Oxygen-resistant nickel-based bifunctional material, preparation method and application thereof

Abstract

The application provides an oxygen-resistant nickel-based bifunctional material, a preparation method and application thereof. The oxygen-resistant nickel-based bifunctional material comprises an adsorption component and a catalytic component. The adsorption component comprises MgO and Al2O3, and the molar ratio between Mg and Al is (0.5-1.99):1. The catalytic component comprises NiO and Al2O3, and the molar ratio between Ni and Al is (3.01-6):1. The adsorption component and the catalytic component are prepared by using a parallel flow precipitation method respectively, and then the two are mixed to obtain the oxygen-resistant nickel-based bifunctional material. The oxygen-resistant nickel-based bifunctional material prepared in the application realizes the integration of carbon dioxide capture and conversion of oxygen-containing flue gas at a low reaction temperature (200-350 DEG C) under constant temperature conditions, greatly reduces the disposal energy consumption of carbon dioxide in the oxygen-containing flue gas, significantly improves the reaction timeliness, and realizes nearly 100% carbon dioxide capture and methane conversion rate through optimization of conditions.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of catalysts, and particularly relates to a nickel-based oxygen-tolerant bifunctional material, a preparation method and application thereof. BACKGROUND

[0002] Carbon dioxide capture-conversion integrated technology is an integrated CCUS technology developed within the framework of CCUS (carbon dioxide capture, utilization and storage). In this process, the carbon dioxide emitted by the source is captured by the absorbent or adsorbent, and then directly reacts with the co-reactant to convert into downstream products without obtaining high-concentration carbon dioxide. In this integrated process, the captured carbon dioxide does not need to go through the energy-consuming and time-consuming desorption or adsorption process, thereby greatly reducing the overall energy consumption of the CCUS whole industry chain. That is, the integration of carbon dioxide capture and conversion is a new high-efficiency and low-energy-consumption carbon dioxide emission reduction technology.

[0003] In real working condition flue gas emission sources, the presence of oxygen and water vapor has a significant impact on the performance of the bifunctional material for carbon dioxide capture-conversion integration. In particular, oxygen in the flue gas can easily oxidize the catalytic components in the bifunctional material during the capture process, which may cause a significant decrease in the catalytic activity of the bifunctional material in the subsequent conversion process. To address the impact of oxygen on the performance of the bifunctional material, domestic and foreign research teams mainly use ruthenium and other noble metals as catalytic components to achieve carbon dioxide capture and methanation under oxygen-containing flue gas conditions (Journal of CO2 Utilization, 2020, 38:262-272; Applied Catalysis B: Environmental, 2015, 168-169:370-376; Chemical Engineering Journal, 2019, 375:121953). However, noble metals are too expensive, and the bifunctional material is used for half of the time in the oxygen-containing flue gas capture process during the integration process. Therefore, the economic efficiency of avoiding the impact of oxygen by adding noble metals and the like is poor. In existing reports, non-noble metal-based catalytic components, which are inexpensive and readily available, can only be used for carbon dioxide capture and methanation of flue gas under oxygen-free conditions at a lower reaction temperature (Chemical Engineering Journal, 2017, 322:590-602; Chemical Engineering Journal, 2023, 455:140623).

[0004] Therefore, it is crucial to develop non-noble metal-based bifunctional materials that can be used under oxygen-containing flue gas conditions for the promotion of carbon dioxide capture-conversion integrated technology. SUMMARY

[0005] In view of the above-mentioned disadvantages of the prior art, the purpose of the present application is to provide an oxygen-tolerant nickel-based bifunctional material, a preparation method and applications thereof, for solving the problems of high cost and poor economy in the prior art by adding noble metals to avoid the influence of oxygen, and the problem of the inability of the non-noble metal-based catalytic components in the prior art to be used for carbon dioxide capture and conversion integration under oxygen-containing flue gas conditions at a lower temperature.

[0006] To achieve the above-mentioned purpose and other related purposes, the present application provides an oxygen-tolerant nickel-based bifunctional material, which comprises an adsorption component and a catalytic component, the adsorption component comprises MgO and Al2O3, wherein the molar ratio between Mg element and Al element in the adsorption component is (0.5-1.99):1; the catalytic component comprises NiO and Al2O3, wherein the molar ratio between Ni element and Al element in the catalytic component is (3.01-6):1.

[0007] Preferably, the corresponding molar ratio between the metal elements Mg, Ni and Al in the oxygen-tolerant nickel-based bifunctional material is (0.2-1.8):(0.3-2.5):1.

[0008] The present application also provides a preparation method of an oxygen-tolerant nickel-based bifunctional material, which comprises the following steps:

[0009] S1, according to the proportion, magnesium nitrate and aluminum nitrate are added to deionized water for stirring and dissolving to prepare a first active metal mixed aqueous solution;

[0010] S2, the first active metal mixed aqueous solution is precipitated with a first precipitant aqueous solution in parallel flow, then heated and aged for a period of time, cooled to room temperature, and then subjected to centrifugal separation, washing, drying and calcination to obtain an adsorption component;

[0011] S3, according to the proportion, nickel nitrate and aluminum nitrate are added to deionized water for stirring and dissolving to prepare a second active metal mixed aqueous solution;

[0012] S4, the second active metal mixed aqueous solution is precipitated with a second precipitant aqueous solution in parallel flow, then heated and aged for a period of time, cooled to room temperature, and then subjected to centrifugal separation, washing, drying and calcination to obtain a catalytic component;

[0013] S5, the adsorption component obtained in step S2 and the catalytic component obtained in step S4 are uniformly mixed to obtain an oxygen-tolerant nickel-based bifunctional material.

[0014] Preferably, the molar ratio between the magnesium nitrate and aluminum nitrate in step S1 is (0.5-1.99):1.

[0015] Preferably, the total concentration of metal ions in the first active metal mixed aqueous solution in step S1 is 0.2-2.0 mol / L.

[0016] Preferably, the preparation method of the first precipitant aqueous solution in step S2 is as follows: carbonates and alkaline hydroxides are added into deionized water according to the ratio, stirred and dissolved, and then diluted to prepare the first precipitant aqueous solution; the molar ratio between the carbonates and the alkaline hydroxides is (0.2-1.5):1, and the total concentration of metal ions in the prepared first precipitant aqueous solution is 2.0-6.0 mol / L.

[0017] Preferably, the temperature of the concurrent precipitation in step S2 is 10-40℃, and the pH value of the concurrent precipitation is 9-13.

[0018] Preferably, the temperature of the heating aging in step S2 is 60-95℃, and the time of the heating aging is 2-24 h.

[0019] Preferably, the temperature of the calcination in step S2 is 500-800℃, and the time of the calcination is 3-8 h.

[0020] Preferably, the carbonates in the first precipitant aqueous solution include one or a combination of sodium carbonate and potassium carbonate, and the alkaline hydroxides include one or a combination of sodium hydroxide and potassium hydroxide.

[0021] Preferably, the molar ratio between the nickel nitrate and the aluminum nitrate in step S3 is (3.01-6):1.

[0022] Preferably, the total concentration of metal ions in the second active metal mixed aqueous solution prepared in step S3 is 0.2-2.0 mol / L.

[0023] Preferably, the second precipitant aqueous solution in step S4 is a mixed aqueous solution of sodium carbonate and sodium hydroxide, and the molar ratio between the sodium carbonate and the sodium hydroxide is (0.5-1.5):1.

[0024] Preferably, the total concentration of metal ions in the second precipitant aqueous solution in step S4 is 1.5-5.0 mol / L.

[0025] Preferably, the temperature of the concurrent precipitation in step S4 is 10-40℃, and the pH value of the concurrent precipitation is 9-13.

[0026] Preferably, the temperature of the heating aging in step S4 is 60-95℃, and the time of the heating aging is 2-24 h.

[0027] Preferably, the temperature of the roasting in step S4 is 400-500 DEG C, and the time of the roasting is 4-12 h.

[0028] Preferably, the oxygen-resistant nickel-based bifunctional material obtained in step S5 comprises metal elements Mg, Ni and Al, and the corresponding molar ratio among the three is (0.2-1.8):(0.3-2.5):1.

[0029] The application further provides an application of the oxygen-resistant nickel-based bifunctional material prepared by the preparation method of the oxygen-resistant nickel-based bifunctional material, and an application of the oxygen-resistant nickel-based bifunctional material in oxygen-containing flue gas carbon dioxide capture and conversion integration, wherein the oxygen-containing flue gas carbon dioxide capture and conversion integration process is carried out under constant temperature conditions of 200-350 DEG C.

[0030] As described above, the oxygen-resistant nickel-based bifunctional material, the preparation method and the application thereof have the following beneficial effects:

[0031] The oxygen-resistant nickel-based bifunctional material in the application comprises an adsorption component and a catalytic component, by regulating the molar ratio of Mg to Al in the adsorption component, the molar ratio of Ni to Al in the catalytic component, and the matching relationship between the adsorption component and the catalytic component, a cheap and easily obtained nickel-based bifunctional material is obtained, effectively solving the problem of high cost and poor economy in the prior art by adding noble metals to avoid the influence of oxygen, and realizing carbon dioxide capture and in-situ conversion under real working condition oxygen-containing flue gas conditions.

[0032] The oxygen-resistant nickel-based bifunctional material prepared in the application realizes oxygen-containing flue gas carbon dioxide capture and conversion integration under constant temperature conditions at a relatively low reaction temperature (200-350 DEG C), greatly reduces the disposal energy consumption of oxygen-containing flue gas carbon dioxide, significantly improves the reaction timeliness, realizes nearly 100% carbon dioxide capture and methane conversion rate through optimized conditions, and is of great importance to the popularization of the non-noble metal bifunctional material for oxygen-containing flue gas conditions to oxygen-containing flue gas carbon dioxide capture and conversion integration preparation of methane technology. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 The XRD patterns of the adsorption component, the catalytic component and the finally prepared oxygen-resistant nickel-based bifunctional material in the oxygen-resistant nickel-based bifunctional material prepared in Example 1 of the application are shown.

[0034] Figure 2 The TEM image of the adsorption component in the oxygen-resistant nickel-based bifunctional material prepared in Example 1 of the application is shown.

[0035] Figure 3 The TEM image of the catalytic component in the oxygen-resistant nickel-based bifunctional material prepared in Example 1 of the application is shown. DETAILED DESCRIPTION

[0036] Other advantages and novel features of the present application will become apparent from the following detailed description when taken in conjunction with the announcements thereof. The application can also be put into practice in various different ways and embodiments, and various modifications and changes thereto can be made without departing from its spirit.

[0037] The present application provides a kind of oxygen-resistant nickel-based bifunctional material, which includes adsorption component and catalytic component, adsorption component includes MgO and Al2O3, wherein, in adsorption component, the molar ratio between Mg element and Al element is (0.5-1.99):1;Catalytic component includes NiO and Al2O3, wherein, in catalytic component, the molar ratio between Ni element and Al element is (3.01-6):1.

[0038] Specifically, the molar ratio between Mg element and Al element in adsorption component can include any value within the range of 0.5:1, 0.75:1, 1:1, 1.25:1, 1.5:1, 1.75:1, 1.99:1, etc., which can be adjusted according to actual conditions;The molar ratio between Ni element and Al element in catalytic component can include any value within the range of 3.01:1, 4:1, 5:1, 6:1, etc., which can be adjusted according to actual conditions. The molar ratio between Ni element and Al element directly affects the oxygen resistance performance of the oxygen-resistant nickel-based bifunctional material. If the molar ratio between them is too low, the oxygen resistance performance of the nickel-based bifunctional material will be poor. If the molar ratio between them is too high, it may not be possible to form the desired material structure, resulting in poor overall performance of the formed material. In addition, too high Ni content will significantly increase the cost of the prepared nickel-based bifunctional material.

[0039] As an example, the corresponding molar ratio between the metal elements Mg, Ni and Al in the oxygen-resistant nickel-based bifunctional material is (0.2-1.8):(0.3-2.5):1.

[0040] Specifically, the corresponding molar ratio between the metal elements Mg, Ni and Al in the oxygen-resistant nickel-based bifunctional material can include any value within the range of 0.2:2.5:1, 0.2:0.3:1, 0.42:1:1, 0.83:0.67:1, 1.14:1.43:1, 1.8:0.3:1, 1.8:2.5:1, etc., which can be adjusted according to actual conditions.

[0041] The present application also provides a preparation method of an oxygen-resistant nickel-based bifunctional material, which includes the following steps:

[0042] S1, according to the proportion, magnesium nitrate and aluminum nitrate are added into deionized water to be stirred and dissolved, and a first active metal mixed aqueous solution is prepared;

[0043] S2, the first active metal mixed aqueous solution is precipitated with the first precipitant aqueous solution in parallel flow, then heated and aged for a period of time, cooled to room temperature, and then centrifuged, washed, dried, and calcined to obtain an adsorption component;

[0044] S3, according to the proportion, nickel nitrate and aluminum nitrate are added into deionized water to be stirred and dissolved, and a second active metal mixed aqueous solution is prepared;

[0045] S4, the second active metal mixed aqueous solution is precipitated with the second precipitant aqueous solution in parallel flow, then heated and aged for a period of time, cooled to room temperature, and then centrifuged, washed, dried, and calcined to obtain a catalytic component;

[0046] S5, the adsorption component obtained in step S2 and the catalytic component obtained in step S4 are uniformly mixed to obtain a nickel-based oxygen-resistant bifunctional material.

[0047] Specifically, the bifunctional material is prepared by preparing an adsorption component and a catalytic component respectively, and then mixing the two components; compared with the one-step precipitation method commonly used in the prior art, the preparation method of the present application can increase the content of nickel in the catalytic component in a local range, reduce the interaction between nickel and Al2O3, enhance the activity of nickel, and improve the oxygen resistance of the bifunctional material.

[0048] As an example, the molar ratio between magnesium nitrate and aluminum nitrate in step S1 is (0.5-1.99):1.

[0049] Specifically, the molar ratio between magnesium nitrate and aluminum nitrate in step S1 can include any value within the range of 0.5:1, 0.75:1, 1:1, 1.25:1, 1.5:1, 1.75:1, 1.99:1, etc., which can be adjusted according to actual conditions.

[0050] As an example, the total concentration of metal ions in the first active metal mixed aqueous solution in step S1 is 0.2-2.0 mol / L.

[0051] Specifically, the total concentration of metal ions in the first active metal mixed aqueous solution in step S1 can include any value within the range of 0.2 mol / L, 0.5 mol / L, 1.0 mol / L, 1.5 mol / L, 1.8 mol / L, 2.0 mol / L, etc., which can be adjusted according to actual conditions; too low total concentration of metal ions will affect the preparation efficiency of the adsorption component, and too high total concentration of metal ions will cause uneven dispersion during parallel precipitation.

[0052] As an example, the preparation method of the first precipitant aqueous solution in step S2 is specifically as follows: according to the ratio, carbonates and alkaline hydroxide are added to deionized water for stirring and dissolving, and then diluted to prepare the first precipitant aqueous solution; wherein the molar ratio between the carbonates and the alkaline hydroxide is (0.2-1.5):1, and the total concentration of metal ions in the prepared first precipitant aqueous solution is 2.0-6.0 mol / L.

[0053] Specifically, the molar ratio between the carbonates and the alkaline hydroxide in the first precipitant aqueous solution can include any value within the range of 0.2:1, 0.5:1, 0.8:1, 1:1, 1.2:1, 1.5:1, etc., which can be adjusted according to actual conditions; the total concentration of metal ions in the prepared first precipitant aqueous solution can include any value within the range of 2.0 mol / L, 3.0 mol / L, 4.0 mol / L, 5.0 mol / L, 6.0 mol / L, etc., which can be adjusted according to actual conditions. The total concentration of metal ions in the first precipitant aqueous solution is adjusted according to dilution, and deionized water is used for dilution.

[0054] As an example, the carbonates include one or a combination of sodium carbonate and potassium carbonate, and the alkaline hydroxide includes one or a combination of sodium hydroxide and potassium hydroxide.

[0055] As an example, the temperature of the parallel flow precipitation in step S2 is 10-40℃, and the pH value of the parallel flow precipitation is 9-13.

[0056] Specifically, the first active metal mixed aqueous solution and the first precipitant aqueous solution are precipitated in parallel flow, specifically, the first active metal mixed aqueous solution and the first precipitant aqueous solution are added to the stirred reactor in parallel flow at a certain speed to generate a precipitate mixture; the temperature of the parallel flow precipitation refers to the temperature in the reactor, which can include any value within the range of 10℃, 15℃, 20℃, 25℃, 30℃, 35℃, 40℃, etc., which can be adjusted according to actual conditions; the pH value of the parallel flow precipitation refers to the pH value during the parallel flow precipitation, which can include any value within the range of 9, 10, 11, 12, 13, etc., which can be adjusted by controlling the flow rate of the first active metal mixed aqueous solution and the first precipitant aqueous solution.

[0057] As an example, the temperature of the heating aging in step S2 is 60-95℃, and the time of the heating aging is 2-24h.

[0058] Specifically, the temperature of the heating aging in step S2 can include any value within the range of 60℃, 65℃, 70℃, 75℃, 80℃, 85℃, 90℃, 95℃, etc., which can be adjusted according to actual conditions; the time of the heating aging can include any value within the range of 2h, 6h, 12h, 18h, 24h, etc., which can be adjusted according to actual conditions.

[0059] As an example, the temperature of the calcination in step S2 is 500-800°C, and the time of the calcination is 3-8h.

[0060] Specifically, the temperature of the calcination in step S2 can include any value within the range of 500°C, 550°C, 600°C, 650°C, 700°C, 750°C, 800°C, etc., and can be adjusted according to actual conditions; the time of the calcination can include any value within the range of 3h, 4h, 5h, 6h, 7h, 8h, etc., and can be adjusted according to actual conditions.

[0061] As an example, the molar ratio between the nickel nitrate and the aluminum nitrate in step S3 is (3.01-6):1.

[0062] Specifically, the molar ratio between the nickel nitrate and the aluminum nitrate in step S3 can include any value within the range of 3.01:1, 4:1, 5:1, 6:1, etc., and can be adjusted according to actual conditions.

[0063] As an example, the total concentration of metal ions in the second active metal mixed aqueous solution prepared in step S3 is 0.2-2.0mol / L.

[0064] Specifically, the total concentration of metal ions in the second active metal mixed aqueous solution prepared in step S3 can include any value within the range of 0.2mol / L, 0.5mol / L, 1.0mol / L, 1.5mol / L, 1.8mol / L, 2.0mol / L, etc., and can be adjusted according to actual conditions.

[0065] As an example, the second precipitant aqueous solution in step S4 is a mixed aqueous solution of sodium carbonate and sodium hydroxide, and the molar ratio between the sodium carbonate and the sodium hydroxide is (0.5-1.5):1.

[0066] Specifically, the molar ratio between the sodium carbonate and the sodium hydroxide in the second precipitant aqueous solution in step S4 can include any value within the range of 0.5:1, 0.8:1, 1:1, 1.2:1, 1.5:1, etc., and can be adjusted according to actual conditions.

[0067] As an example, the total concentration of metal ions in the second precipitant aqueous solution in step S4 is 1.5-5.0mol / L.

[0068] Specifically, the total concentration of metal ions in the second precipitant aqueous solution in step S4 can include any value within the range of 1.5mol / L, 2mol / L, 3mol / L, 4mol / L, 4.5mol / L, 5mol / L, etc., and can be adjusted according to actual conditions.

[0069] As an example, the temperature of the parallel flow precipitation in step S4 is 10-40 DEG C, and the pH value of the parallel flow precipitation is 9-13.

[0070] Specifically, the temperature of the parallel flow precipitation in step S4 can include any value within the range of 10 DEG C, 15 DEG C, 20 DEG C, 25 DEG C, 30 DEG C, 35 DEG C, 40 DEG C, etc., and can be adjusted according to actual conditions; and the pH value of the parallel flow precipitation can include any value within the range of 9, 10, 11, 12, 13, etc., and can be adjusted according to actual conditions.

[0071] As an example, the temperature of the heat aging in step S4 is 60-95 DEG C, and the time of the heat aging is 2-24 h.

[0072] Specifically, the temperature of the heat aging in step S4 can include any value within the range of 60 DEG C, 65 DEG C, 70 DEG C, 75 DEG C, 80 DEG C, 85 DEG C, 90 DEG C, 95 DEG C, etc., and can be adjusted according to actual conditions; and the time of the heat aging can include any value within the range of 2 h, 6 h, 12 h, 18 h, 24 h, etc., and can be adjusted according to actual conditions.

[0073] As an example, the temperature of the calcination in step S4 is 400-500 DEG C, and the time of the calcination is 4-12 h.

[0074] Specifically, the temperature of the calcination in step S4 can include any value within the range of 400 DEG C, 420 DEG C, 440 DEG C, 450 DEG C, 460 DEG C, 480 DEG C, 500 DEG C, etc., and can be adjusted according to actual conditions; and the time of the calcination can include any value within the range of 4 h, 6 h, 8 h, 10 h, 12 h, etc., and can be adjusted according to actual conditions.

[0075] As an example, the oxygen-resistant nickel-based bifunctional material obtained in step S5 includes metal elements Mg, Ni and Al, and the corresponding molar ratio among the three is (0.2-1.8):(0.3-2.5):1.

[0076] Specifically, the corresponding molar ratio among the metal elements Mg, Ni and Al in the oxygen-resistant nickel-based bifunctional material can include any value within the range of 0.2:2.5:1, 0.2:0.3:1, 0.42:1:1, 0.83:0.67:1, 1.14:1.43:1, 1.8:0.3:1, 1.8:2.5:1, etc., and can be adjusted according to actual conditions.

[0077] The application further provides an application of the oxygen-resistant nickel-based bifunctional material prepared by the preparation method of the oxygen-resistant nickel-based bifunctional material, and an application of the oxygen-resistant nickel-based bifunctional material in oxygen-containing flue gas carbon dioxide capture and conversion integration, wherein the oxygen-containing flue gas carbon dioxide capture and conversion integration process is carried out under constant temperature conditions of 200-350 DEG C.

[0078] Specifically, the oxygen-containing flue gas carbon dioxide capture and conversion integrated process is carried out under constant temperature conditions, which can be carried out in any range of 200℃, 250℃, 300℃, 350℃, etc.; after the non-noble metal nickel is oxidized in the oxygen-containing flue gas capture, it can still be reduced to the catalytic component metal nickel at a higher temperature, but the energy consumption will increase as the temperature increases, and other by-products (such as carbon monoxide, etc.) may also appear. It is understood in the prior art that the temperature for the oxygen-containing flue gas carbon dioxide capture and conversion integrated process of the nickel-based bifunctional material is generally 400-600℃, while the oxygen-resistant nickel-based bifunctional material prepared in the present application can carry out the oxygen-containing flue gas carbon dioxide capture and conversion integrated process at a lower temperature (200-350℃).

[0079] In order to better understand the oxygen-resistant nickel-based bifunctional material, the preparation method and the application thereof in the present application, the oxygen-resistant nickel-based bifunctional material, the preparation method and the application thereof in the present application are described below with reference to specific examples, and it should be noted that these examples are merely descriptive and do not limit the present application in any way.

[0080] Example 1

[0081] The present embodiment provides an oxygen-resistant nickel-based bifunctional material, which comprises an adsorption component and a catalytic component. The adsorption component comprises MgO and Al2O3, wherein the molar ratio between Mg element and Al element is 1:1. The catalytic component comprises NiO and Al2O3, wherein the molar ratio between Ni element and Al element in the catalytic component is 4:1. The corresponding molar ratio between the metal elements Mg, Ni and Al in the oxygen-resistant nickel-based bifunctional material is 0.83:0.67:1.

[0082] The present embodiment also provides a preparation method of the oxygen-resistant nickel-based bifunctional material, which comprises the following steps:

[0083] S1, 0.05 mol of magnesium nitrate and 0.05 mol of aluminum nitrate are weighed and added to deionized water for stirring and dissolution, and then diluted to 250 mL to prepare a first active metal mixed aqueous solution (the molar ratio between Mg element and Al element is 1:1, and the total concentration of metal ions in the active metal mixed aqueous solution is 0.4 mol / L);

[0084] S2, 0.25 mol of sodium hydroxide and 0.25 mol of sodium carbonate are weighed into deionized water, stirred and dissolved, and then diluted to 250 mL to prepare a first precipitant aqueous solution (total metal ion concentration is 3 mol / L); then the first active metal mixed aqueous solution is precipitated with the first precipitant aqueous solution in parallel flow, the temperature is 25℃, the pH value is controlled at 11±0.1, stirring for 1h, then the temperature is raised to 80℃ for aging for 16h, the precipitate is separated from the solution under high-speed centrifugation, then the precipitate is washed with deionized water, repeated for 6 times, then dried at 100℃ for 12h, and then calcined at 500℃ for 6h in air atmosphere to obtain an adsorption component;

[0085] S3, 0.04 mol of nickel nitrate and 0.01 mol of aluminum nitrate are weighed into deionized water, stirred and dissolved, and then diluted to 100 mL to prepare a second active metal mixed aqueous solution (molar ratio between Ni element and Al element is 4:1, and the total metal ion concentration in the active metal mixed aqueous solution is 0.5 mol / L);

[0086] S4, 0.11 mol of sodium hydroxide and 0.11 mol of sodium carbonate are weighed into deionized water, stirred and dissolved, and then diluted to 100 mL to prepare a second precipitant aqueous solution (total metal ion concentration is 3.3 mol / L); then the second active metal mixed aqueous solution is precipitated with the second precipitant aqueous solution in parallel flow, the temperature is 25℃, the pH value is controlled at 11±0.1, stirring for 1h, then the temperature is raised to 80℃ for aging for 16h, the precipitate is separated from the solution under high-speed centrifugation, then the precipitate is washed with deionized water, repeated for 6 times, then dried at 100℃ for 12h, and then calcined at 500℃ for 6h in air atmosphere to obtain a catalytic component;

[0087] S5, the adsorption component and the catalytic component are uniformly mixed to obtain an oxygen-resistant nickel-based bifunctional material; wherein the molar ratio among Mg, Ni and Al is 0.83:0.67:1.

[0088] Referring to Figure 1 The XRD patterns of the adsorption component, the catalytic component and the finally prepared oxygen-resistant nickel-based bifunctional material in this embodiment are shown in the figure. As can be seen from the figure, the adsorption component contains a strong MgO signal, and the catalytic component contains a strong NiO signal. Since the Al2O3 signal intensity is weak, no obvious Al2O3 signal is observed in the adsorption component and the catalytic component. After mixing the adsorption component and the catalytic component, the XRD signal of the oxygen-resistant nickel-based bifunctional material is basically obtained by superposition of the adsorption component and the catalytic component.

[0089] Referring to Figure 2 , Figure 3 The TEM images of the adsorption component and the catalytic component are shown in the figure. As can be seen from the figure, the adsorption component and the catalytic component both have a good two-dimensional nanosheet structure.

[0090] Embodiment 2

[0091] The embodiment provides an oxygen-tolerant nickel-based bifunctional material, which comprises an adsorption component and a catalytic component, the adsorption component comprises MgO and Al2O3, wherein the molar ratio between Mg element and Al element is 0.5:1; the catalytic component comprises NiO and Al2O3, wherein the molar ratio between Ni element and Al element in the catalytic component is 6:1; and the corresponding molar ratio between metal elements Mg, Ni and Al in the oxygen-tolerant nickel-based bifunctional material is 0.42:1:1.

[0092] The embodiment also provides a preparation method of the oxygen-tolerant nickel-based bifunctional material, which comprises the following steps:

[0093] S1, 0.025 mol of magnesium nitrate and 0.05 mol of aluminum nitrate are weighed and added into deionized water for stirring and dissolving, and then diluted to 250 mL to prepare a first active metal mixed aqueous solution (the molar ratio between Mg element and Al element is 0.5:1, and the total concentration of metal ions in the active metal mixed aqueous solution is 0.3 mol / L);

[0094] S2, 0.2 mol of sodium hydroxide and 0.15 mol of sodium carbonate are weighed and added into deionized water for stirring and dissolving, and then diluted to 250 mL to prepare a first precipitant aqueous solution (the total concentration of metal ions is 2 mol / L); then the first active metal mixed aqueous solution and the first precipitant aqueous solution are precipitated in parallel flow, the temperature is 40 DEG C, the pH value is controlled to be 10+ / -0.1, and stirring is performed for 1 h; then the temperature is increased to 70 DEG C for aging for 20 h; the precipitate is separated from the solution under high-speed centrifugation; then the precipitate is washed with deionized water, and the washing is repeated for 6 times; then the precipitate is dried at 100 DEG C for 12 h; then the precipitate is calcined at 700 DEG C in an air atmosphere for 4 h to obtain the adsorption component;

[0095] S3, 0.06 mol of nickel nitrate and 0.01 mol of aluminum nitrate are weighed and added into deionized water for stirring and dissolving, and then diluted to 250 mL to prepare a second active metal mixed aqueous solution (the molar ratio between Ni element and Al element is 6:1, and the total concentration of metal ions in the active metal mixed aqueous solution is 0.28 mol / L);

[0096] S4, weigh 0.15 mol of sodium hydroxide and 0.225 mol of sodium carbonate into deionized water, stir and dissolve, then dilute to 250 mL to prepare a second precipitant aqueous solution (total metal ion concentration is 2.4 mol / L); then the second active metal mixed aqueous solution and the second precipitant aqueous solution are precipitated in parallel flow, the temperature is 25℃, the pH value is controlled at 10±0.1, stirring for 1h, then the temperature is raised to 70℃ for 20h, the precipitate is separated from the solution under high speed centrifugation, then the precipitate is washed with deionized water, repeated for 6 times, then dried at 100℃ for 12h, then calcined at 450℃ for 8h in air atmosphere, to obtain a catalytic component;

[0097] S5, uniformly mix the adsorption component and the catalytic component to obtain an oxygen-resistant nickel-based bifunctional material; wherein the molar ratio between Mg, Ni and Al is 0.42:1:1.

[0098] Example 3

[0099] The embodiment provides an oxygen-resistant nickel-based bifunctional material, which comprises an adsorption component and a catalytic component, the adsorption component comprises MgO and Al2O3, wherein the molar ratio between Mg element and Al element is 1:1; the catalytic component comprises NiO and Al2O3, wherein the molar ratio between Ni element and Al element in the catalytic component is 4:1; and the corresponding molar ratio between metal elements Mg, Ni and Al in the oxygen-resistant nickel-based bifunctional material is 0.83:0.67:1.

[0100] The embodiment also provides a preparation method of an oxygen-resistant nickel-based bifunctional material, which comprises the following steps:

[0101] S1, weigh 0.05 mol of magnesium nitrate and 0.05 mol of aluminum nitrate into deionized water, stir and dissolve, then dilute to 100 mL to prepare a first active metal mixed aqueous solution (the molar ratio between Mg element and Al element is 1:1, and the total metal ion concentration in the active metal mixed aqueous solution is 1 mol / L);

[0102] S2, weigh 0.25 mol of potassium hydroxide and 0.125 mol of potassium carbonate into deionized water, stir and dissolve, then dilute to 100 mL to prepare a first precipitant aqueous solution (the total metal ion concentration is 5 mol / L); then the first active metal mixed aqueous solution and the first precipitant aqueous solution are precipitated in parallel flow, the temperature is 40℃, the pH value is controlled at 10±0.1, stirring for 1h, then the temperature is raised to 80℃ for 16h, the precipitate is separated from the solution under high speed centrifugation, then the precipitate is washed with deionized water, repeated for 6 times, then dried at 100℃ for 12h, then calcined at 500℃ for 6h in air atmosphere, to obtain an adsorption component;

[0103] S3, 0.04 mol of nickel nitrate and 0.01 mol of aluminum nitrate are weighed and added into deionized water to be stirred and dissolved, and then diluted to 250 mL to prepare a second active metal mixed aqueous solution (the molar ratio between Ni element and Al element is 4:1, and the total concentration of metal ions in the active metal mixed aqueous solution is 0.2 mol / L);

[0104] S4, 0.11 mol of sodium hydroxide and 0.165 mol of sodium carbonate are weighed and added into deionized water to be stirred and dissolved, and then diluted to 250 mL to prepare a second precipitant aqueous solution (the total concentration of metal ions is 1.76 mol / L); Then the second active metal mixed aqueous solution and the second precipitant aqueous solution are precipitated in parallel flow, the temperature is 40℃, the pH value is controlled to be 10±0.1, stirring for 1h, then the temperature is raised to 80℃ for aging for 16h, the precipitate is separated from the solution under high-speed centrifugation, then the precipitate is washed with deionized water, repeated for 6 times, then dried at 100℃ for 12h, and then calcined at 400℃ in air atmosphere for 6h to obtain a catalytic component;

[0105] S5, the adsorption component and the catalytic component are uniformly mixed to obtain an oxygen-resistant nickel-based bifunctional material; wherein the molar ratio among Mg, Ni and Al is 0.83:0.67:1.

[0106] Example 4

[0107] The embodiment provides an oxygen-resistant nickel-based bifunctional material, which comprises an adsorption component and a catalytic component, the adsorption component comprises MgO and Al2O3, wherein the molar ratio between Mg element and Al element is 1.6:1; the catalytic component comprises NiO and Al2O3, wherein the molar ratio between Ni element and Al element in the catalytic component is 5:1; and the corresponding molar ratio among metal elements Mg, Ni and Al in the oxygen-resistant nickel-based bifunctional material is 1.14:1.43:1.

[0108] The embodiment also provides a preparation method of an oxygen-resistant nickel-based bifunctional material, which comprises the following steps:

[0109] S1, 0.08 mol of magnesium nitrate and 0.05 mol of aluminum nitrate are weighed and added into deionized water to be stirred and dissolved, and then diluted to 250 mL to prepare a first active metal mixed aqueous solution (the molar ratio between Mg element and Al element is 1.6:1, and the total concentration of metal ions in the active metal mixed aqueous solution is 0.52 mol / L);

[0110] S2, 0.31 mol of sodium hydroxide and 0.31 mol of sodium carbonate were weighed into deionized water, stirred and dissolved, and then diluted to 250 mL to prepare a first precipitant aqueous solution (total metal ion concentration of 3.72 mol / L); then the first active metal mixed aqueous solution was precipitated with the first precipitant aqueous solution in parallel flow, the temperature was 25℃, the pH value was controlled at 11±0.1, stirring for 1h, then the temperature was raised to 80℃ for aging for 16h, the precipitate was separated from the solution under high-speed centrifugation, then the precipitate was washed with deionized water, repeated washing 6 times, then dried at 100℃ for 12h, and then calcined at 500℃ in air atmosphere for 6h to obtain an adsorption component;

[0111] S3, 0.1 mol of nickel nitrate and 0.02 mol of aluminum nitrate were weighed into deionized water, stirred and dissolved, and then diluted to 100 mL to prepare a second active metal mixed aqueous solution (molar ratio between Ni element and Al element of 5:1, total metal ion concentration in the active metal mixed aqueous solution of 0.12 mol / L);

[0112] S4, 0.26 mol of sodium hydroxide and 0.13 mol of sodium carbonate were weighed into deionized water, stirred and dissolved, and then diluted to 250 mL to prepare a second precipitant aqueous solution (total metal ion concentration of 2.08 mol / L); then the second active metal mixed aqueous solution was precipitated with the second precipitant aqueous solution in parallel flow, the temperature was 25℃, the pH value was controlled at 11±0.1, stirring for 1h, then the temperature was raised to 80℃ for aging for 16h, the precipitate was separated from the solution under high-speed centrifugation, then the precipitate was washed with deionized water, repeated washing 6 times, then dried at 100℃ for 12h, and then calcined at 500℃ in air atmosphere for 6h to obtain a catalytic component;

[0113] S5, the adsorption component and the catalytic component were uniformly mixed to obtain an oxygen-resistant nickel-based bifunctional material; wherein the molar ratio between Mg, Ni and Al in the oxygen-resistant nickel-based bifunctional material was 1.14:1.43:1.

[0114] Comparative Example 1

[0115] This comparative example provides a nickel-based bifunctional material, which is different from the nickel-based bifunctional material in Example 1 in that: the adsorption component in the nickel-based bifunctional material in this comparative example includes MgO and Al2O3, wherein the molar ratio between Mg element and Al element is 1.25:1; the catalytic component includes NiO and Al2O3, wherein the molar ratio between Ni element and Al element in the catalytic component is 2:1; and the corresponding molar ratio between the metal elements Mg, Ni and Al in the oxygen-resistant nickel-based bifunctional material is 0.83:0.67:1, which is the same as in Example 1.

[0116] The comparative example also provides a preparation method of the nickel-based bifunctional material, which is different from that in the embodiment 1 in that: in the step S1, 0.05 mol of magnesium nitrate and 0.04 mol of aluminum nitrate are weighed and added into deionized water for stirring and dissolving, and then diluted to 250 mL to prepare a first active metal mixed aqueous solution (the molar ratio between the Mg element and the Al element is 1.25:1, and the total concentration of metal ions in the active metal mixed aqueous solution is 0.36 mol / L); in the step S2, 0.22 mol of sodium hydroxide and 0.22 mol of sodium carbonate are weighed and added into deionized water for stirring and dissolving, and then diluted to 250 mL to prepare a first precipitant aqueous solution (the total concentration of metal ions is 2.64 mol / L); in the step S3, 0.04 mol of nickel nitrate and 0.02 mol of aluminum nitrate are weighed and added into deionized water for stirring and dissolving, and then diluted to 100 mL to prepare a second active metal mixed aqueous solution (the molar ratio between the Ni element and the Al element is 2:1, and the total concentration of metal ions in the active metal mixed aqueous solution is 0.6 mol / L); in the step S4, 0.14 mol of sodium hydroxide and 0.14 mol of sodium carbonate are weighed and added into deionized water for stirring and dissolving, and then diluted to 100 mL to prepare a second precipitant aqueous solution (the total concentration of metal ions is 4.2 mol / L); other steps and reaction conditions are the same as those in the embodiment 1, and details are not described herein again.

[0117] Comparative example 2

[0118] The comparative example provides a nickel-based bifunctional material, and a corresponding molar ratio between metal elements Mg, Ni and Al in the nickel-based bifunctional material is 0.83:0.67:1.

[0119] The comparative example provides a preparation method of a nickel-based bifunctional material, which is different from that in the embodiment 1 in that: the comparative example uses a one-step coprecipitation method to prepare the nickel-based bifunctional material, and specifically includes the following steps:

[0120] A1, 0.05 mol of magnesium nitrate, 0.04 mol of nickel nitrate and 0.06 mol of aluminum nitrate are weighed and added into deionized water for stirring and dissolving, and then diluted to 350 mL to prepare an active metal mixed aqueous solution (in which, the molar ratio between the Mg element, the Ni element and the Al element is 0.83:0.67:1, and the total concentration of metal ions in the active metal mixed aqueous solution is 0.43 mol / L);

[0121] A2, 0.36 mol of sodium hydroxide and 0.36 mol of sodium carbonate are weighed and added into deionized water for stirring and dissolving, and then diluted to 350 mL to prepare a precipitant aqueous solution (the total concentration of metal ions is 3.08 mol / L);

[0122] A3, the active metal mixed aqueous solution and the precipitant aqueous solution are co-precipitated in parallel flow, the temperature is 25℃, the pH value is controlled to be 10±0.1, stirring is performed for 1h, then the temperature is raised to 80℃ for aging for 16h, after cooling to room temperature, the precipitate is separated from the solution under high-speed centrifugation, then the precipitate is washed with deionized water, the washing is repeated for 6 times, then drying is performed at 100℃ for 12h, then calcination is performed at 500℃ in an air atmosphere for 6h, to obtain the nickel-based bifunctional material.

[0123] Application Example 1

[0124] The application example provides an application of the nickel-based bifunctional material in oxygen-containing flue gas carbon dioxide capture and conversion integration, and specifically includes the following steps:

[0125] B1, the nickel-based bifunctional material prepared in Examples 1-4 and Comparative Examples 1-2 is ground and granulated to prepare 20-40 mesh bifunctional material particles, then the bifunctional material particles are filled in a fixed bed reactor, and the upper and lower empty volumes are filled with quartz;

[0126] B2, the bifunctional material particles filled in the fixed bed reactor are heated to 500℃ at a heating rate of 10℃ / min under a hydrogen atmosphere with a flow rate of 50mL / min, and reduced for 2h, then cooled to 300℃ under a hydrogen atmosphere;

[0127] B3, after the temperature of the fixed bed reactor is stabilized, the feed gas is switched to 15vol.%CO2 / 5vol.%O2 / 80vol.%N2, adsorbed for 3min, then switched to hydrogen reaction, with 6min as a cycle period, and operated for 240min.

[0128] The tail gas of the fixed bed reactor in the application example is analyzed for gas composition, and the CO2 capture rate and methane conversion rate in the entire oxygen-containing flue gas carbon dioxide capture and conversion integration process are calculated, and the results are as shown in Table 1.

[0129] Table 1, analysis results of the application of the nickel-based bifunctional material prepared in Examples 1-4 and Comparative Examples 1-2 in oxygen-containing flue gas carbon dioxide capture and conversion integration

[0130]

[0131] The results in Table 1 show that the nickel-based bifunctional materials in Examples 1-4 have high carbon dioxide capture rate and methane conversion rate in the carbon dioxide capture and conversion integrated process of oxygen-containing flue gas, but the carbon dioxide capture rate and methane conversion rate of Comparative Examples 1-2 decrease significantly under the condition that the molar ratio of metal elements Mg, Ni and Al is the same as that of Example 1. The corresponding molar ratio of metal elements Mg, Ni and Al in Comparative Examples 1-2 and Example 1 is 0.83:0.67:1, and the difference is that the molar ratio of Ni element to Al element in the catalytic component of Comparative Example 1 is 2:1, and Comparative Example 2 adopts a one-step coprecipitation method, which is quite different from the preparation method of the present application.

[0132] In summary, the oxygen-tolerant nickel-based bifunctional material in the present application includes an adsorption component and a catalytic component. By adjusting the molar ratio of Mg to Al in the adsorption component, the molar ratio of Ni to Al in the catalytic component, and the ratio of the adsorption component to the catalytic component, a cheap and easily obtained nickel-based bifunctional material is obtained, which effectively solves the problem of high cost and poor economy in the prior art by adding noble metals to avoid the influence of oxygen, and realizes the capture and in-situ conversion of carbon dioxide under real working conditions of oxygen-containing flue gas. The oxygen-tolerant nickel-based bifunctional material prepared in the present application realizes the integration of carbon dioxide capture and conversion of oxygen-containing flue gas at a low reaction temperature (200-350℃) under constant temperature conditions, greatly reduces the disposal energy consumption of carbon dioxide in oxygen-containing flue gas, significantly improves the reaction efficiency, and realizes nearly 100% carbon dioxide capture and methane conversion rate by optimizing the conditions. The development of non-noble metal bifunctional materials for oxygen-containing flue gas is of great importance to the popularization of the technology of preparing methane by integrating carbon dioxide capture and conversion of oxygen-containing flue gas. Therefore, the present application effectively overcomes the shortcomings of the prior art and has high industrial utilization value.

[0133] The above examples are only illustrative of the principles and effects of the present application, and are not intended to limit the present application. Any person skilled in the art can modify or change the above examples without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical thought disclosed by the present application should be covered by the claims of the present application.

Claims

1. A method for preparing an oxygen-tolerant nickel-based bifunctional material for the integrated production of methane from oxygen-containing flue gas carbon dioxide capture, characterized by: The preparation method comprises the following steps: S1, according to the proportion, magnesium nitrate and aluminum nitrate are added to deionized water to stir and dissolve, and a first active metal mixed aqueous solution is prepared; the molar ratio between the magnesium nitrate and the aluminum nitrate is (0.5-1.99):1; S2, the first active metal mixed aqueous solution is precipitated with a first precipitant aqueous solution in parallel flow, then heated and aged for a period of time, cooled to room temperature, and then centrifuged, washed, dried, and calcined to obtain an adsorption component; S3, according to the proportion, nickel nitrate and aluminum nitrate are added to deionized water to stir and dissolve, and a second active metal mixed aqueous solution is prepared; the molar ratio between the nickel nitrate and the aluminum nitrate is (3.01-6):1; S4, the second active metal mixed aqueous solution is precipitated with a second precipitant aqueous solution in parallel flow, then heated and aged for a period of time, cooled to room temperature, and then centrifuged, washed, dried, and calcined to obtain a catalytic component; S5, the adsorption component obtained in step S2 and the catalytic component obtained in step S4 are uniformly mixed to obtain a nickel-based oxygen-resistant bifunctional material; The obtained nickel-based oxygen-resistant bifunctional material comprises an adsorption component and a catalytic component, the adsorption component comprises MgO and Al2O3, wherein the molar ratio between Mg and Al in the adsorption component is (0.5-1.99):1; the catalytic component comprises NiO and Al2O3, wherein the molar ratio between Ni and Al in the catalytic component is (3.01-6):1; the corresponding molar ratio between the metal elements Mg, Ni and Al in the nickel-based oxygen-resistant bifunctional material is (0.2-1.8):(0.3-2.5):

1.

2. The method of claim 1, wherein the method is characterized by: The total concentration of metal ions in the first active metal mixed aqueous solution in step S1 is 0.2-2.0 mol / L.

3. The method of claim 1, wherein the method further comprises: In step S2, one or a combination of the following conditions is included: ​ The preparation method of the first precipitant aqueous solution is specifically as follows: according to the proportion, a carbonate and an alkaline hydroxide are added to deionized water to stir and dissolve, and then diluted to prepare a first precipitant aqueous solution; wherein the molar ratio between the carbonate and the alkaline hydroxide is (0.2-1.5):1, and the total concentration of metal ions in the prepared first precipitant aqueous solution is 2.0-6.0 mol / L; The temperature of the parallel flow precipitation is 10-40℃, and the pH value of the parallel flow precipitation is 9-13; The heating and aging temperature is 60-95℃, and the heating and aging time is 2-24h; The calcination temperature is 500-800℃, and the calcination time is 3-8h.

4. The method of claim 3, wherein the method further comprises: The carbonate comprises one or a combination of sodium carbonate and potassium carbonate, and the alkaline hydroxide comprises one or a combination of sodium hydroxide and potassium hydroxide.

5. The method of claim 1, wherein the method is characterized by: The total concentration of metal ions in the second active metal mixed aqueous solution prepared in step S3 is 0.2-2.0 mol / L.

6. The method of claim 1, wherein the method is characterized by: In step S4, one or a combination of the following conditions is included: The second precipitant aqueous solution is a mixed aqueous solution of sodium carbonate and sodium hydroxide, and the molar ratio between the sodium carbonate and the sodium hydroxide is (0.5-1.5):1; The total concentration of metal ions in the second precipitant aqueous solution is 1.5-5.0 mol / L; The temperature of the parallel flow precipitation is 10-40 DEG C, and the pH value of the parallel flow precipitation is 9-13; The temperature of the heating aging is 60-95 DEG C, and the time of the heating aging is 2-24 h; The temperature of the calcination is 400-500 DEG C, and the time of the calcination is 4-12 h.

7. The use of the oxygen-resistant nickel-based bifunctional material prepared according to the preparation method of the oxygen-resistant nickel-based bifunctional material in any one of claims 1-6, characterized in that, The application of the oxygen-resistant nickel-based bifunctional material in the preparation of methane by integrating carbon dioxide capture and conversion of oxygen-containing flue gas, and the process of preparing methane by integrating carbon dioxide capture and conversion of oxygen-containing flue gas is carried out under constant temperature conditions of 200-350 DEG C.

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