A non-noble metal composite oxide catalyst, a method for preparing the same, and use thereof

Abstract

The present application relates to a non-noble metal composite oxide catalyst and its preparation method and use, the non-noble metal composite oxide catalyst is Ce x Cu y O2 catalyst, wherein, x+y=1, 0.05≤y≤0.55.The present application utilizes Cu element to promote the redox capacity of the non-noble metal catalyst, the NH3 conversion rate of the catalyst is all above 80% under the condition of 250 DEG C, the N2 selectivity is all above 87% under the condition of 200 DEG C, further preferably, the NH3 conversion rate is all above 95% under the condition of 250 DEG C, when the temperature is higher than 250 DEG C, the NH3 conversion rate is still all above 95%, and the non-noble metal composite oxide catalyst has high selectivity to N2 in the process of catalyzing NH3 conversion, meets the current market application demand.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of catalytic materials, in particular to a non-noble metal composite oxide catalyst and a preparation method and application thereof. BACKGROUND

[0002] The emission of ammonia (NH3) has a serious impact on the ecosystem, such as NH3 can promote the formation of sulfate and secondary organic aerosols in the atmosphere, which is an important cause of haze pollution. There are many sources of ammonia emission, mainly including agriculture, industry and transportation, among which the emission of NH3 in motor vehicle exhaust is considered to be the main source of NH3 in the city, especially the diesel vehicle exhaust using urea selective catalytic reduction (NH3-SCR) denitration technology, NH3 escape is easy to occur in the process of using NH3-SCR, so it is necessary to install NH3 purification device at the end of NH3-SCR purification system.

[0003] At present, NH3 selective catalytic oxidation (NH3-SCO) technology is an effective and economic measure to remove NH3, and the core is a high-efficiency and stable NH3-SCO catalyst. NH3-SCO catalysts include noble metal catalysts, transition metal catalysts, composite oxide catalysts and molecular sieve catalysts. Among them, the most commonly used NH3-SCO commercial catalyst is a noble metal catalyst, however, the noble metal catalyst has the disadvantages of poor N2 selectivity, high cost and insufficient thermal stability.

[0004] CN117753409A discloses a noble metal silver-based NH3-SCO catalyst and its preparation method and application, which improves the low-temperature activity, but still has poor N2 selectivity; CN111068764A discloses a NH3-SCO catalyst Co-Cu / Beta for diesel vehicle exhaust, which is prepared by impregnation method, and although it can improve the NH3 conversion activity and N2 selectivity to a certain extent, its structural stability is easily destroyed at high temperature; CN109289889A discloses a supported noble metal Pt supported catalyst, which has a relatively high content of noble metal Pt, high cost and relatively poor N2 selectivity, and exists side reactions, which easily generates by-products such as NO, N2O and NO2.

[0005] Therefore, how to develop a non-noble metal NH3-SCO catalyst with high NH3 conversion activity, high N2 selectivity and high stability has become a problem to be solved at present. SUMMARY

[0006] To solve the above technical problems, the purpose of the present application is to provide a non-noble metal composite oxide catalyst and a preparation method and application thereof, the non-noble metal composite oxide catalyst is Ce x Cu yThe O2 catalyst, wherein x+y=1, 0.05≤y≤0.55, utilizes Cu element to promote the redox ability of the non-precious metal catalyst. The catalyst achieves an NH3 conversion rate of over 80% at 250℃ and an N2 selectivity of over 87% at 200℃. More preferably, the NH3 conversion rate is over 95% at 250℃. When the temperature is higher than 250℃, the NH3 conversion rate remains above 95%. Furthermore, the non-precious metal composite oxide catalyst exhibits high selectivity for N2 during the catalytic conversion of NH3.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a non-noble metal composite oxide catalyst, wherein the non-noble metal composite oxide catalyst is Ce. x Cu y O2 catalyst, where x+y=1, 0.05≤y≤0.55, and y can be, for example, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5 or 0.55, etc.

[0009] This invention uses Cu as a modifying element. On the one hand, Cu increases oxygen vacancies, thus increasing catalytic active sites; on the other hand, Cu has high activity and can itself serve as an active site. Therefore, the presence of Cu increases the surface active site density of the catalyst, enhances catalytic activity, and effectively promotes the redox capability of the non-noble metal catalyst.

[0010] The non-precious metal composite oxide catalyst of this invention is used as an NH3-SCO catalyst, which can oxidize NH3 to N2 and H2O. The NH3 conversion rate of the catalyst is above 80% at 250℃ and the N2 selectivity is above 87% at 200℃. More preferably, the NH3 conversion rate is above 95% at 250℃. When the temperature is higher than 250℃, the NH3 conversion rate is still above 95%, which shows good low-temperature activity, N2 selectivity and stability.

[0011] Preferably, the Ce x Cu y The O2 catalyst has a nanorod morphology.

[0012] Secondly, the present invention also provides a method for preparing the non-noble metal composite oxide catalyst described in the first aspect, the method comprising the following steps:

[0013] (1) Mix the soluble cerium salt, soluble copper salt and solvent evenly to obtain a mixed solution containing cerium and copper;

[0014] (2) Mix the precipitant solution with the cerium and copper mixed solution described in step (1) evenly, perform hydrothermal reaction, and obtain the hydrothermal reaction product by solid-liquid separation;

[0015] (3) The hydrothermal reaction product described in step (2) is calcined to obtain a non-precious metal composite oxide catalyst.

[0016] Preferably, the soluble cerium salt in step (1) includes any one or a combination of at least two of cerium nitrate hexahydrate, cerium carbonate, or cerium oxalate.

[0017] Preferably, the soluble copper salt in step (1) includes any one or a combination of at least two of copper nitrate trihydrate, copper carbonate, or copper oxalate.

[0018] Preferably, in step (1), the molar ratio of Ce to Cu in the cerium-containing and copper-containing mixed solution is x:y, where x+y=1, 0.05≤y≤0.55, and the molar ratio x:y can be, for example, 0.45:0.55, 0.5:0.5, 0.55:0.45, 0.6:0.4, 0.65:0.35, 0.7:0.3, 0.75:0.25, 0.8:0.2, 0.85:0.15, 0.9:0.1, or 0.95:0.05, etc.

[0019] Preferably, the solvent in step (1) includes deionized water.

[0020] Preferably, the precipitant solution in step (2) includes any one or a combination of at least two of the following: an aqueous solution of sodium hydroxide, an aqueous solution of ammonia, or an aqueous solution of urea.

[0021] Preferably, the mixing method in step (2) includes adding the precipitant solution to the cerium- and copper-containing mixed solution in step (1).

[0022] Preferably, the addition is accompanied by continuous stirring.

[0023] Preferably, the temperature of the hydrothermal reaction in step (2) is 80 to 120°C, such as 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C or 120°C.

[0024] Preferably, the hydrothermal reaction time in step (2) is 8 to 16 hours, for example, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 13 hours, 14 hours, 15 hours or 16 hours.

[0025] Preferably, the solid-liquid separation in step (2) includes vacuum filtration.

[0026] Preferably, step (2) further includes washing and drying steps after solid-liquid separation.

[0027] Preferably, the drying temperature is 80-120°C, such as 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, or 120°C.

[0028] Preferably, the drying time is 12 to 24 hours, such as 12 hours, 13 hours, 14 hours, 15 hours, 16 hours, 17 hours, 18 hours, 19 hours, 20 hours, 21 hours, 22 hours, 23 hours, or 24 hours.

[0029] Preferably, the roasting temperature in step (3) is 400 to 700°C, such as 400°C, 450°C, 500°C, 550°C, 600°C, 650°C or 700°C.

[0030] Preferably, the roasting time in step (3) is 2 to 6 hours, for example, 2 hours, 3 hours, 4 hours, 5 hours or 6 hours.

[0031] As a preferred technical solution of the present invention, the preparation method includes the following steps:

[0032] (1) Mix soluble cerium salt, soluble copper salt and deionized water evenly to obtain a mixed solution containing cerium and copper;

[0033] The soluble cerium salt includes any one or a combination of at least two of cerium nitrate hexahydrate, cerium carbonate, or cerium oxalate; the soluble copper salt includes any one or a combination of at least two of copper nitrate trihydrate, copper carbonate, or copper oxalate; the molar ratio of Ce to Cu in the cerium-copper mixed solution is x:y, where x+y=1, 0.05≤y≤0.55;

[0034] (2) Add the precipitant solution to the cerium and copper mixed solution in step (1) with continuous stirring during the addition process. After mixing evenly, perform hydrothermal reaction at 80-120℃ for 8-16 hours, filter, wash the filtered product until neutral, and dry at 80-120℃ for 12-24 hours to obtain the hydrothermal reaction product.

[0035] The precipitant solution includes any one or a combination of at least two of the following: aqueous sodium hydroxide solution, ammonia solution, or aqueous urea solution.

[0036] (3) The hydrothermal reaction product described in step (2) is calcined at 400-700℃ for 2-6 hours to obtain a non-precious metal composite oxide catalyst.

[0037] Thirdly, the present invention also provides an application of a non-precious metal composite oxide catalyst, wherein the non-precious metal composite oxide catalyst described in the first aspect, or the non-precious metal composite oxide catalyst prepared by the preparation method described in the second aspect, after activity evaluation, is used in an NH3-SCO catalyst to oxidize NH3 to N2 and H2O.

[0038] Preferably, the activity evaluation temperature is 150-300℃, such as 150℃, 160℃, 170℃, 180℃, 190℃, 200℃, 210℃, 220℃, 230℃, 240℃, 250℃, 260℃, 270℃, 280℃, 290℃, or 300℃.

[0039] Compared with the prior art, the present invention has at least the following beneficial effects:

[0040] (1) The non-noble metal composite oxide catalyst of the present invention is Ce x Cu y The O2 catalyst utilizes Cu to enhance the redox ability of the non-precious metal catalyst. The catalyst exhibits an NH3 conversion rate of over 80% at 250°C and an N2 selectivity of over 87% at 200°C. More preferably, the NH3 conversion rate is over 95% at 250°C. Even at temperatures above 250°C, the NH3 conversion rate remains above 95%. Furthermore, the catalyst demonstrates high selectivity for N2 and high stability during the NH3 conversion process.

[0041] (2) The non-noble metal composite oxide catalyst of the present invention has a nanorod morphology, the preparation process is simple, and it is easy to apply industrially. Attached Figure Description

[0042] Figure 1 Ce prepared in Example 1 of this invention 0.7 Cu 0.3 Transmission electron microscopy image of the O2 catalyst;

[0043] Figure 2 This is a transmission electron microscope image of the CeO2 catalyst prepared in Comparative Example 3 of this invention;

[0044] Figure 3 This is a comparison chart of the NH3 conversion rates of the non-noble metal composite oxide catalysts prepared in Examples 1-5 of this invention and the CeO2 catalyst prepared in Comparative Example 3.

[0045] Figure 4 This is a comparison chart of the N2 selectivity of the non-precious metal composite oxide catalysts prepared in Examples 1-5 of the present invention and the CeO2 catalyst prepared in Comparative Example 3. Detailed Implementation

[0046] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, the following examples are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.

[0047] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.

[0048] Example 1

[0049] This embodiment provides a non-noble metal composite oxide catalyst and its preparation method. The non-noble metal composite oxide catalyst is Ce. 0.7 Cu 0.3 The O2 catalyst, the preparation method of which includes the following steps:

[0050] (1) Add 2.422g of cerium nitrate hexahydrate and 0.578g of copper nitrate trihydrate to 30mL of deionized water and dissolve evenly to obtain a mixed solution containing cerium and copper;

[0051] (2) Dissolve 15g of sodium hydroxide in 50mL of deionized water until it is dissolved evenly. Then add it to a mixed solution containing cerium and copper and stir continuously. Then transfer the mixed solution into a reaction vessel and hydrothermally heat it at 100℃ for 12h. Filter the solution and wash the filtered product until it is neutral. Dry it in an oven at 100℃ for 16h to obtain the hydrothermal reaction product.

[0052] (3) The hydrothermal reaction product was calcined in a muffle furnace at 550°C for 4 hours to obtain Ce. 0.7 Cu 0.3 O2 catalyst.

[0053] Figure 1 The Ce prepared in this embodiment is shown. 0.7 Cu 0.3 Transmission electron microscopy (TEM) image of the O2 catalyst shows that the catalyst has an overall nanorod morphology.

[0054] Example 2

[0055] This embodiment provides a non-noble metal composite oxide catalyst and its preparation method. The difference between this embodiment and Embodiment 1 is that the non-noble metal composite oxide catalyst is Ce. 0.6 Cu 0.4 In the preparation method of the O2 catalyst, the mass of cerium nitrate hexahydrate in step (1) is 2.188 g, the mass of copper nitrate trihydrate is 0.812 g, and the rest of the preparation methods and parameters are consistent with those in Example 1.

[0056] Example 3

[0057] This embodiment provides a non-noble metal composite oxide catalyst and its preparation method. The difference between this embodiment and Embodiment 1 is that the non-noble metal composite oxide catalyst is Ce. 0.5 Cu 0.5 In the preparation method of the O2 catalyst, the mass of cerium nitrate hexahydrate in step (1) is 1.928 g, the mass of copper nitrate trihydrate is 1.072 g, and the rest of the preparation methods and parameters are consistent with those in Example 1.

[0058] Example 4

[0059] This embodiment provides a non-noble metal composite oxide catalyst and its preparation method. The difference between this embodiment and Embodiment 1 is that the non-noble metal composite oxide catalyst is Ce. 0.8 Cu 0.2 In the preparation method of the O2 catalyst, the mass of cerium nitrate hexahydrate in step (1) is 2.634 g, the mass of copper nitrate trihydrate is 0.366 g, and the rest of the preparation methods and parameters are consistent with those in Example 1.

[0060] Example 5

[0061] This embodiment provides a non-noble metal composite oxide catalyst and its preparation method. The difference between this embodiment and Embodiment 1 is that the non-noble metal composite oxide catalyst is Ce. 0.9 Cu 0.1 In the preparation method of the O2 catalyst, the mass of cerium nitrate hexahydrate in step (1) is 2.825g and the mass of copper nitrate trihydrate is 0.175g. The rest of the preparation methods and parameters are consistent with those in Example 1.

[0062] Example 6

[0063] This embodiment provides a non-noble metal composite oxide catalyst and its preparation method. The non-noble metal composite oxide catalyst is Ce. 0.45 Cu 0.55 The O2 catalyst, the preparation method of which includes the following steps:

[0064] (1) Add 1.786g of cerium nitrate hexahydrate and 1.214g of copper nitrate trihydrate to 30mL of deionized water and dissolve evenly to obtain a mixed solution containing cerium and copper.

[0065] (2) Dissolve 15g of sodium hydroxide in 50mL of deionized water until it is dissolved evenly. Then add it to a mixed solution containing cerium and copper and stir continuously. Then transfer the mixed solution into a reaction vessel and hydrothermally heat it at 80℃ for 16h. Filter it and wash the filtered product until it is neutral. Dry it in an oven at 120℃ for 12h to obtain the hydrothermal reaction product.

[0066] (3) The hydrothermal reaction product was calcined in a muffle furnace at 400°C for 6 hours to obtain Ce. 0.45 Cu 0.55 O2 catalyst.

[0067] Example 7

[0068] This embodiment provides a non-noble metal composite oxide catalyst and its preparation method. The non-noble metal composite oxide catalyst is Ce. 0.95 Cu 0.05 The O2 catalyst, the preparation method of which includes the following steps:

[0069] (1) Add 2.915g of cerium nitrate hexahydrate and 0.085g of copper nitrate trihydrate to 30mL of deionized water and dissolve evenly to obtain a mixed solution containing cerium and copper;

[0070] (2) Dissolve 15g of sodium hydroxide in 50mL of deionized water until it is dissolved evenly. Then add it to a mixed solution containing cerium and copper and stir continuously. Then transfer the mixed solution into a reaction vessel and hydrothermally heat it at 120℃ for 8h. Filter it and wash the filtered product until it is neutral. Dry it in an oven at 80℃ for 24h to obtain the hydrothermal reaction product.

[0071] (3) The hydrothermal reaction product was calcined in a muffle furnace at 700°C for 2 hours to obtain Ce. 0.95 Cu 0.05 O2 catalyst.

[0072] Example 8

[0073] This embodiment provides a non-precious metal composite oxide catalyst and its preparation method. The difference between this embodiment and Example 1 is that in the preparation method, the hydrothermal reaction temperature in step (2) is 60°C, and the rest of the preparation methods and parameters are consistent with Example 1.

[0074] Example 9

[0075] This embodiment provides a non-precious metal composite oxide catalyst and its preparation method. The difference between this embodiment and Example 1 is that in the preparation method, the hydrothermal reaction temperature in step (2) is 140°C, and the rest of the preparation methods and parameters are consistent with Example 1.

[0076] Example 10

[0077] This embodiment provides a non-precious metal composite oxide catalyst and its preparation method. The difference between this embodiment and Example 1 is that in the preparation method, the calcination temperature in step (3) is 350°C, and the rest of the preparation methods and parameters are consistent with those in Example 1.

[0078] Example 11

[0079] This embodiment provides a non-precious metal composite oxide catalyst and its preparation method. The difference between this embodiment and Example 1 is that in the preparation method, the calcination temperature in step (2) is 750°C, and the rest of the preparation methods and parameters are consistent with those in Example 1.

[0080] Comparative Example 1

[0081] This comparative example provides a non-noble metal composite oxide catalyst and its preparation method. The difference between this comparative example and Example 1 is that the non-noble metal composite oxide catalyst is Ce. 0.98 Cu 0.02 In the preparation method of the O2 catalyst, the mass of cerium nitrate hexahydrate in step (1) is 2.966 g, the mass of copper nitrate trihydrate is 0.034 g, and the rest of the preparation methods and parameters are consistent with those in Example 1.

[0082] Comparative Example 2

[0083] This comparative example provides a non-noble metal composite oxide catalyst and its preparation method. The difference between this comparative example and Example 1 is that the non-noble metal composite oxide catalyst is Ce. 0.4 Cu 0.6 In the preparation method of the O2 catalyst, the mass of cerium nitrate hexahydrate in step (1) is 1.635g and the mass of copper nitrate trihydrate is 1.365g. The rest of the preparation methods and parameters are consistent with those in Example 1.

[0084] Comparative Example 3

[0085] This comparative example provides a CeO2 catalyst and its preparation method. The difference between this comparative example and Example 1 is that in the preparation method, only 3g of cerium nitrate hexahydrate is added in step (1), and copper nitrate trihydrate is not added. The rest of the preparation methods and parameters are consistent with those of Example 1.

[0086] Figure 2 The transmission electron microscope (TEM) image of the CeO2 catalyst prepared in this comparative example is shown. As can be seen from the figure, the CeO2 catalyst has a nanorod morphology.

[0087] Test methods

[0088] Ce prepared in Examples 1-11 and Comparative Examples 1-2 x Cu yThe catalyst activity of the O2 catalyst and the CeO2 catalyst prepared in Comparative Example 3 was evaluated. The specific catalyst activity evaluation method was as follows: 100 mg of catalyst was ground and sieved to obtain catalyst particles of 40–60 mesh, which were then tested. The test was conducted in a fixed-bed reactor. The simulated flue gas composition was: 500 ppm NH3, 10% O2, with N2 as the balance gas; the total flow rate of the simulated flue gas was 200 mL / min, and the reaction space velocity was 120,000 mL·h. -1 ·g -1 The results of the catalyst activity test are shown in Table 1.

[0089] Figure 3 The graph shows a comparison of the NH3 conversion rates of the non-noble metal composite oxide catalysts prepared in Examples 1-5 and the CeO2 catalyst provided in Comparative Example 3. It can be seen from the graph that, under the same reaction conditions, CeO2 catalysts significantly increase NH3 conversion rates. x Cu y The low-temperature NH3 conversion activity of the O2 catalyst was higher than that of the CeO2 catalyst alone, indicating that Cu modification can effectively promote the improvement of the catalyst's low-temperature activity, and Ce... x Cu y In O2 catalysts, the Cu content also affects the catalytic performance of the resulting catalyst.

[0090] Figure 4 The figure shows a comparison of the N2 selectivity of the non-noble metal composite oxide catalysts prepared in Examples 1-5 and the CeO2 catalyst provided in Comparative Example 3. It can be seen from the figure that, under the same reaction conditions, CeO2... x Cu y The N2 selectivity of the O2 catalyst was higher than that of the CeO2 catalyst alone, indicating that Cu modification can effectively promote the improvement of N2 selectivity at low temperatures, and CeO2 catalyst... x Cu y In O2 catalysts, the Cu content also affects the N2 selectivity of the resulting catalyst.

[0091] Table 1

[0092]

[0093] The test results show that:

[0094] (1) Ce provided by the present invention x Cu yThe O2 catalyst exhibits excellent low-temperature NH3 conversion activity and good N2 selectivity. Combined with the preparation method provided in this invention, the prepared catalyst achieves an NH3 conversion rate of over 80% at 250℃ and an N2 selectivity of over 87% at 200℃. More preferably, the NH3 conversion rate is over 95% at 250℃. When y is 0.3, Ce... 0.7 Cu 0.3 The O2 catalyst exhibits the best activity for NH3 conversion at low temperatures, with a conversion rate as high as 99.76% at 250℃ and an N2 selectivity of 87.34% at 200℃.

[0095] (2) As can be seen from Examples 8 to 9, if the temperature of the hydrothermal reaction is too high, the pore structure of the prepared catalyst will be destroyed, thereby reducing the specific surface area of ​​the catalyst and resulting in a decrease in the NH3 conversion rate; if the temperature of the hydrothermal reaction is too low, the catalyst will not be fully crystallized, resulting in a significant decrease in the NH3 conversion rate and a decrease in the N2 selectivity.

[0096] (3) As can be seen from Examples 10-11, if the calcination temperature is too high, the catalyst nanorod structure will be destroyed due to the high temperature, and the catalyst performance will not be effectively improved, resulting in a significant decrease in NH3 conversion rate and N2 selectivity; if the calcination temperature is too low, the catalyst will not form the target nanorod structure, resulting in a decrease in NH3 conversion rate.

[0097] (4) As can be seen from Example 1 and Comparative Examples 1-2, when the value of y is too high or too low, it will affect Ce. x Cu y O2 catalyst performance. If the y value is too high, that is, the Cu content is too high, it will block the surface active sites, which will not only fail to further improve the catalyst performance, but will instead lead to a decrease in the NH3 conversion rate of the catalyst; if the y value is too low, that is, the Cu content is too low, the number of active sites will decrease, and it will not be able to increase the oxygen vacancies, resulting in a decrease in the NH3 conversion rate and N2 selectivity of the catalyst.

[0098] (5) As can be seen from Example 1 and Comparative Example 3, when CeO2 without oxidation is used as a catalyst, it has few active sites and poor oxidation ability. The corresponding NH3 conversion rate is only 1.16% at 250℃ and there is no selectivity for N2 at 200℃.

[0099] In summary, this invention utilizes Cu to enhance the redox ability of the non-precious metal catalyst. The catalyst exhibits an NH3 conversion rate exceeding 80% at 250°C and an N2 selectivity exceeding 87% at 200°C. More preferably, the NH3 conversion rate exceeds 95% at 250°C. Even at temperatures above 250°C, the NH3 conversion rate remains above 95%. Furthermore, the non-precious metal composite oxide catalyst demonstrates high selectivity for N2 during the NH3 conversion process, meeting current market application requirements.

[0100] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. The use of a non-precious metal composite oxide catalyst, characterized in that, After activity evaluation, the catalyst was used in the NH3-SCO catalyst to oxidize NH3 to N2 and H2O. The non-noble metal composite oxide catalyst is Ce. 0.7 Cu 0.3 O2 catalyst; The Ce 0.7 Cu 0.3 The O2 catalyst has a nanorod morphology; The preparation method of the non-noble metal composite oxide catalyst includes the following steps: (1) Mix soluble cerium salt, soluble copper salt and deionized water evenly to obtain a mixed solution containing cerium and copper; The soluble cerium salt includes cerium nitrate hexahydrate; the soluble copper salt includes any one or a combination of at least two of copper nitrate trihydrate, copper carbonate, or copper oxalate; and the molar ratio of Ce to Cu in the cerium-copper mixed solution is 7:

3. (2) Add the precipitant solution to the cerium and copper mixed solution in step (1), and stir continuously during the addition process. After mixing evenly, perform hydrothermal reaction at 80~120℃ for 8~16h, filter, wash the filtered product until neutral, and dry at 80~120℃ for 12~24h to obtain the hydrothermal reaction product. The precipitant solution includes any one or a combination of at least two of the following: aqueous sodium hydroxide solution, ammonia solution, or aqueous urea solution; (3) The hydrothermal reaction product described in step (2) is calcined at 400~700℃ for 2~6h to obtain a non-precious metal composite oxide catalyst.

2. The use of the non-precious metal composite oxide catalyst according to claim 1, characterized in that, The activity evaluation temperature is 150~300℃.

Images