CoP / mos2-c hollow composite piezoelectric material, preparation method thereof and application thereof in catalytic desorption of carbon dioxide

Abstract

The application discloses a CoP / MoS2-C hollow composite piezoelectric material and a preparation method and application thereof in carbon dioxide catalytic desorption, and the preparation of the CoP / MoS2-C comprises the following steps: in the presence of triethylamine, hexachlorocyclotriphosphazene, bisphenol S and ZIF-67 nanomaterials are subjected to condensation reaction in a solvent under stirring, and the polyphosphazene PZS generated in the reaction is wrapped on the surface of the ZIF-67; the obtained ZIF-67@PZS composite material is placed in a tube furnace and subjected to high-temperature calcination under a nitrogen atmosphere to obtain a hollow CoP / Co2P-C material, then the S source and the Mo source are dispersed in deionized water and stirred uniformly, and then subjected to hydrothermal reaction, and finally, the CoP / MoS2-C hollow composite piezoelectric material is obtained through washing and drying in sequence. The CoP / MoS2-C catalyst prepared by the application can accelerate the desorption rate of CO2 of organic amine, improve the regeneration efficiency of the organic amine loaded with CO2, reduce the regeneration energy consumption, and solve the technical bottleneck of the organic amine capturing CO2.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of catalysis, and particularly relates to a CoP / MoS2-C hollow composite piezoelectric material, a preparation method thereof and application thereof in catalytic desorption of carbon dioxide. BACKGROUND

[0002] The chemical absorption method has become a mainstream technology for CO2 capture due to its mature basic absorbent reaction mechanism. However, the traditional organic amine absorption method faces a significant bottleneck: the thermal decomposition of carbamate requires high temperature regeneration of 110-130 DEG C, which not only leads to thermal degradation of amine solvents, but also easily produces by-products. Therefore, reducing the regeneration temperature has become a research focus for promoting the industrialization of carbon capture technology. Emerging piezoelectric catalysis technology, especially high-efficiency molybdenum-based catalytic materials, provides a potential breakthrough to solve this problem and shows good application prospects.

[0003] MoS2 has been widely used in many catalytic fields due to its suitable energy band structure, high energy conversion efficiency, and rich edge active sites. However, natural MoS2 exhibits semiconductor properties, and its basal plane has high inertness, which seriously restricts its large-scale application as a catalyst. At present, how to effectively activate the inert basal plane and greatly improve the electrical conductivity has become a key problem to be solved. Only by breaking through these bottlenecks can the application potential of MoS2 in the field of catalysis be further expanded, so that it can play a greater role in CO2 capture.

[0004] Therefore, it is of great significance to develop MoS2 materials derived from MOFs with specific physical and chemical properties, improve the electrical conductivity of MoS2, and apply it to the catalytic desorption of CO2. The successful development of such materials is expected to help achieve efficient and green CO2 capture and promote carbon capture technology to be more environmentally friendly and energy-saving, and contribute to the global fight against climate change. SUMMARY

[0005] In view of the above technical problems existing in the prior art, the purpose of the present application is to provide a CoP / MoS2-C hollow composite piezoelectric material, a preparation method thereof and application thereof in catalytic desorption of carbon dioxide. The CoP / MoS2-C catalyst prepared by the present application can accelerate the desorption rate of CO2 of organic amine, improve the regeneration efficiency of CO2-loaded organic amine, reduce the regeneration energy consumption, and solve the technical bottleneck of organic amine CO2 capture.

[0006] This invention encapsulates a highly cross-linked polyphosphazene (PZS) shell onto the surface of synthesized ZIF-67, forming a core-shell ZIF-67@PZS composite material. Through a pyrolysis process, the core-shell ZIF-67@PZS composite material is gradually transformed into a hollow Co2P / CoP-C material with micro-mesoporous macroporous characteristics. The PZS shell transforms into a micro-mesoporous carbon shell, introducing additional N, P, and S dopants into the material. Porous carbon materials derived from metal-organic frameworks were successfully prepared under different carbonization temperatures. Thiourea was selected as the sulfur source, and ammonium molybdate as the molybdenum source. Molybdenum sulfide composite materials with different ratios were prepared using a hydrothermal method.

[0007] The technical solution adopted in this invention is as follows:

[0008] A method for preparing a CoP / MoS2-C hollow composite piezoelectric material for catalytic desorption of carbon dioxide includes the following steps:

[0009] Step 1: Hexachlorocyclotriphosphazene, bisphenol S and ZIF-67 nanomaterials were stirred together in a solvent, and triethylamine was added. A condensation reaction was carried out under stirring. The resulting polyphosphazene PZS was coated on the surface of ZIF-67. After the reaction was completed, the product was collected by centrifugation and dried to obtain the core-shell ZIF-67@PZS composite material.

[0010] Step 2: The ZIF-67@PZS composite material obtained in Step 1 is placed in a tube furnace and calcined at high temperature under a nitrogen atmosphere to obtain hollow CoP / Co2P-C material.

[0011] Step 3: Disperse the CoP / Co2P-C material, S source, and Mo source obtained in Step 2 in deionized water, stir evenly, transfer the mixture to a high-pressure reactor, seal the high-pressure reactor and carry out hydrothermal reaction, and finally wash and dry in sequence to obtain CoP / MoS2-C hollow composite piezoelectric material, thus completing the preparation.

[0012] Furthermore, in step 1, the molar ratio of hexachlorocyclotriphosphazene to bisphenol S is 1:2.5-3, and the ratio of the total amount of hexachlorocyclotriphosphazene and bisphenol S to the mass of ZIF-67 is 1 mol: 80-100 g.

[0013] Furthermore, in step 1, the total amount of hexachlorocyclotriphosphazene and bisphenol S is in the ratio of the volume of triethylamine to 2-4 mmol: 1 mL; the condensation reaction in step 1 is carried out at room temperature for 10-20 h.

[0014] Furthermore, in step 1, the solvent is methanol, and the dispersion concentration of ZIF-67 nanomaterials in the solvent is 2-5 g / L.

[0015] Furthermore, in step 2, the high-temperature calcination temperature is 900-1000℃, and the calcination time is 1-4 hours.

[0016] Furthermore, in step 3, the S source is thiourea, the Mo source is ammonium molybdate, and the molar ratio of the S source to the Mo source is 8-10:1; the ratio of the total amount of S source and Mo source to the mass of CoP / Co2P-C material is 1 mol: 4-8 g.

[0017] Furthermore, in step 3, the hydrothermal reaction temperature is 180-220℃, and the reaction time is 20-30h.

[0018] This invention also discloses the application of the CoP / MoS2-C hollow composite piezoelectric material as a catalyst in the catalytic desorption of carbon dioxide, and the application method includes the following steps:

[0019] S1: Pass CO2 into an aqueous solution of organic amines containing primary and tertiary amines;

[0020] S2: After CO2 absorption in step S1, liquid-liquid phase separation is performed, and the CO2-enriched phase solution is collected.

[0021] S3: The CoP / MoS2-C catalyst is added to the CO2-enriched phase solution, and the reaction desorbs CO2 at 90~95 °C to regenerate the organic amine.

[0022] Further, in step S1, the organic amine aqueous solution contains TETA and DEEA, the molar ratio of TETA and DEEA is 0.5~2:3, preferably 1:3, and the total amine concentration of the organic amine aqueous solution is 2~6 M, preferably 4 M.

[0023] Furthermore, in step S2, the amount of CO2 absorbed in the organic amine aqueous solution is greater than or equal to 0.75 mol CO2 / mol amine solution.

[0024] Furthermore, in step S3, the amount of catalyst added to the CO2 enriched phase solution is 0.5-3 mg / mL, preferably 1 mg / mL.

[0025] Compared with the prior art, the beneficial effects of the present invention are mainly reflected in:

[0026] 1) The CoP / MoS2-C material of the present invention can induce a piezoelectric effect through mechanical stirring, generate a built-in electric field, accelerate carrier migration and reduce charge transfer impedance, and effectively improve the CO2 desorption rate.

[0027] 2) The CoP / MoS2-C material of this invention is used in the two-phase solvent regeneration process represented by TETA-DEEA, which can effectively improve the problems of low CO2 desorption efficiency and high regeneration energy consumption, so that the peak CO2 desorption rate can be increased by 2.98 times and the heat load is reduced by 74.58% compared with the uncatalyzed case.

[0028] 3) The CoP / MoS2-C material of this invention has high catalytic stability and can be recycled. After the catalyst has undergone ten cycles, the CO2 desorption capacity of the biphase amine solution using CoP / MoS2-C is still 1.76 times that of the uncatalyzed case. Attached Figure Description

[0029] Figure 1 The images show XRD comparisons of intermediate products obtained under different pyrolysis conditions in Examples 1-4 of this invention.

[0030] Figure 2a The XRD pattern of the intermediate product CoP / Co2P-C obtained at a pyrolysis temperature of 900℃ in Example 3 is shown.

[0031] Figure 2b The image shows the XRD pattern of the final product CoP / MoS2-C obtained at a pyrolysis temperature of 900℃ in Example 3.

[0032] Figure 3 This is a TEM image of the intermediate product CoP / Co2P-C obtained at a pyrolysis temperature of 900°C in Example 3.

[0033] Figure 4 This is a TEM image of the final product, the CoP / MoS2-C composite material, obtained at a pyrolysis temperature of 900°C in Example 3.

[0034] Figure 5 This is an EDS image of the final product, the CoP / MoS2-C composite material, obtained at a pyrolysis temperature of 900°C in Example 3.

[0035] Figure 6 This describes the change in CO2 loading in the amine solution over time under different catalyst cycle numbers.

[0036] Figure 7 These are the results of the highest CO2 desorption rate and the relative heat load at different number of cycles of the catalyst.

[0037] Figure 8 This is a graph showing the relationship between the CO2 desorption rate of CoP / Co2P-C obtained at different pyrolysis temperatures and the heating time. Detailed Implementation

[0038] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0039] Example 1: A method for preparing a CoP / MoS2-C hollow composite piezoelectric material, specifically as follows:

[0040] 1) Accurately weigh 146 mg of Co(NO3)2·6H2O and 2 mg of hexadecyltrimethylammonium bromide (CTAB), and completely dissolve them in 5 ml of deionized water to prepare solution A. Separately, completely dissolve 2.27 g of 2-methylimidazole in 35 ml of deionized water to obtain solution B. Quickly pour solution A into solution B, and then stir the mixture for 40 min. After stirring, collect the reaction product by centrifugation, and wash the product several times with ethanol to remove impurities. Finally, place the product in a vacuum drying oven and dry it at 60 ℃ for 12 h to obtain ZIF-67 nanocubes.

[0041] 2) Accurately weigh 30 mg of hexachlorocyclotriphosphazene (HCCP) and 60 mg of bisphenol S, and dissolve them in 2 ml of methanol to prepare solution A. Then dissolve 30 mg of ZIF-67 nanocubes in 8 ml of methanol to obtain solution B. Quickly pour solution A into solution B and stir the mixture for 10 min. Afterward, slowly add 100 µl of triethylamine to the mixture using a pipette, and continue stirring at room temperature for 15 h to allow the reaction to proceed fully. After the reaction is complete, collect the product by centrifugation and dry it overnight in a vacuum oven to obtain the core-shell ZIF-67@PZS composite material.

[0042] 3) The prepared core-shell structured ZIF-67@PZS composite material was placed in a tube furnace and heated from room temperature to the pyrolysis temperature of 700℃ at a heating rate of 5℃ / min under a nitrogen atmosphere. This temperature was then maintained at the pyrolysis temperature for 2 h. During this process, the material underwent a series of physical and chemical changes, after which it was cooled to room temperature. Following the above process, a series of hollow CoP / Co2P-C composite materials at different pyrolysis temperatures were obtained.

[0043] 4) Weigh out 72 mg of CoP / Co2P-C, 890 mg of thiourea, and 235 mg of ammonium molybdate sequentially, and add them to 33 ml of deionized water. Stir rapidly to ensure thorough mixing. After ultrasonically dispersing the mixture for 30 min, transfer it to a 100 mL high-pressure reactor lined with polytetrafluoroethylene. Seal the reactor and heat it to 200 °C for a hydrothermal reaction for 24 h. After the hydrothermal reaction, obtain the product by centrifugation and dry it in a vacuum oven to obtain the CoP / MoS2-C composite material.

[0044] Example 2: A method for preparing a CoP / MoS2-C hollow composite piezoelectric material. The method steps are repeated in Example 1, except that the pyrolysis temperature in "step 3) is changed to 800℃". The other conditions remain unchanged, and the intermediate product CoP / Co2P-C composite material and the final product CoP / MoS2-C composite material are obtained.

[0045] Example 3: A method for preparing a CoP / MoS2-C hollow composite piezoelectric material. The method steps are repeated in Example 1, except that the pyrolysis temperature in "step 3) is changed to 900℃". The other conditions remain unchanged, and the intermediate product CoP / Co2P-C composite material and the final product CoP / MoS2-C composite material are obtained.

[0046] Example 4: A method for preparing a CoP / MoS2-C hollow composite piezoelectric material. The method steps are repeated in Example 1, except that the pyrolysis temperature in "step 3) is changed to 1000℃". The other conditions remain unchanged, and the intermediate product CoP / Co2P-C composite material and the final product CoP / MoS2-C composite material are obtained.

[0047] The intermediate CoP / Co2P-C composite materials obtained under different pyrolysis conditions in Examples 1-4 were named CoP / Co2P-C700, CoP / Co2P-C800, CoP / Co2P-C900, and CoP / Co2P-C1000, respectively. Their XRD patterns are summarized in […]. Figure 1 In the middle. By Figure 1 It is evident that the crystallinity of the material is not high under pyrolysis conditions of 700 ℃ and 800 ℃, while the crystallinity is higher at 900 ℃ and 1000 ℃, making it suitable as a precursor for subsequent modification.

[0048] The XRD patterns of the intermediate product CoP / Co2P-C and the final product CoP / MoS2-C obtained under the pyrolysis temperature of 900℃ in Example 3 are shown in the figure below. Figure 2a and Figure 2bAs shown, after hydrothermal treatment, CoP / Co2P-C exhibits relatively obvious diffraction peaks that match the crystal planes of MoS2, in addition to the typical diffraction peaks of CoP, indicating the coexistence of CoP and MoS2.

[0049] TEM image of the intermediate product CoP / Co2P-C obtained under pyrolysis temperature of 900℃ in Example 3 is shown below. Figure 3 As shown. By Figure 3 It can be seen that due to the pyrolysis treatment at 900℃, ZIF-67@PZS gradually transforms into hollow Co2P / CoP-C with micro-meso-macroporous characteristics. In the electron microscope image, it can be observed that the intercrystalline spacing is 0.22 nm, which matches well with the (121) plane of Co2P.

[0050] TEM image of the final product CoP / MoS2-C composite material obtained at a pyrolysis temperature of 900℃ in Example 3 is shown below. Figure 4 As shown, the EDS image is... Figure 5 .Depend on Figure 4 It is evident that the CoP / MoS2-C composite material exhibits a unique hollow hexahedral structure. Compared to MoS2, which is highly prone to aggregation, the ZIF-67 framework provides ample dispersion sites for MoS2, significantly improving its aggregation phenomenon. Furthermore, TEM characterization of the CoP / MoS2-C composite material, as shown by its EDS images, reveals that Mo and S elements are uniformly distributed on the surface of the CoP / MoS2-C composite material, while Co, P, O, C, and N are uniformly distributed within the material.

[0051] Example 5: Effect of CoP / MoS2-C catalyst on CO2 desorption by TETA-DEEA mixed phase change absorbent.

[0052] The reactor is a 250 mL three-necked flask. A thermometer is installed at the left neck to measure the real-time temperature of the amine solution. The middle neck has a 300 mm serpentine condenser, which uses cooling water to prevent amine solution loss. The condenser is connected to a soap film flow meter via a rubber hose. The right neck is sealed with a rubber stopper to ensure the airtightness of the apparatus. The temperature of the amine solution is provided by an oil bath, and magnetic stirring is used to ensure sufficient contact between the catalyst and the amine solution.

[0053] Example 5: The method for desorbing CO2 using a TETA-DEEA mixed phase change absorbent includes the following steps:

[0054] 1) The organic amine aqueous solution is a 1:3 molar ratio of TETA and DEEA, with a total amine concentration of 4M. CO2 is bubbled into 300 mL of the organic amine aqueous solution, causing liquid-liquid phase separation until the lower phase solution has a CO2 loading of 0.75 mol CO2 / mol amine solution. After CO2 absorption is complete, the upper and lower phases are separated, and the CO2-rich phase solution (the lower phase) is collected.

[0055] 2) Take 200 mL of the CO2 enriched phase solution obtained in step 1) and add it to a three-necked flask. Add 0.2 g of catalyst at a ratio of 0.1 g: 100 mL (blank control means no catalyst is added). Place the three-necked flask in an oil bath and start heating from room temperature (about 25°C). Heat the mixture to 95°C (the heating time from room temperature (about 25°C) to 95°C is about 18 min), then maintain the temperature. After heating and desorption for 120 min, stop the heating and desorption operation.

[0056] 3) During the heating and desorption process in step 2), the desorbed CO2 gas passes through the condenser and reaches the soap film flow meter. The amount of CO2 desorbed is obtained by mathematically integrating the rate-time curve using Origin plotting software. The CO2 desorption rate at different times can be calculated using the flow data measured by the soap film flow meter.

[0057] Following the method of CO2 desorption using the TETA-DEEA mixed phase change absorbent in Example 5, the experimental results under completely identical experimental conditions using different catalysts are shown in Table 1. A blank control experiment was also conducted under completely identical experimental conditions without adding a catalyst.

[0058] In the CO2 desorption experiment, the electricity consumption during heating and desorption for 120 min was measured using an electric meter. This is the heat load of the CO2 desorption experiment, expressed in kWh. The relative heat load is defined as the percentage of the total electricity consumption in the CO2 desorption experiment of each catalyst group to the total electricity consumption in the CO2 desorption experiment of the blank control group. The relative heat load of the CO2 desorption experiment of the blank control group is 100%.

[0059] The catalyst “MoS2” used in Table 1 was sourced from Shanghai Aladdin Reagent Co., Ltd.

[0060] Table 1

[0061] .

[0062] As can be seen from the experimental results in Table 1, the catalyst material of the present invention can increase the peak CO2 desorption rate by 2.98 times, the CO2 desorption capacity of the biphasic amine solution is 1.76 times that of the uncatalyzed case, and the relative heat load can be reduced by 74.58%.

[0063] In addition, following the CO2 desorption method of the TETA-DEEA mixed phase change absorbent described in Example 5, the final product CoP / MoS2-C from Example 3 was used as a catalyst for cyclic desorption experiments. The experimental process repeated steps 1)-3) of Example 5. After each desorption reaction lasting 120 min, the solid material was collected by centrifugation, dried, and directly added to the next batch of "fresh CO2-enriched phase solution" for heated desorption experiments. The change in CO2 loading in the amine solution over time at different catalyst cycle numbers is shown in [Figure number missing]. Figure 6 As shown, the highest rate of CO2 desorption within 120 min of heating is listed in... Figure 7 middle.

[0064] Example 6: Method for desorbing CO2 using TETA-DEEA mixed phase change absorbent. The experimental steps are the same as in Example 5, except that in "Step 2), heating desorption is changed from 120 min to 70 min", and the other conditions remain unchanged.

[0065] The intermediate products CoP / Co2P-C from Examples 1-4 were named CoP / Co2P-C700, CoP / Co2P-C800, CoP / Co2P-C900, and CoP / Co2P-C1000, respectively. Using CoP / Co2P-C700, CoP / Co2P-C800, CoP / Co2P-C900, and CoP / Co2P-C1000 as catalysts, and following the method for desorbing CO2 using the TETA-DEEA mixed phase change absorber described in Example 6, CO2 desorption experiments were conducted under identical experimental conditions. The relationship between the CO2 desorption rate and heating time within 70 min under different catalysts is shown in the figure. Figure 8 A control experiment was also conducted under identical experimental conditions without the addition of a catalyst. Figure 8 The orange dashed line represents the temperature of the mixture heated at different times.

[0066] Depend on Figure 8 It can be seen that the catalyst CoP / Co2P-C900 exhibits the best catalytic desorption performance. Therefore, in the preparation process of the catalyst of this invention, the preferred pyrolysis temperature is 900℃.

[0067] The contents described in this specification are merely an enumeration of the implementation forms of the inventive concept, and the scope of protection of this invention should not be regarded as limited to the specific forms described in the embodiments.

Claims

1. The application of a CoP / MoS2-C hollow composite piezoelectric material as a catalyst in the catalytic desorption of carbon dioxide, characterized in that, The preparation method of the CoP / MoS2-C hollow composite piezoelectric material includes the following steps: Step 1: Hexachlorocyclotriphosphazene, bisphenol S and ZIF-67 nanomaterials were stirred together in a solvent, and triethylamine was added. A condensation reaction was carried out under stirring. The resulting polyphosphazene PZS was coated on the surface of ZIF-67. After the reaction was completed, the product was collected by centrifugation and dried to obtain the core-shell ZIF-67@PZS composite material. Step 2: The ZIF-67@PZS composite material obtained in Step 1 is placed in a tube furnace and calcined at high temperature under a nitrogen atmosphere to obtain hollow CoP / Co2P-C material. Step 3: Disperse the CoP / Co2P-C material, S source and Mo source obtained in Step 2 in deionized water, stir evenly, transfer the mixture to a high-pressure reactor for hydrothermal reaction, and finally wash and dry to obtain CoP / MoS2-C hollow composite piezoelectric material, thus completing the preparation.

2. The application as described in claim 1, characterized in that, In step 1, the molar ratio of hexachlorocyclotriphosphazene to bisphenol S is 1:2.5-3, and the ratio of the total amount of hexachlorocyclotriphosphazene and bisphenol S to the mass of ZIF-67 is 1 mol: 80-100 g.

3. The application as described in claim 1, characterized in that, In step 1, the total amount of hexachlorocyclotriphosphazene and bisphenol S is in the ratio of the volume of triethylamine to 2-4 mmol: 1 mL; the condensation reaction in step 1 is carried out at room temperature for 10-20 h.

4. The application as described in claim 1, characterized in that, In step 1, the solvent is methanol, and the dispersion concentration of ZIF-67 nanomaterials in the solvent is 2-5 g / L.

5. The application as described in claim 1, characterized in that, In step 2, the high-temperature calcination temperature is 900-1000℃, and the calcination time is 1-4 hours.

6. The application as described in claim 1, characterized in that, In step 3, the S source is thiourea, the Mo source is ammonium molybdate, and the molar ratio of the S source to the Mo source is 8-10:1; the total amount of S source and Mo source is 1 mol: 4-8 g of the mass of the CoP / Co2P-C material.

7. The application as described in claim 1, characterized in that, In step 3, the hydrothermal reaction temperature is 180-220℃, and the reaction time is 20-30h.

8. The application as described in claim 1, characterized in that, The application method includes the following steps: S1: Pass CO2 into an aqueous solution of organic amines containing primary and tertiary amines; S2: After CO2 absorption in step S1, liquid-liquid phase separation is performed, and the CO2-enriched phase solution is collected. S3: The CoP / MoS2-C catalyst is added to the CO2-enriched phase solution, and the reaction desorbs CO2 at 90~95 °C to regenerate the organic amine; In step S1, the organic amine aqueous solution contains TETA and DEEA, the molar ratio of TETA to DEEA is 0.5~2:3, and the total amine concentration of the organic amine aqueous solution is 2~6 M; In step S2, the amount of CO2 absorbed in the organic amine aqueous solution is greater than or equal to 0.75 mol CO2 / mol amine solution; In step S3, the amount of catalyst added to the CO2 enriched phase solution is 0.5-3 mg / mL.

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