thereby losing catalytic activity, which is not conducive to the sustainable synthesis of methanol.

[0075] In summary, the present invention provides a sustainable methanol synthesis production process with low CO2 conversion rate and catalyst conversion rate, high methanol space-time yield and methanol selectivity, which can be used for continuous methanol production and has good application prospects in actual production.

[0076] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0077] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A production process for sustainable methanol synthesis, characterized in that: The steps include: In the first step, synthesis gas containing CO2 / H2 feed gas is heated to a high temperature and passed through a first reactor equipped with a Cu / ZnO@HMnO2@UiO-66 catalyst to produce methanol. The resulting mixed gas containing synthesis gas and methanol vapor is then passed through a first gas-to-gas heat exchanger to exchange heat with synthesis gas containing CO2 / H2 feed gas to be fed into the first reactor. After cooling, it is passed through a second reactor also equipped with a Cu / ZnO@HMnO2@UiO-66 catalyst to further produce methanol. In the second step, the synthesis gas with a higher methanol concentration after the reaction is cooled and then enters the methanol separator to separate the methanol. The synthesis gas after methanol separation is mixed with the CO2 / H2 raw gas to obtain a synthesis gas containing CO2 / H2 raw gas, which is heated again and enters the first reactor.

2. A production process for sustainable methanol synthesis according to claim 1, characterized in that: The molar ratio of hydrogen to carbon in the CO2 / H2 raw gas is 2 to 3:1; the heating temperature is 200 to 250°C.

3. The process for producing sustainable methanol synthesis according to claim 1, characterized in that: The inlet and outlet temperatures of the first reactor are 220-230°C; the inlet and outlet temperatures of the second reactor are 200-210°C.

4. The process for producing sustainable methanol synthesis according to claim 1, characterized in that: The Cu / ZnO@HMnO2@UiO-66 catalyst is prepared by the following steps: (1) Anhydrous ethanol, ultrapure water and ammonia water are mixed and stirred uniformly, and then tetraethoxysilane is added, and heated and stirred for 12 to 14 hours to obtain silica; the synthesized silica is used as a template, placed in an ultrasonic environment, and a 3 mg / mL potassium permanganate solution is added dropwise, and the ultrasonication is continued for 6 hours; centrifugation and water washing are performed, and finally the mixture is dispersed in a 2 mol / L NaCO3 solution and stirred at 55 to 60°C overnight, and centrifugation and water washing are performed to obtain hollow mesoporous manganese dioxide nanospheres, wherein the hollow mesoporous manganese dioxide nanospheres are HMnO2; (2) Cu(NO3)2 . 3H2O, Zn(NO3)2 . 6H2O and HMnO2 were uniformly dispersed in deionized water, and 2 mol / L sodium carbonate solution was slowly added dropwise to adjust the pH to 9±0.

2. The mixture was stirred at 65-70°C for 3-4 hours, allowed to stand for 4-5 hours, washed and dried, and calcined at 250-280°C for 4-5 hours to obtain Cu / ZnO@HMnO2. (3) Cu / ZnO@HMnO2, dimethylformamide, zirconium tetrachloride, terephthalic acid, acetic acid and deionized water were mixed and stirred with ultrasound to fully dissolve; after reacting at 110-120°C for 22-24 hours, the mixture was washed and dried to obtain a Cu / ZnO@HMnO2@UiO-66 catalyst.

5. The process for producing sustainable methanol synthesis according to claim 4, characterized in that: The dosage ratio of the anhydrous ethanol, ultrapure water, ammonia water, tetraethoxysilane, potassium permanganate solution and NaCO3 solution is 25-30 mL: 1-1.5 mL: 2-3 mL: 1.2-1.5 mL: 50-55 mL: 20-25 mL; the heating and stirring temperature is 45-55°C.

6. The process for producing sustainable methanol synthesis according to claim 4, characterized in that: The Cu(NO3)2 . 3H2O, Zn(NO3)2 . The usage ratio of 6H2O and HMnO2 is 1-1.1g:0.4-0.5g:0.3-0.4g.

7. The process for producing sustainable methanol synthesis according to claim 4, characterized in that: The usage ratio of the Cu / ZnO@HMnO2, dimethylformamide, zirconium tetrachloride, terephthalic acid, acetic acid and deionized water is 0.6-1g:200-210mL:6-6.2g:4.2-4.4g:45-50mL:3-3.5mL.

Images