A cerium oxide core-shell nanowire catalytic material and its preparation method and application

Abstract

The invention discloses a cerium oxide core-shell nanowire catalytic material and its preparation method and application, palladium acetate and cobalt salt are dissolved in ethylene glycol aqueous solution, stirred to clarify, pH value is adjusted to 9 9.5, stirred and reacted to obtain a cobalt-stabilized palladium cluster nanowire precursor; a cerium source is dissolved in an ethanol aqueous solution, a cobalt-stabilized palladium cluster nanowire precursor is added, stirred evenly, a precipitant is added under heating, pH value is adjusted to 9 9.5, reflux reaction is performed to obtain a precipitate, roasting, and cerium oxide is wrapped around cobalt-stabilized palladium cluster nanowire catalyst. The cerium oxide shell of the present invention has better oxygen storage and oxygen release capacity. The catalyst obtained by the present invention has better low-temperature propane oxidation performance than the catalyst obtained by the prior art, and stability, water resistance and CO resistance are very good.

Description

Technical Field

[0001] The present invention relates to a cerium oxide core-shell nanowire catalytic material for oxidative elimination of light alkanes, and in particular to a cerium oxide core-shell nanowire catalytic material and a preparation method and application thereof. Background Art

[0002] Volatile organic compounds (VOCs) are the main components of air pollutants and are important precursors to secondary pollutants such as fine particulate matter (PM2.5) and ozone (O3). Non-methane low-carbon alkanes are an important type of VOCs, mainly derived from the petrochemical industry, associated natural gas, and motor vehicle exhaust emissions. They are easily reacted with nitrogen oxides (NO x ) and other factors, forming photochemical smog and causing secondary pollution. For VOC control and elimination, catalytic oxidation has become one of the primary purification methods due to its simplicity and limited generation of derivative pollutants. However, due to the high stability of CC and CH bonds in low-carbon alkane VOCs, molecular activation typically occurs at high temperatures. Therefore, low-carbon alkane combustion catalytic materials with high low-temperature activity and stability are currently a hot topic of research.

[0003] Efficient catalytic materials are a crucial step in solving this problem. Precious metal catalysts, especially Pd-based catalysts, show superior performance in the activation process of low-carbon alkanes, but they are expensive and their large-scale applications are limited. Non-precious metal catalysts, especially transition metal-based catalysts (Mn, Co, Cr, Ce, Cu, Mo, Fe, etc.) show good initial activity, but are easily deactivated during use and have poor stability. The selection of carriers is also a key link in the design of supported catalysts. Common carriers include acidic carriers such as aluminum oxide, solidified carriers such as silicon oxide and titanium oxide, and oxidizing carriers such as cerium oxide. Among them, rare earth metal cerium (Ce) is relatively active because of its 4f electrons, and its oxide also has Ce 3+ and Ce 4+ , allowing the formation of a large number of oxygen vacancies on the surface, which can anchor the loaded metal and improve the catalyst's stability. Furthermore, good oxygen mobility is also very beneficial for oxidation reactions, promoting the mineralization of pollutant molecules. In recent years, core-shell catalysts have become a relatively new class of nanomaterials that can controllably integrate the functions of complementary materials with optimized composition and morphology. Furthermore, core-shell catalysts can enhance catalytic activity and thermal stability, preventing sintering of active components, and are therefore widely favored by researchers. Summary of the Invention

[0004] In order to overcome the problems in the prior art, the purpose of the present invention is to provide a cerium oxide core-shell nanowire catalytic material and a preparation method and application thereof.

[0005] In order to achieve the above object, the technical solution of the present invention is as follows:

[0006] A method for preparing a cerium oxide core-shell nanowire catalytic material comprises the following steps:

[0007] Dissolving palladium acetate and cobalt salt in an ethylene glycol aqueous solution, stirring until the solution is clear, adjusting the pH to 9-9.5, and reacting after stirring to obtain a cobalt-stabilized palladium cluster nanowire precursor;

[0008] The cerium source is dissolved in an ethanol aqueous solution, a cobalt-stabilized palladium cluster nanowire precursor is added, and after stirring evenly, a precipitant is added under heating, the pH value is adjusted to 9-9.5, reflux reaction is carried out to obtain a precipitate, and calcination is performed to obtain a cerium oxide-coated cobalt-stabilized palladium cluster nanowire catalyst.

[0009] Furthermore, the cobalt salt is cobalt acetate or cobalt sulfate.

[0010] Furthermore, the molar ratio of palladium acetate to cobalt salt is 1:10.

[0011] Furthermore, the volume ratio of ethylene glycol to water in the ethylene glycol aqueous solution is 3:1.

[0012] Furthermore, the ratio of palladium acetate to ethylene glycol aqueous solution is 20-50 mmol:50 mL.

[0013] Furthermore, the reaction temperature is 165-175° C. and the reaction time is 23-25 ​​h.

[0014] Furthermore, the cerium source is cerium nitrate, the precipitant is hexamethylenetetramine, and the solvent is an ethanol aqueous solution.

[0015] Furthermore, the calcination temperature is 340-360° C., and the calcination time is 4-5 h; the temperature is increased from room temperature to 340-360° C. at a rate of 2-5° C. / min.

[0016] A cerium oxide core-shell nanowire catalytic material prepared according to the method described above.

[0017] The invention discloses an application of the cerium oxide core-shell nanowire catalytic material prepared according to the method described above in the oxidation and elimination of light alkanes.

[0018] Furthermore, 300 mg of cerium oxide core-shell nanowire catalytic material was placed in a quartz tube, and the reaction gas was introduced at a flow rate of 100 mL / min and a reaction space velocity of 20000 mL / h / g. cat , reacting at 200-500°C; wherein the volume percentage of propane in the reaction gas is 0.1%, the volume percentage of O2 is 20%, and the remaining gas is N2.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention uses palladium acetate and cobalt salt to prepare a cobalt-stabilized palladium cluster nanowire precursor, and then adds a cerium source ethanol aqueous solution to prepare a cerium oxide core-shell nanowire catalytic material. The material is a cerium oxide-wrapped cobalt-stabilized palladium cluster nanowire catalyst with good redox ability. The nanowires show the best oxidation performance compared to catalysts with other morphologies, and the core-shell structure can effectively prevent the loss and aggregation of the active components of the catalyst. Compared with the common core-shell material based on silica shell, the cerium oxide shell of the present invention has better oxygen storage and release capacity. Compared with the catalyst obtained by the prior art, the catalyst obtained by the present invention has better low-temperature propane oxidation performance, and is very good in stability, water resistance and CO resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The PdCoO of the present invention x -NW@CeO2、PdCoO x -NW / CeO2 and PdCoO x -Propane oxidation activity diagram of B / CeO2 catalyst.

[0022] Figure 2 The PdCoO of the present invention x -NW@CeO2 and PdCoO x -B / CeO2 catalyst propane oxidation stability test results.

[0023] Figure 3 PdCoO invented x -NW@CeO2、PdCoO x -NW / CeO2 and PdCoO x -Graph showing the ethane oxidation activity of B / CeO2 catalyst.

[0024] Figure 4 PdCoO in the present invention x -NW@CeO2、PdCoO x -NW / CeO2 and PdCoO x -Raman characterization results of B / CeO2 catalyst.

[0025] Figure 5 PdCoO in the present invention x -Schematic diagram of the synthesis of NW@CeO2 catalyst.

[0026] Figure 6 PdCoO x -HRTEM image of NW@CeO2 catalyst. DETAILED DESCRIPTION

[0027] The following embodiments and drawings will help to understand the present invention, but they do not limit the contents of the present invention.

[0028] The present invention provides a method for preparing a cerium oxide core-shell nanowire catalytic material, comprising the following steps:

[0029] 1) Using palladium acetate and cobalt acetate (or cobalt sulfate) as precursors, a hydrothermal reaction is carried out in an ethylene glycol aqueous solution solvent to obtain a cobalt-stabilized palladium cluster nanowire precursor; the specific process is as follows:

[0030] Palladium acetate and cobalt acetate (or cobalt sulfate) are dissolved in an ethylene glycol aqueous solution, stirred until clear, and then sodium carbonate solution is added dropwise to adjust the pH value to 9-9.5. The mixture is stirred for 2 hours, and the resulting precursor solution is then transferred to a reactor and reacted at 165-175°C for 23-25 ​​hours. Finally, the resulting solution is filtered and washed to obtain a cobalt-stabilized palladium cluster nanowire precursor.

[0031] Wherein, the molar ratio of palladium acetate to cobalt acetate (or cobalt sulfate) is 1:10;

[0032] The volume ratio of ethylene glycol to water in ethylene glycol aqueous solution is 3:1;

[0033] The ratio of palladium acetate to solvent is 20-50mmol:50mL;

[0034] 2) Using cerium nitrate as a cerium source, hexamethylenetetramine as a precipitant, and ethanol aqueous solution as a solvent, the nanowire precursor obtained above was added at 80°C and refluxed for 2 hours. The resulting solid was then centrifuged and washed, and calcined in a muffle furnace to obtain a cerium oxide-coated cobalt-stabilized palladium cluster nanowire catalyst, namely a cerium oxide core-shell nanowire catalytic material. The specific process is as follows:

[0035] Dissolve cerium nitrate in an ethanol aqueous solution, stir to clarify, add the cobalt-stabilized palladium cluster nanowire precursor obtained above, continue stirring for 20 minutes, heat to 80°C, then add the precipitant hexamethylenetetramine solution dropwise, adjust the pH value to 9-9.5, and condense and reflux for 2 hours under continuous stirring. The obtained mixed solution is centrifuged at a speed and time of 6000r / min for 15 minutes each time, and washed three times with ethanol and deionized water. After drying the obtained precipitate at 60°C for 12 hours, transfer it to a muffle furnace, heat it to 340-360°C at a rate of 2-5°C / min, and calcine it for 4-5 hours to obtain a cerium oxide core-shell nanowire catalytic material.

[0036] The mass percentage of palladium in the cerium oxide core-shell nanowire catalytic material is 1%;

[0037] An application of the cerium oxide core-shell nanowire catalytic material in the oxidation and elimination of light alkanes is as follows: 300 mg of the cerium oxide core-shell nanowire catalytic material is placed in a quartz tube, and a reaction gas is introduced at a flow rate of 100 mL / min and a reaction space velocity of 20000 mL / h / g. cat , reacting at 200-500°C; wherein the volume content of propane in the reaction gas is 0.1%, the volume content of O2 is 20%, and the remaining gas is N2.

[0038] Example 1

[0039] First, 10 mmol of cobalt acetate and 1 mmol of palladium acetate were weighed and added to 40 ml of ethylene glycol aqueous solution (volume ratio of ethylene glycol: water = 3:1). After stirring for 20 minutes, sodium carbonate solution was slowly added dropwise to adjust the pH to 9-9.5. Stirring was continued for 2 hours, and the mixture was transferred to a reactor and reacted at 170°C for 24 hours. The resulting mixture was then washed three times with deionized water and ethanol, and the resulting precipitate was dried at 60°C for 12 hours to obtain a cobalt-stabilized palladium cluster nanowire precursor.

[0040] 6.8162 g of cerium nitrate was added to 100 mL of ethanol aqueous solution (volume ratio of ethanol: water = 1: 1), and the above-obtained 0.08 g of cobalt-stabilized palladium cluster nanowire precursor was added, followed by dropwise addition of 0.2 g / mL of hexamethylenetetramine solution, adjustment of pH to 9-9.5, and condensation and reflux at 80 ° C for 2 h. The obtained mixture was centrifuged and washed three times with ethanol and deionized water, respectively, at a speed of 6000 r / min, and each centrifugation time was 15 minutes. After drying the obtained precipitate at 60 ° C for 12 h, it was transferred to a muffle furnace, heated to 350 ° C at a rate of 2-5 ° C / min, and calcined for 4 h to obtain cerium oxide-coated cobalt-stabilized palladium cluster nanowires (PdCoO x -NW@CeO2) catalyst.

[0041] The Pd loading (mass percentage) is 1%, and the molar ratio of Pd:Co is 1:10.

[0042] Comparative Example 1

[0043] First, 10 mmol of cobalt acetate and 1 mmol of palladium acetate were weighed and added to 40 ml of ethylene glycol aqueous solution (volume ratio of ethylene glycol: water = 3:1). After stirring for 20 minutes, sodium carbonate solution was slowly added dropwise to adjust the pH to 9-9.5. Stirring was continued for 2 hours, and the mixture was transferred to a reactor and reacted at 170°C for 24 hours. The resulting mixture was then washed three times with deionized water and ethanol, and the resulting precipitate was dried at 60°C for 12 hours to obtain a cobalt-stabilized palladium cluster nanowire precursor.

[0044] 6.81624 g of Ce(NO3)3·6H2O was weighed and dissolved in 100 mL of ethanol-water solution (volume ratio of ethanol: water = 1:1). Ammonia water was added dropwise to adjust the pH to 9-9.5 to obtain a light yellow precipitate. The mixture was stirred for 2 h. The obtained mixture was filtered and washed three times with deethanol and deionized water respectively. The obtained precipitate was then placed in a 60 ° C oven and dried for 12 h. Finally, it was transferred to a muffle furnace and heated from room temperature to 500 ° C at a heating rate of 2 ° C / min. It was calcined in air for 4 h to obtain a CeO2 carrier.

[0045] 0.2833 g of the cobalt-stabilized palladium cluster nanowire precursor obtained above was dissolved in 10 mL of deionized water, and then 1.8 g of the CeO2 carrier obtained above was added and stirred for 8 h. The mixture was then stirred and evaporated to dryness in an 80 ° C water bath, and the obtained mixture was dried in a 60 ° C oven for 12 h. Finally, it was transferred to a muffle furnace and heated from room temperature to 350 ° C at a heating rate of 2 ° C / min, and calcined in air for 4 h to obtain cerium oxide-supported cobalt-stabilized palladium cluster nanowires (PdCoO x -NW / CeO2) catalyst.

[0046] The Pd loading (mass percentage) is 1%, and the molar ratio of Pd:Co is 1:10.

[0047] The difference from Example 1 is that the catalyst obtained in Comparative Example 1 is a catalyst in which nanowires are supported on cerium oxide.

[0048] Comparative Example 2

[0049] 6.81624 g of Ce(NO3)3·6H2O was weighed and dissolved in 100 mL of ethanol-water solution (ethanol: water = 1:1). Ammonia water was added dropwise to adjust the pH to 9-9.5 to obtain a light yellow precipitate. The mixture was stirred for 2 h. The obtained mixture was filtered and washed three times with deethanol and deionized water respectively. The obtained precipitate was then placed in a 60 ° C oven and dried for 12 h. Finally, it was transferred to a muffle furnace and heated from room temperature to 500 ° C at a heating rate of 2 ° C / min. It was calcined in air for 4 h to obtain a CeO2 carrier.

[0050] 10 mmol of cobalt acetate and 1 mmol of palladium acetate were weighed and added to 20 ml of ethylene glycol aqueous solution (ethylene glycol: water = 3:1). After stirring to clarify, 2.7 g of the CeO2 carrier obtained above was added. After stirring for 8 hours, the obtained solution was stirred and evaporated to dryness in an 80 ° C water bath. The obtained mixture was dried in a 60 ° C oven for 12 hours and finally transferred to a muffle furnace. The temperature was raised from room temperature to 350 ° C at a heating rate of 2 ° C / min and calcined in air for 4 hours to obtain cerium oxide supported cobalt stabilized palladium clusters (PdCoO x -B / CeO2) catalyst.

[0051] Example 2

[0052] First, 10 mmol of cobalt sulfate and 1 mmol of palladium acetate were weighed and added to 40 ml of ethylene glycol aqueous solution (volume ratio of ethylene glycol to water = 3:1). After stirring for 20 minutes, sodium carbonate solution was slowly added dropwise to adjust the pH to 9. Stirring was continued for 2 hours, and the mixture was transferred to a reactor and reacted at 165°C for 25 hours. The resulting mixture was then washed three times with deionized water and three times with ethanol. The resulting precipitate was dried at 60°C for 12 hours to obtain a cobalt-stabilized palladium cluster nanowire precursor.

[0053] 6.8162 g of cerium nitrate was added to 100 mL of ethanol aqueous solution (volume ratio of ethanol: water = 1: 1), and the above-obtained 0.08 g of cobalt-stabilized palladium cluster nanowire precursor was added, followed by dropwise addition of 0.2 g / mL of hexamethylenetetramine solution, adjustment of pH to 9.5, and condensation and reflux at 80 ° C for 2 h. The obtained mixture was centrifuged and washed three times with ethanol and deionized water, respectively, at a speed of 6000 r / min, and each centrifugation time was 15 minutes. After drying the obtained precipitate at 60 ° C for 12 h, it was transferred to a muffle furnace, heated to 340 ° C at a rate of 5 ° C / min, and calcined for 5 h to obtain cerium oxide-coated cobalt-stabilized palladium cluster nanowires (PdCoO x -NW@CeO2) catalyst.

[0054] Example 3

[0055] First, 10 mmol of cobalt acetate and 1 mmol of palladium acetate were weighed and added to 40 ml of ethylene glycol aqueous solution (volume ratio of ethylene glycol: water = 3:1). After stirring for 20 minutes, sodium carbonate solution was slowly added dropwise to adjust the pH to 9.5. Stirring was continued for 2 hours, and the mixture was transferred to a reactor and reacted at 175°C for 23 hours. The resulting mixture was then washed three times with deionized water and ethanol, and the resulting precipitate was dried at 60°C for 12 hours to obtain a cobalt-stabilized palladium cluster nanowire precursor.

[0056] 6.8162 g of cerium nitrate was added to 100 mL of ethanol aqueous solution (volume ratio of ethanol: water = 1: 1), and 0.08 g of the cobalt-stabilized palladium cluster nanowire precursor obtained above was added, followed by dropwise addition of 0.2 g / mL of hexamethylenetetramine solution, adjustment to pH 9, and condensation reflux at 80 ° C for 2 h. The obtained mixture was centrifuged and washed three times with ethanol and deionized water, respectively, at a speed of 6000 r / min, and each centrifugation time was 15 minutes. After drying the obtained precipitate at 60 ° C for 12 h, it was transferred to a muffle furnace, heated to 360 ° C at a rate of 2 ° C / min, and calcined for 4 h to obtain cerium oxide-coated cobalt-stabilized palladium cluster nanowires (PdCoO x -NW@CeO2) catalyst.

[0057] The oxidation of light alkanes in Example 1, Comparative Example 1 and Comparative Example 2 was carried out in a fixed bed reactor. First, 300 mg of a catalyst with a particle size of 40-60 mesh was weighed and placed in a quartz tube. A reaction gas of 1000 ppm C3H8 + 20% O2 / N2 (100 mL / min, GHSV = 20000 mL / h / g) was introduced. cat ), the test temperature range is 150-360℃, and the tail gas is detected by gas chromatograph equipped with FID detector.

[0058] The catalysts were characterized by Raman spectroscopy and high-resolution transmission electron microscopy.

[0059] Figure 1 The propane oxidation activity results of Example 1, Comparative Example 1 and Comparative Example 2 are shown in the figure. As can be seen from the figure, the activity of the catalyst increases with the increase of reaction temperature. x The temperature for 90% propane conversion over the NW@CeO2 catalyst is 240℃, while that over the PdCoO x -NW / CeO2 catalyst and PdCoO x The propane conversion rate of the -B / CeO2 catalyst is 90% at temperatures of 320 and 330°C. x -NW@CeO2 catalyst can completely convert propane at 250℃, while PdCoO x -NW / CeO2 catalyst and PdCoO x -B / CeO2 catalyst needs to be above 350℃ to fully convert propane.

[0060] In order to further illustrate the stability of the cerium oxide-coated cobalt-stabilized palladium cluster nanowire catalyst, the stability tests were carried out on Example 1 and Comparative Example 2 at the temperatures when their respective conversion rates were 90%. Figure 2 As shown. According to the stability results, PdCoO x -NW@CeO2 catalyst showed good stability and could maintain a high conversion rate after the introduction of water and CO, and there was no significant change after 50h of testing. x For the -B / CeO2 catalyst, even without the introduction of other impurity gases, its conversion rate has been declining, from the initial 92% to 85% after 30h. The stability test results show that the cerium oxide wrapped cobalt stabilized palladium cluster nanowires (PdCoO x -NW@CeO2) catalyst has good stability and resistance to water and CO.

[0061] Figure 3The graphs are the results of ethane oxidation activity of Example 1, Comparative Example 1 and Comparative Example 2. According to the results of ethane oxidation, it can be seen that as the reaction temperature increases, the ethane conversion rate gradually increases. x The temperature for 90% ethane conversion over the NW@CeO2 catalyst is 280℃, while that over the PdCoO x -NW / CeO2 catalyst and PdCoO x The temperature at which the ethane conversion rate of the -B / CeO2 catalyst reaches 90% is 360℃. x -NW@CeO2 catalyst can completely convert ethane at 320℃, while PdCoO x -NW / CeO2 catalyst and PdCoO x -B / CeO2 catalyst needs to be above 420℃ to completely convert ethane. According to the results of propane and ethane oxidation, PdCoO x -NW@CeO2 catalyst exhibits better light alkane oxidation performance than catalysts obtained by traditional impregnation and precipitation methods.

[0062] Figure 4 The Raman spectra of Example 1, Comparative Example 1 and Comparative Example 2 are shown in Figure 1. According to the Raman results, the 460, 600, and 698 cm-1 wavelengths can be observed on all samples. -1 The vibration peaks at 3 and 4 are respectively attributed to the F 2g Mode vibration, oxygen vacancies and F in Co3O4 crystals 2g Mode vibration. Usually, I Ov / I F2g It can be used to reveal the oxygen vacancy concentration on the catalyst surface. According to calculations, PdCoO x -NW@CeO2、PdCoO x -NW / CeO2 and PdCoO x -B / CeO2 catalyst Ov / I F2g 0.22, 0.20, and 0.16 respectively. Compared with the catalysts prepared by traditional impregnation and precipitation methods, the PdCoO x -NW@CeO2 catalytic material has a higher oxygen vacancy concentration, which is conducive to the oxidation reaction.

[0063] Figure 5 PdCoO x -Schematic diagram of the synthesis of NW@CeO2 catalytic materials. Figure 6 PdCoO x -HRTEM image of NW@CeO2 catalytic material, from Figure 5 and Figure 6It can be seen that there are obvious nanowire morphology, and the light-colored particles around the black nanowires can be attributed to CeO2, indicating that PdCoO x -NW@CeO2 catalytic material has a microscopic morphology of core-shell wrapped nanowires.

[0064] The above description is merely a description of the preferred embodiment of the present invention and is not to be construed as limiting the claims. The present invention is not limited to the above embodiment, and variations in the specific structure are permitted. Any variations made within the scope of the independent claims of the present invention are also within the scope of protection of the present invention.

[0065] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

Claims

1. A method for preparing a cerium oxide core-shell nanowire catalytic material, characterized in that: The following steps are involved: Dissolving palladium acetate and cobalt salt in an ethylene glycol aqueous solution, stirring until clear, adjusting the pH to 9-9.5, and then stirring to perform a hydrothermal reaction to obtain a cobalt-stabilized palladium cluster nanowire precursor; wherein the hydrothermal reaction temperature is 165-175° C. and the reaction time is 23-25 ​​hours; The cerium source is dissolved in an ethanol aqueous solution, a cobalt-stabilized palladium cluster nanowire precursor is added, and after stirring evenly, a precipitant is added under heating, and the pH value is adjusted to 9-9.

5. A reflux reaction is performed to obtain a precipitate, which is calcined to obtain a cerium oxide core-shell nanowire catalytic material.

2. The method for preparing a cerium oxide core-shell nanowire catalytic material according to claim 1, characterized in that: The cobalt salt is cobalt acetate or cobalt sulfate.

3. The method for preparing a cerium oxide core-shell nanowire catalytic material according to claim 1, characterized in that: The molar ratio of palladium acetate to cobalt salt was 1:

10.

4. The method for preparing a cerium oxide core-shell nanowire catalytic material according to claim 1, wherein: The volume ratio of ethylene glycol to water in the ethylene glycol aqueous solution is 3:

1.

5. The method for preparing a cerium oxide core-shell nanowire catalytic material according to claim 1, characterized in that: The usage ratio of palladium acetate to ethylene glycol aqueous solution is 20-50mmol:50mL.

6. The method for preparing a cerium oxide core-shell nanowire catalytic material according to claim 1, characterized in that: The cerium source is cerium nitrate, the precipitant is hexamethylenetetramine, and the solvent is ethanol aqueous solution.

7. The method for preparing a cerium oxide core-shell nanowire catalytic material according to claim 1, characterized in that: The calcination temperature is 340-360°C, and the time is 4-5h; the temperature is increased from room temperature to 340-360°C at a rate of 2-5°C / min.

8. A cerium oxide core-shell nanowire catalytic material prepared according to the method according to any one of claims 1 to 7.

9. Use of a cerium oxide core-shell nanowire catalytic material prepared according to the method of any one of claims 1 to 7 in the oxidation and elimination of light alkanes.

Images