Bi19Br3S27-NiSX catalyst, preparation method thereof and application of Bi19Br3S27-NiSX catalyst in production of ethylene through photo-thermal CO2 reduction

Abstract

The invention relates to a Bi19Br3S27-NiSX catalyst. In the Bi19Br3S27-NiSX catalyst, an amorphous phase NiSX is loaded on a crystal phase Bi19Br3S27. The preparation method of the catalyst comprises the following steps: taking bismuth salt and nickel salt as raw materials, dissolving the raw materials into ethylene glycol, and then adding a sulfur source and a bromine source to obtain a mixed solution; and carrying out solvothermal reaction on the mixed solution to obtain the Bi19Br3S27-NiSX catalyst. The invention relates to a Bi19Br3S27-NiSX catalyst which is applied to production of ethylene through photo-thermal CO2 reduction. The catalyst has the beneficial effects that the catalyst has excellent sunlight full-spectrum light absorption property and photo-thermal conversion capacity, the surface activity of the catalyst is remarkably improved through introduction of the NiSX amorphous phase, the electron transfer efficiency in catalytic reaction is enhanced, the light energy utilization efficiency is improved through the synergistic effect of the multi-component catalyst, and CO2 is subjected to high-selectivity catalytic reduction to produce ethylene.

Description

Technical Field

[0001] This invention relates to the field of photothermal catalysis technology, specifically to a Bi 19 Br3S 27 -NiS X Catalysts, preparation methods, and their application in photothermal CO2 reduction to ethylene. Background Technology

[0002] Carbon dioxide (CO2), as one of the major greenhouse gases, is a key factor contributing to global climate change and environmental degradation due to its excessive emissions. Therefore, CO2 conversion and resource utilization have become a core research direction for addressing climate change and the energy crisis. Traditional CO2 treatment methods, such as physical adsorption and chemical absorption, have achieved some success in certain applications, but their energy efficiency and economic viability still need improvement. In recent years, photocatalysis and photothermal catalysis technologies have become important technological pathways in CO2 reduction reactions due to their ability to utilize renewable energy sources such as solar energy. Through photocatalysis and photothermal catalysis, CO2 can be converted into useful chemicals, such as methanol and ethylene, thereby realizing the resource utilization of CO2 and effectively mitigating the greenhouse effect and energy shortage problems.

[0003] In photothermal catalysis, the design, structure, and performance regulation of catalysts are key factors in improving reaction efficiency and selectivity. Currently, most existing photothermal catalysts are based on metals or metal oxides. Although these materials can catalyze CO2 reduction under certain conditions, there are still many challenges in improving catalytic efficiency and selectivity, especially in the regulation of amorphous materials and the synergistic effect of multi-component catalysts, which lack in-depth research. Due to their unique surface structure, amorphous materials often exhibit high reactivity, which provides potential for improving catalyst performance. Multi-component catalysts, through the synergistic effect between different components, can effectively improve the rate and selectivity of catalytic reactions, especially in photothermal catalysis, where they can enhance the photothermal activation effect of the reaction.

[0004] Developing novel catalyst materials, especially those that can effectively improve the efficiency of photothermal catalytic CO2 reduction reaction and increase ethylene yield, has significant theoretical research value and broad application prospects. Technological innovation in this field will provide more efficient and economical solutions for CO2 conversion and utilization, and is of great significance to addressing global climate change. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a Bi 19 Br3S 27 -NiS X Catalysts, their preparation methods, and their application in photothermal CO2 reduction to ethylene production are proposed to overcome the shortcomings of existing technologies.

[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: A kind of Bi 19 Br3S 27 -NiS X Catalyst, Bi 19 Br3S 27 -NiS X Amorphous NiS in catalyst X Loaded on crystalline Bi 19 Br3S 27 superior.

[0007] Based on the above technical solution, the present invention can be further improved as follows.

[0008] Furthermore, Bi 19 Br3S 27 -NiS X Amorphous NiS in catalyst X The load is Bi 19 Br3S 27 1% to 40% of the molar amount.

[0009] Furthermore, Bi 19 Br3S 27 -NiS X Amorphous NiS in catalyst X The load is Bi 19 Br3S 27 5% to 20% of the molar amount.

[0010] Furthermore, Bi 19 Br3S 27 -NiS X Amorphous NiS in catalyst X The load is Bi 19 Br3S 27 5% to 15% of the molar amount.

[0011] Based on the above technical solution, the present invention also provides a Bi 19 Br3S 27 -NiS X The catalyst preparation method includes the following steps: S10. Using bismuth salt and nickel salt as raw materials, dissolve them in ethylene glycol, then add sulfur source and bromine source, dissolve and mix evenly to obtain a mixed solution; S20. By subjecting the mixed solution to a solvothermal reaction, Bi can be obtained. 19 Br3S 27 -NiS X catalyst.

[0012] Furthermore, the bismuth salt is a bismuth-containing soluble salt or its hydrate, the nickel salt is a nickel-containing soluble salt or its hydrate, the sulfur source is elemental sulfur and / or organic sulfur compounds, and the bromine source is one or more of liquid bromine, bromine salts, and bromine hydrocarbons.

[0013] Furthermore, the bismuth-containing soluble salt or its hydrate is bismuth nitrate, bismuth chloride, bismuth sulfate, bismuth bromide, or bismuth sulfide; the nickel-containing soluble salt or its hydrate is nickel nitrate, nickel chloride, or nickel sulfate; the organic sulfur compound is one or more of thiols, thioethers, thiophenols, disulfides, polysulfides, or thiocarbonyl compounds; and the bromine source is one or more of hexadecylammonium bromide, sodium bromide, potassium bromide, bismuth bromide, or dibromoethane.

[0014] Furthermore, the organosulfur compound is one or more of thiourea, thioacetamide, and thioacetone.

[0015] Furthermore, the concentration of Bi in the solution obtained after dissolving bismuth and nickel salts in ethylene glycol is 0.001 mol·L⁻¹. -1 ~0.1mol·L -1 The concentration of Ni is 0.0001 mol·L⁻¹. -1 ~0.01mol·L -1 .

[0016] Furthermore, S20 specifically involves: transferring the mixed solution into a reaction vessel, sealing it, conducting a solvothermal reaction, cooling to room temperature after the reaction is complete, collecting the precipitate, washing and drying it to obtain Bi. 19 Br3S 27 -NiS X catalyst.

[0017] Furthermore, the reaction temperature of the solvothermal reaction is 100℃~240℃, and the reaction time is 8h~48h.

[0018] Based on the above technical solution, the present invention also provides a Bi 19 Br3S 27 -NiS X Application of catalysts, Bi 19 Br3S 27 -NiS X The catalyst is used in the photothermal CO2 reduction to produce ethylene.

[0019] Furthermore, the specific process of photothermal CO2 reduction to ethylene is as follows: Weigh Bi 19 Br3S 27 -NiS XThe catalyst is dispersed in a sealed reaction vessel, and deionized water is added. The reaction vessel is then evacuated, and high-purity CO2 gas is introduced at a pressure equal to one atmosphere. A xenon lamp is used as a full-spectrum light source for photocatalysis to achieve photothermal CO2 reduction to ethylene.

[0020] The beneficial effects of this invention are: Bi 19 Br3S 27 -NiS X The catalyst possesses excellent full-spectrum solar light absorption properties and photothermal conversion capabilities; NiS X The introduction of the amorphous phase significantly enhances the surface activity of the catalyst and strengthens the electron transfer efficiency in the catalytic reaction. The synergistic effect of the multi-component catalyst improves the light energy utilization efficiency in the photothermal catalysis process, achieving highly selective catalytic reduction of CO2 to ethylene, with C2H4 and CO generation rates of 17.4 μmolg. -1 h -1 and 1.35umolg -1 h -1 The selectivity for generating C2H4 is as high as 92.7%, and when Bi is irradiated with full-spectrum light, 19 Br3S 27 -NiS X The surface temperature of the catalyst stabilizes at around 220℃, indicating that the catalyst of this invention has excellent photothermal conversion capabilities. Electrons enriched at the Bi sites can promote intermolecular coupling of CO2 to generate ethylene. Meanwhile, the amorphous NiS... X The introduction of [the catalyst] also provides additional active sites, which is beneficial for the stable adsorption of CO2 reduction intermediates and further CC-coupling reactions. This type of catalysis, as a photochemical-dominated form, not only overcomes the limitations of single photocatalysis and pure thermal catalysis, but also has high safety and low energy costs, aligning with sustainable energy development strategies and possessing broad application prospects. 19 Br3S 27 -NiS X The catalyst is synthesized in one step by a simple solvothermal method. The operation is simple and the raw materials are inexpensive. In the photothermal catalytic reduction of CO2, the amount of catalyst used is small and it can be recycled for a long time, which has the characteristics of sustainable development. Attached Figure Description

[0021] Figure 1 Bi in this invention 19 Br3S 27 -NiS X Flowchart of catalyst preparation method; Figure 2 The Bi prepared in Examples 1 to 8 of this invention are respectively 19 Br3S 27 -NiSX XRD pattern of the catalyst; Figure 3 The Bi prepared in Examples 1 to 8 of this invention are respectively 19 Br3S 27 -NiS X TEM spectrum of the catalyst; Figure 4 The Bi prepared in Examples 1 to 8 of this invention are respectively 19 Br3S 27 -NiS X Graph showing the effect of photothermal CO2 reduction by catalyst; Figure 5 The Bi prepared in Examples 1 to 8 of this invention are respectively 19 Br3S 27 -NiS X Graph showing the surface temperature change of the catalyst under full-spectrum illumination. Detailed Implementation

[0022] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0023] Example 1 like Figure 1 As shown, a Bi 19 Br3S 27 -NiS X The catalyst preparation method includes the following steps: Dissolve 0.064 g Bi(NO)3·5H2O and 0.02 g Ni(NO3)2·6H2O in 80 mL of ethylene glycol mixed solution and stir at room temperature to obtain a homogeneous solution; Add 0.14g thiourea and 0.61g potassium bromide, and stir to dissolve and mix evenly; The mixture was then transferred to a 90 mL polytetrafluoroethylene (PTFE) reactor, sealed, and placed in a drying oven for a solvothermal reaction. The reaction temperature was 100℃–240℃, and the reaction time was 8–48 h. A preferred reaction temperature was 130℃, and the reaction time was 12 h. After the reaction, the mixture was cooled to room temperature, the precipitate was collected, washed, and dried to obtain Bi. 19 Br3S 27 -NiS X Catalyst, denoted as Bi 19 Br3S 27 -8NiS X Bi 19 Br3S 27 -NiS X The catalyst is crystalline-amorphous Bi. 19Br3S 27 -NiS X Catalyst, NiS X NiS is an amorphous phase. X Compared to Bi 19 Br3S 27 The loading amount is controlled by the molar ratio of Ni to Bi.

[0024] Example 2 The difference between this embodiment and Example 1 is that the amount of Ni(NO3)2·6H2O is changed to 11 mg, and the resulting catalyst is denoted as Bi. 19 Br3S 27 -4NiS X .

[0025] Example 3 The difference between this embodiment and Example 1 is that the amount of Ni(NO3)2·6H2O is changed to 17 mg, and the resulting catalyst is denoted as Bi. 19 Br3S 27 -6NiS X .

[0026] Example 4 The difference between this embodiment and Example 1 is that the amount of Ni(NO3)2·6H2O is changed to 28 mg, and the resulting catalyst is denoted as Bi. 19 Br3S 27 -10NiS X .

[0027] Example 5 The difference between this embodiment and Example 1 is that the amount of Ni(NO3)2·6H2O is changed to 34 mg, and the resulting catalyst is denoted as Bi. 19 Br3S 27 -12NiS X .

[0028] Example 6 The difference between this embodiment and Example 1 is that the amount of Ni(NO3)2·6H2O is changed to 0 mg, and the resulting catalyst is denoted as Bi. 19 Br3S 27 .

[0029] Example 7 The difference between this embodiment and Example 1 is that the amount of Ni(NO3)2·6H2O is changed to 100mg, and the amount of Bi(NO)3·5H2O is 320mg. The resulting catalyst is denoted as Bi. 19 Br3S 27 -NiS X -8 (Bi in Examples 1-6)19 Br3S 27 -NiS X The preceding numbers are named according to the molar ratio. The molar ratio of Example 2 is the same as that of Example 7. To avoid confusion, the number of Example 7 is placed at the end.

[0030] Example 8 The difference between this embodiment and Embodiment 1 is that 0.064g Bi(NO)3·5H2O is replaced with one of 0.09g Bi2(SO4)3, 0.05g BiBr3, or 0.06g Bi2S3.

[0031] Example 9 The difference between this embodiment and Embodiment 1 is that 0.02g Ni(NO3)2·6H2O is replaced with one of 0.02g NiCl2·6H2O or 0.02g NiSO4·7H2O.

[0032] Example 10 The difference between this embodiment and Embodiment 1 is that 0.14g of thiourea is replaced with one of 0.12g of thioacetamide or 0.13g of thioacetone.

[0033] Example 11 The difference between this embodiment and Example 1 is that 0.61g potassium bromide is replaced with one of the following: 1.8g cetylammonium bromide, 0.5g sodium bromide, 0.6g bismuth bromide, or 0.9g dibromoethane.

[0034] Application example: Using different crystalline-amorphous phases of Bi 19 Br3S 27 -NiS X The catalyst includes the following steps: weighing 50 mg Bi 19 Br3S 27 -NiS X The catalyst was ultrasonically dispersed in 1 mL of deionized water to form a suspension. The suspension was drop-coated onto a 2.5 cm × 2.5 cm tray and dried in a 60 °C oven. The tray was then transferred to a 100 mL photothermal reactor, sealed, and CO2 was introduced into the quartz reactor to a pressure of 0.10 MPa. A xenon lamp was used as the light source, and the catalyst was kept at a consistent height from the light source. Different wavelength ranges of light were obtained by using filters to carry out the photothermal catalytic CO2 reduction reaction. Samples were taken every 1 hour for testing, and the gaseous products were analyzed using a gas chromatograph. The content of the products was determined by a flame ionization detector (FID).

[0035] like Figure 2As shown, the XRD diffraction peak shapes and positions of the seven samples are similar to those of Bi. 19 Br3S 27 Standard PDF cards correspond one-to-one, among which NiS X Bi is an amorphous phase, thus after the addition of a nickel source, 19 Br3S 27 -NiS X The XRD standard spectrum shows a broadened peak shape, indicating that the sample was successfully synthesized and that the sample purity is relatively high.

[0036] like Figure 3 As shown, the original Bi 19 Br3S 27 The morphology is a smooth needle tip, while after adding a nickel source, the obtained Bi... 19 Br3S 27 -NiS X The morphology consists of a smooth needle tip coated with an amorphous material with a thickness of 20nm to 40nm. EDS-mapping analysis shows that Bi... 19 Br3S 27 The outer layer is composed of Ni and S elements, exhibiting a distinct core-shell structure. As shown in the image, the Ni content decreases progressively from the edges to the center, while Br and Bi show higher content in the center and lower content at the edges. The S content, however, shows relatively little variation, further indicating that this amorphous phase is NiS. X .

[0037] like Figure 4 As shown, Bi prepared in Example 1 19 Br3S 27 -8NiS X The catalyst is the optimal catalyst, achieving C2H4 and CO production rates of 17.4 μmol / g. -1 h -1 and 1.35umolg -1 h -1 The selectivity for generating C2H4 was as high as 92.7%, as demonstrated by the Bi prepared in Example 6. 19 Br3S 27 The corresponding reduction product C2H4 formation rate is 0.58 μmolg. -1 h -1 The selectivity was only 32.4%, indicating that the crystalline-amorphous phase Bi... 19 Br3S 27 -8NiS X The catalyst exhibits extremely high activity and selectivity for the photothermal catalytic reduction of CO2 to ethylene.

[0038] Figure 5 Display Bi 19Br3S 27 -8NiS X The surface temperature of the catalyst under illumination in different wavelength ranges, and the temperature of Bi under full-spectrum illumination. 19 Br3S 27 -8NiS X The surface temperature of the catalyst is stable at around 220°C, indicating that the catalyst of this invention has excellent photothermal conversion capability.

[0039] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A Bi 19 Br3S 27 -NiS X Catalyst, characterized in that, Bi 19 Br3S 27 -NiS X Amorphous NiS in catalyst X Loaded on crystalline Bi 19 Br3S 27 superior.

2. The Bi according to claim 1 19 Br3S 27 -NiS X Catalyst, characterized in that, Bi 19 Br3S 27 -NiS X Amorphous NiS in catalyst X The load is Bi 19 Br3S 27 1% to 40% of the molar amount.

3. The Bi according to claim 2 19 Br3S 27 -NiS X Catalyst, characterized in that, Bi 19 Br3S 27 -NiS X Amorphous NiS in catalyst X The load is Bi 19 Br3S 27 5% to 20% of the molar amount.

4. The Bi according to claim 3 19 Br3S 27 -NiS X Catalyst, characterized in that, Bi 19 Br3S 27 -NiS X Amorphous NiS in catalyst X The load is Bi 19 Br3S 27 5% to 15% of the molar amount.

5. A Bi as described in any one of claims 1 to 4 19 Br3S 27 -NiS X A method for preparing a catalyst, characterized in that, Includes the following steps: S10. Using bismuth salt and nickel salt as raw materials, dissolve them in ethylene glycol, then add sulfur source and bromine source, dissolve and mix evenly to obtain a mixed solution; S20. By subjecting the mixed solution to a solvothermal reaction, Bi can be obtained. 19 Br3S 27 -NiS X catalyst.

6. The preparation method according to claim 5, characterized in that, The bismuth salt is a bismuth-containing soluble salt or its hydrate, the nickel salt is a nickel-containing soluble salt or its hydrate, the sulfur source is elemental sulfur and / or an organic sulfur compound, and the bromine source is one or more of liquid bromine, bromine salts, and bromine hydrocarbons.

7. The preparation method according to claim 5, characterized in that: The bismuth-containing soluble salt or its hydrate is bismuth nitrate, bismuth chloride, bismuth sulfate, bismuth bromide or bismuth sulfide; the nickel-containing soluble salt or its hydrate is nickel nitrate, nickel chloride or nickel sulfate; the organic sulfur compound is one or more of thiols, thioethers, thiophenols, disulfides, polysulfides, thiocarbonyl compounds; and the bromine source is one or more of hexadecylammonium bromide, sodium bromide, potassium bromide, bismuth bromide, dibromoethane.

8. The preparation method according to claim 5, characterized in that, The concentration of Bi in the solution obtained after dissolving bismuth and nickel salts in ethylene glycol is 0.001 mol·L⁻¹. -1 ~0.1mol·L -1 The concentration of Ni is 0.0001 mol·L⁻¹. -1 ~0.01mol·L -1 .

9. The preparation method according to claim 5, characterized in that, The reaction temperature for the solvothermal reaction is 100℃~240℃, and the reaction time is 8h~48h.

10. A Bi as described in any one of claims 1 to 4 19 Br3S 27 -NiS X The catalyst or Bi prepared by the method according to any one of claims 5 to 9 19 Br3S 27 -NiS X The application of catalysts is characterized by, Bi 19 Br3S 27 -NiS X The catalyst is used in the photothermal CO2 reduction to produce ethylene.

Images