WO2018150284A1

WO2018150284A1 - Precious metal catalyst loaded by metal oxide, preparation method, and uses

Info

Publication number: WO2018150284A1
Application number: PCT/IB2018/050604
Authority: WO
Inventors: 孙予罕; 祝艳; 杨娜婷
Original assignee: 能源技术研究所
Priority date: 2017-02-17
Filing date: 2018-01-31
Publication date: 2018-08-23
Also published as: CN108452797A; CN108452797B

Abstract

The present invention provides a precious metal catalyst loaded by a metal oxide, a preparation method, and applications. The precious metal catalyst comprises the following components: a precious metal, an oxide of the precious metal, and a metal oxide. In the precious metal catalyst loaded by a metal oxide, the ratio of the mass of the precious metal to the total mass of the precious metal and the metal oxide is -1 to 10:100, and the precious metal catalyst loaded by a metal oxide is of a two-dimensional structure. The preparation method in the present invention is easy to operate, the prepared catalyst has uniform morphology and good stability; and when the catalyst is applied in a methane combustion reaction, the conversion rate of methane reaches 100% when the reaction temperature of C¾ below 400ºC, and a good low-temperature oxidization activity of the methane is provided. In addition, the precious metal catalyst loaded by a metal oxide has the advantages of good stability, a long service life, good water resistance and the like, and has no obvious deactivation phenomenon at the temperature ranging from 310ºC to 500ºC for 100 hours, and has a good industrial application prospect.

Description

Metal oxide supported noble metal catalyst, preparation method and use thereof

The invention belongs to the field of chemical synthesis, and in particular relates to a metal oxide supported noble metal catalyst, a preparation method and use thereof. Background technique

Due to the declining world oil reserves, more and more research has focused on the development of alternative energy sources, and abundant natural gas energy has become the most promising source of energy in the 21st century. However, methane, as a major component of sulphur gas, is synthesized not only as a by-product in some industrial synthesis processes, but also as a major hydrocarbon air pollutant in natural gas fuel vehicles and natural gas power plants. Its greenhouse effect is C0 ₂ 21 times. At present, most of the formazan-burning catalysts studied require a CH bond cleavage at a higher temperature (>40 (TC)), and this temperature cannot satisfy the required temperature of the lean-burn engine exhaust.

Precious metal supported catalysts exhibit good activity for the low temperature combustion reaction of formazan, but such catalysts do not have good stability at high temperatures, and precious metals are prone to loss and sintering at higher temperatures, resulting in a decrease in catalyst activity. Carrying precious metals by conventional impregnation methods does not solve these problems well because the method generally lacks the interaction between precious metals and carriers. Transition metal oxides C CU, NiO and their composites have good properties in many catalytic reactions, such as methane oxidation, CO oxygen and ^3 reduction reactions. Pd is encapsulated in comparison to conventional supported Pd catalysts. The carrier can show good stability and high catalytic activity. Therefore, the exploration of novel structure of noble metal supported cobalt tetraoxide catalyst has a breakthrough significance for the development of low temperature oxidation of methane.

At present, in the field of catalysis, the catalyst is highly dispersed on a carrier by a method such as light irradiation, precipitation deposition, impregnation, atomic deposition, etc., and the obtained catalyst exhibits strong metal and carrier force, making the catalyst catalytically active and more. Good resistance to sintering. Based on the above, it is necessary to provide a gentle and simple method for synthesizing a noble metal nanocatalyst loaded with a two-dimensional structure metal oxide. Summary of the invention

In view of the disadvantages of the prior art described above, it is an object of the present invention to provide a metal oxide supported noble metal catalyst, a preparation method and use thereof to achieve a gentle and simple preparation of a two-dimensional metal oxide supported noble metal nanocatalyst. Synthetic method.

To achieve the above and other related objects, the present invention provides a metal oxide supported noble metal catalyst comprising the following components: a noble metal, an oxide of a noble metal, and a metal oxide, the metal oxide supported noble metal catalyst The ratio of the mass of the noble metal to the total mass of the noble metal and the metal oxide is 1 to 10:100, and the metal oxide-supported noble metal catalyst has a two-dimensional structure.

As a preferred embodiment of the metal oxide-supported noble metal catalyst of the present invention, the metal oxide-supported noble metal catalyst is a nanosheet, and the ratio of the maximum radial length thickness of the nanosheet is not less than 10.

As a preferred embodiment of the metal oxide-supported noble metal catalyst of the present invention, the metal of the metal oxide is selected from one or a combination of two of Co and Ni.

Preferably, when the metal of the metal oxide is a combination of Co and Ni, wherein the ratio of Ni to Co is 1:2. As a preferred embodiment of the metal oxide supported noble metal catalyst of the present invention, the noble metal is selected from one or a combination of two of Pd and Au.

Preferably, when the precious metal element is a combination of Pd and Au, wherein the mass ratio of Pd to Au is 1: 10-10:

1.

The invention also provides a preparation method of a metal oxide supported noble metal catalyst, wherein a metal salt is co-dissolved with an alkaline surfactant in a glycol system, and the two-dimensional metal precursor is obtained by hydrothermal, centrifugal separation and drying. The two-dimensional metal precursor is dispersed in a solution, and the noble metal salt solution is added according to the composition ratio of the catalyst, and the metal oxide-supported noble metal catalyst is obtained by light, centrifugal washing, drying and calcination.

As a method for preparing a metal oxide supported noble metal catalyst of the present invention, the method comprises the following steps: Step 1), dispersing a metal salt and an alkaline surfactant in a glycol, and hydrothermally , centrifugally separating, drying to obtain a two-dimensional metal precursor; step 2), dispersing the two-dimensional metal precursor in a solution, adding a precious metal salt solution according to a composition ratio of the catalyst, and dispersing the precious metal in the light by using a xenon lamp On the virgin metal precursor; step 3), the dispersion solution obtained in the step 2) is subjected to centrifugation, drying and calcination to obtain a metal oxide-supported noble metal catalyst.

As a preferred embodiment of the method for producing a metal oxide-supported noble metal catalyst of the present invention, the ratio of the metal salt, the basic surfactant to the glycol is 0.5-10 mmol: 0.5-5 mmol: 75 mL.

As a preferred embodiment of the method for producing a metal oxide-supported noble metal catalyst of the present invention, the glycol is used as a solvent and a chelating agent in the reaction, and is selected from one or a combination of ethylene glycol and diethylene glycol.

As a preferred embodiment of the method for preparing a metal oxide supported metal catalyst of the present invention, the alkaline surfactant is selected from polyvinylpyrrolidone of different molecular weight, and the molecular weight thereof comprises 10000 g mol, 24000 g/moK. And one or a combination of two or more of 48000 g/mol.

As a preferred embodiment of the method for preparing a metal oxide supported noble metal catalyst of the present invention, the hydrothermal reaction temperature of the two-dimensional metal precursor is 170-200'C, and the hydrothermal reaction time of the two-dimensional metal precursor is 12~ 48 h.

A preferred embodiment of the method for preparing a metal oxide supported noble metal catalyst of the present invention, the metal salt The concentration is 0.004-0.009 mol/L.

As a preferred embodiment of the method for producing a metal oxide-supported noble metal catalyst of the present invention, the noble metal salt includes one or a combination of a palladium salt and a gold salt.

As a preferred embodiment of the method for producing a metal oxide-supported noble metal catalyst of the present invention, the noble metal salt is selected from one or a combination of palladium nitrate and gold chloride.

As a preferred embodiment of the method for preparing a metal oxide supported noble metal catalyst of the present invention, the light has a corresponding power density of 50 to 150 mW/cm ² at a wavelength of 365 nm.

As a preferred embodiment of the method for preparing a metal oxide-supported noble metal catalyst of the present invention, the calcination temperature is 300 to 45 (TC, and the calcination time is 1 to 5 hours.

The invention also provides the use of a metal oxide supported noble metal catalyst for the catalytic combustion of methane. As a preferred embodiment of the use of the metal oxide supported noble metal catalyst of the present invention, the methane catalytic combustion reaction conditions are: a reaction temperature of 200 to 450 'C, a reaction pressure of normal pressure; and a total flow rate of the reaction of 50 to 100 mL /min, the reaction gas includes C3⁄4, 0 ₂ and N ₂ , the flow ratio of C3⁄4, 0 ₂ and N ₂ is 1:5~15:84~94, and the space velocity is 10000~120000 mL/(g-h). The mesh number of the catalyst is 60-80 mesh.

Preferably, the reaction temperature for complete conversion of formazan is 300~40 (TC)

As described above, the metal oxide-supported noble metal catalyst of the present invention, the preparation method and use thereof have the following beneficial effects:

The invention adopts the hydrothermal synthesis method and the light irradiation method to prepare the metal oxide supported noble metal catalyst, the preparation method is simple and easy to operate, and the prepared catalyst has uniform morphology and good stability, and can be applied to the methane catalytic combustion reaction. When the reaction temperature is below 400 ,, the methane conversion rate can be as high as 100%, and it has a good low temperature oxidation activity of formazan. At the same time, the metal oxide supported noble metal catalyst has the advantages of good stability, long life, good water resistance, etc., and continuous operation for more than 100 hours at 310~500 'C has no obvious phenomenon, and has good industrial application prospect. DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a flow chart showing the steps of a method for preparing a metal oxide supported noble metal catalyst of the present invention. Figure 2a is an SEM image of the catalyst precursor prepared in Example 1.

Figure 2b is an SEM image of the calcined metal oxide supported noble metal catalyst prepared in Example 1.

Figure 3 shows the XRD pattern of the metal oxide supported noble metal catalyst prepared in Example 1.

4 is a graph showing the results of catalytic methane combustion reaction of the metal oxide-supported noble metal catalyst prepared in Example 1. Figure 5 shows that the metal oxide supported noble metal catalyst prepared in Example 1 catalyzes the heat stability of the combustion reaction of formazan. Sexual results map.

Figures 6a and 6b show TEM, HRTEM images of the metal oxide supported noble metal catalyst prepared in Example 10.

Figure 7 shows an XRD pattern of the metal halide supported noble metal catalyst prepared in Example 10.

Fig. 8 is a graph showing the combustion reaction of a metal oxide-supported noble metal catalyst prepared in Example 10 for catalytic combustion. Component label description

S11-S13 Step 1) ~ Step 3) Detailed implementation

The embodiments of the present invention are described below by way of specific specific examples, and those skilled in the art can readily understand other advantages and effects of the present invention from the disclosure of the present disclosure. The invention may be practiced or applied in various other specific embodiments, and various modifications and changes can be made without departing from the spirit and scope of the invention.

Please refer to the picture] ~ Figure 8. It should be noted that the illustrations provided in the present embodiment merely illustrate the basic concept of the present invention in a schematic manner, and only the components related to the present invention are shown in the drawings, instead of the number of components in actual implementation, The shape and size of the drawing, the actual implementation of each component's type, number and proportion can be a random change, and its component layout can be more complicated.

The present embodiment provides a metal oxide supported noble metal catalyst comprising the following components: a noble metal, an oxide of a noble metal, and a metal oxide, the precious metal of the metal oxide supported noble metal, a noble metal and a metal oxide The ratio of the total mass S is 1 to 10:100, and the noble metal oxide-supported noble metal catalyst has a two-dimensional structure. The ratio of the mass of the precious metal to the total mass of the precious metal and the metal oxide may be 1 to 3 _: 100, 3 to 5 _: 100, 5 to 10: 100, etc., the noble metal and the noble metal oxide are nanoparticles, and the particle size is <6 mn.

As an example, the metal oxide supported noble metal catalyst is a nanosheet having a ratio of a maximum radial length to a thickness of the nanosheet of not less than 10. .

As an example, the metal of the metal oxide is selected from one or a combination of two of Co, Ni. Preferably, when the metal of the metal oxide is a combination of Co and M, wherein the ratio of i to Co is 1:2.

As an example, the noble metal is selected from the group consisting of Pd, Au or a combination of two. Preferably, when the noble metal element is a combination of Pd and Au, wherein the mass ratio of Pd to Au is 1: 10-10:1. For example, the mass ratio of Pd to Au can be 1: 10~1: 5, 1: 5-1: 3, 1: 3-1: 1, 1: 1-3: 1, 3: 1-5: 1. 5 : 10: 1 and so on.

This embodiment also provides a method for preparing a metal oxide supported noble metal catalyst, in a system of glycols, The metal salt is co-dissolved with the alkaline surfactant, and is hydrothermally, centrifugally separated and dried to obtain a two-dimensional metal precursor; the two-dimensional metal precursor is dispersed in the solution, and the precious metal salt solution is added according to the composition ratio of the catalyst. The metal oxide supported precious metal catalyst is obtained by light, centrifugal washing, drying and calcination.

As shown in FIG. 1, the preparation method of the metal oxide-supported noble metal catalyst of the present embodiment includes the following steps: as shown in FIG. 1, first, step 1) S11 is carried out, and the metal salt and the alkaline surfactant are dispersed in two. In the alcohol, a two-dimensional metal precursor is obtained by hydrothermal, centrifugal separation and drying.

As an example, the ratio of the metal salt, the basic surfactant and the glycol is 0.5 to 10 mmol: 0.5-5 mmol: 75 mL. For example, the ratio of metal salt to alkaline surfactant can be 0.5~lmoh 0.5-5 nuno l~5mol: 0.5-5 mmol, 5~! 0 mmol: 0.5-5 mmol; the ratio of metal salt to glycol may be 0.5~1 mmol: 75 mL, 1-5 mmol: 75 mL or 5-10 mmol: 75 mL. A further preferred ratio of metal salt, alkaline surfactant and glycol is 7.5 mmol: 1.3 mmol: 75 mL.

As an example, the glycol is used as a solvent and a chelating agent in the reaction, and is selected from one or a combination of ethylene glycol and diethylene glycol.

As an example, the alkaline surfactant is selected from the group consisting of different molecules: polyvinylpyrrolidone, and its molecular weight includes one or a combination of two or more of 10000 g/mol, 24000 g/moK and 48000 g/mol.

As an example, the hydrothermal reaction temperature of the two-dimensional metal precursor is 170 to 200 Ό, and the hydrothermal reaction time of the two-dimensional metal precursor is 12 to 8 h. For example, the M degree of the hydrothermal reaction may be, for example, 170 to 180 ° C, 180 to 190 ° C or 190 to 200 ° C, etc., and the diurnal temperature of the hydrothermal reaction is 12 to 48 h, such as 12 to 24 h or 24 to 48 h. . A still more preferred reaction temperature is 180 'C and the reaction time is 12 h.

As an example, the concentration of the metal salt is 0.004 0.009 mol/L.

As shown in FIG. 1, then step 2) S12 is performed, the two-dimensional metal precursor is dispersed in a solution, a precious metal salt solution is added according to the composition ratio of the catalyst, and the noble metal is dispersed in the two-dimensional metal precursor by using a xenon lamp illumination. on.

As an example, the noble metal salt includes one or a combination of a noble metal nitrate and a noble metal chloride. Preferably, the noble metal salt is selected from one or a combination of palladium nitrate and gold chloride.

As an example, the illumination has a corresponding 'power density of 50 to 150 mW/cm ² at a wavelength of 365 nm. A more preferred power density at a wavelength of 365 nm is 50 mW/cm ² . '

As shown in Fig. 1, finally, steps 3) to S13 are carried out, and the dispersion solution obtained in the step 2) S12 is subjected to centrifugal separation, drying and calcination to obtain a metal oxide-supported noble metal catalyst.

As an example, the calcination temperature is 300 to 45 (TC, and the calcination time is 1 to 5 hours. For example, the calcination temperature may be 300-350 350 to 400 ° C or 400 to 450 ° C, and the calcination time is 1-5. Hours, such as 1-3 h, 3-4 h or 4~5 h. Further more preferably, the calcination temperature is 350 V and the calcination time is 4 h. More preferably, the calcination rate is from 1 to ⁵⁰ C/min.

This example also provides the use of a metal oxide supported noble gold catalyst for the formazan catalytic combustion reaction. As an example, the catalytic combustion reaction conditions of formazan are: reaction temperature is 200~450Ό, reaction pressure is normal pressure; total reaction flow rate is 50~100 mL/min, and the reaction gas includes C, 0 ₂ and N ₂ , C , The flow ratio of 0 ₂ and N ₂ is 1:5-15:84-94, the space velocity is 10000~120000 mL/(g-h), and the mesh number of the catalyst is 60-80 mesh. For example, the flow ratio of C and 0 ₂ may be 1:5~10 or 1:10~15, and the flow ratio of CH ₄ and N ₂ may be 1:84~89 or 1:89~94; the airspeed may be 10000 ~20000 mL/(g-h), 20000~30000 mL/(g-h), 30000~60000 mL/(g-h), or 60000~120,000 mU(g'h). Preferably, the flow ratio of C, 0 ₂ and N ₂ is 1:10:89.

Preferably, the reaction temperature is from 300 to 400 °C. The metal oxide supported noble metal catalyst of the invention has high activity and thermal stability, can completely convert methane at 40 CTC, and has relatively stable thermal stability in a stable range of 310 to 500 Torr. Example 1

This embodiment provides a preparation method of a 3% Pd-Co ₃ 0 nanosheet (3% refers to the ratio of the total mass of the noble metal element of the noble metal element and the metal oxide, and the phase of the following embodiment defines the same), including the steps. : Weigh 7.5 mmol of cobalt acetate tetrahydrate (Co(C COO) ₂ '4H ₂ 0) and 1.3 ₁₀ 0101 ?¥卩(1\/1\^24000) dissolved in 75 1 ₁ ^ ethylene glycol, stir and dissolve After transfer to a high pressure reaction kettle, the water was heated at 180 ° C for 12 h, cooled to room temperature, centrifuged with deionized water, washed, and dried under vacuum at 60 ° C for 12 h to obtain hydroxyethyl cobalt nanosheets. The SEM image is shown in Figure 2a. Disperse the hydroxyethyl ruthenium cobalt nanosheet in water to obtain a dispersion system of hydroxyethyl cobalt U9 mM, 30 mL), and add 5 mL of a 8.8 mg Pd(N0 ₃ ) ₂ solution, and then place the dispersion in a xenon lamp (6A, The intensity of light intensity at 365 nm is 50 mW/cm ² )>\ Room temperature for 15 min. The Pd-hydroxyethyl cobalt obtained by the reaction was centrifuged, dried, and calcined at 350 Torr for 3 h to obtain 3% Pd- 0) ₃ 0 ₄ nm tablets. The 3% Pd-Co ₃ 0 ₄ nanosheets were ground into fine powder, extruded in a mold under a pressure of 40 kN, and crushed and sieved to obtain catalyst particles having a particle size of 60-80 mesh. The SEM image is shown in 2b. The XRD is shown in Figure 3. The catalytic reaction conditions are: the temperature of the catalytic reaction is 200~450 V, the pressure is normal pressure; the total flow of the reaction is 50 mL/min, wherein the flow ratio of the three gases is C:O ₂ :N ₂ =l :10 :89; The space velocity is 30000 mL/(g-h), 'The reaction results are shown in Table 1 and Figure 4-5. Example 2

This embodiment provides a method for preparing 1% Pd-Co ₃ (3⁄4 nanosheet), comprising the steps of: weighing 10 mmol of cobalt acetate tetrahydrate (Co(C3⁄4COO) ₂ '4H ₂ 0) and 2 mmol PVP (Mw=48000) Dissolved in 75 mL of ethylene glycol, stirred and dissolved Transfer to a high pressure reactor, heat at 120 ° C for 12'h, cool to room temperature, centrifuge with deionized water, and wash at 60. Drying under vacuum for 12 h at C gave hydroxyethyl cobalt nanosheets. The hydroxyethyl cobalt nanosheet was dispersed in water to obtain a dispersion of hydroxyethyl cobalt (39 mM, 30 mL), and 5 _{m of} a 2.9 mg Pd(N0 ₃ ) ₂ solution was added, and then the dispersion was placed in a xenon lamp ( 10A, the light intensity density at 365 nm is 100 m\V/cm ² ), and the room temperature is irradiated for 5 min. The Pd-hydroxyethyl cobalt obtained by the reaction was centrifuged, dried, and calcined at 350 Torr for 5 hours to obtain 1% Pd-Co ₃ 0. nanosheet. The 1% Pd-Co ₃ 0 ₄ nanosheet was ground into a fine powder, extruded in a mold under a pressure of 40 kN, and subjected to crushing and sieving to obtain catalyst particles having a particle diameter of 60 to 80 mesh. The catalytic reaction conditions are: the temperature of the catalytic reaction is 200~450 Ό, the pressure is normal pressure; the total flow rate of the reaction is 50 mL/min, wherein the flow rates of the three gases are CH ₄ 0 ₂ :Nr-1 :10:89 The space velocity is 10000 mL/(g'h), and the reaction results are shown in Table 1. Example 3

This embodiment provides a method for preparing a 10% Pd-Co ₃ 0 ₄ nanosheet, comprising the steps of: weighing 2.5 mmol of cobalt acetate tetrahydrate (Co(CH ₃ COO) ₂ '43⁄40) and 5 mmol PVP (Mw=10000) Dissolve in 75 mL of ethylene glycol, stir and dissolve, transfer to a pressure reactor, heat at 180 °C for 24 h, cool to room temperature, centrifuge with deionized water, and wash at 60. Drying under vacuum for 12 h at C gave hydroxyethyl cobalt nanosheets. Disperse the hydroxyethyl cobalt nanosheet in water to obtain a dispersion of hydroxyethyl cobalt (39 mM, 30 mL), add 5 mL of 31.6 mg Pd(N0 ₃ ) ₂ , and then place the dispersion on the xenon lamp (6A). , the light intensity at 365 nm is 50 mW/cm ² ), and the room temperature is irradiated for 15 min. The Pd-hydroxyethyl cobalt obtained by the reaction was centrifuged, dried, and calcined at 350 Torr for 3 h to obtain 10% Pd-Co; nanosheet. The 10% Pd-Co ₃ 0 ₄ nanosheet was ground into a fine powder, extruded in a mold under a pressure of 40 kN, and crushed and sieved to obtain catalyst particles having a particle diameter of 60 to 80 mesh. The catalytic reaction conditions are as follows: The temperature of the catalytic reaction is 200 to 45 (TC, the pressure is normal pressure; the total flow rate of the reaction is 50 mL/min, wherein the flow ratio of the three gases is C:O ₂ :N ₂ =l:10 : 89 _{; the} space velocity is 120000 mL / (g - h), the reaction results are shown in Table 1. Example 4

The present embodiment provides a method for preparing a 3% Au-Co ₃ 0 nanosheet, comprising the steps of: weighing 7.5 mmol of cobalt acetate tetrahydrate (Co(CH ₃ COO) ₂ '40 ) and 5 mmol PVP (Mw= 48000) Dissolved in 75 mL of diethylene glycol, stirred and dissolved, transferred to a pressure reactor, heated at 200 °C for 12'h, cooled to room temperature, centrifuged with deionized water, washed, at 60 Ό Dry under vacuum for 12 h to obtain hydroxyethyl cobalt nanosheets. Disperse the hydroxyethyl cobalt nanosheets in water to obtain a dispersion of hydroxyethyl diamond (39 mM, 30 mL), and add 5 mL of 0.0044 g of AuC3⁄4 aqueous solution, after which The dispersion was placed in a xenon lamp (6A, light intensity at 365 nm, 50 mW/n ² ), and irradiated at room temperature for 15 min. The Au-hydroxyethyl group obtained by the reaction. T IB2018/050604

Cobalt was separated by centrifugation, dried, and calcined at 350 Torr for 3.h to obtain 3% Au-Co ₃ 0, nanosheet. The 3% Au-Co ₃ 0 ₄ nanosheet was ground into a fine powder, extruded in a mold under a pressure of 40 kN, and crushed and sieved to obtain a catalyst particle having a particle diameter of 60 〜. The catalytic reaction conditions are: the temperature of the catalytic reaction is 200~450 Ό, the pressure is normal pressure; the total flow rate of the reaction is 50 mL/min, wherein the flow ratio of the three gases is C:O _{2 :} N ₂ =l : 10: 89 _; space velocity is 20000 mL / (g-h), the reaction results are shown in Table 1. Example 5

This embodiment provides a method for preparing a /o Au-CosOd nanosheet, comprising the steps of: weighing 7.5 mmol of cobalt acetate tetrahydrate (Co(CH ₃ COO) ₂ '4H ₂ 0) and 3 mmol of PVP (Mjv=24000) Dissolved in 75 mL of ethylene glycol, stirred and dissolved, transferred to a high pressure reaction kettle, heated at 200 ° C for 24 h, cooled at room temperature, centrifuged with deionized water, washed, and dried under vacuum at 60 ° C. 12 h, hydroxyethyl cobalt nanosheets were obtained. The hydroxyethyl cobalt nanosheet was dispersed in water to obtain a dispersion of hydroxyethyl cobalt (39 mM, 30 mL), and 5 mL of an aqueous solution of 0.0015 g of AuCl _{3 was} added, and then the dispersion was placed in a xenon lamp (15 A, 365 nm). The light intensity was 150 mW/cm ² ) and the room temperature was irradiated for 15 min. The Au-hydroxyethyl cobalt obtained by the reaction was centrifuged, dried, and calcined at 350 ° C for 3 h to obtain a %Au-Co ₃ 0 ₄ nanosheet. The 1% Au-Co ₃ 0 ₄ nanosheet was ground into a fine powder, extruded in a mold under a pressure of 40 kN, and crushed and sieved to obtain catalyst particles having a particle diameter of 60 to 80 mesh. The catalytic reaction conditions are: the temperature of the catalytic reaction is 200~450 'C, the pressure is normal pressure; the total flow rate of the reaction is 50 mL/min, and the flow rate ratio of the three gases is C:0 _2: N ₂ =1 : 10 :89; The space velocity is 10000 mL/(g-h), and the reaction results are shown in Table 1. Example 6

This embodiment provides a method for preparing a 10% Au-Co ₃ 0 ₄ nanosheet, comprising the steps of: weighing 0J5 mmol of cobalt acetate tetrahydrate (Co(C3⁄4COO) ₂ '4H ₂ 0) and 2.5 mmol PVP (Mw=48000) Dissolved in 75 mL of ethylene glycol, stirred and dissolved, transferred to a pressure reactor, heated at 180 °C for 48 h, cooled to room temperature, centrifuged with deionized water, washed, and dried under vacuum at 60 Torr. 12 h, hydroxyethyl cobalt nanosheets were obtained. The hydroxyethyl cobalt nanosheet was dispersed in water to obtain a dispersion of hydroxyethyl cobalt (39 mM, 30 mL), and 5 mL of 0.0150 g of AuCl ₃ aqueous solution was added, and then the dispersion was placed in a Millennium lamp (6 A, 365 nm). The light intensity was 50 mW/cm ² ) and the room temperature was irradiated for 15 min. The Au-hydroxyethyl cobalt obtained by the reaction was centrifuged, dried, and calcined at 450 Torr for 3 h to obtain 10% Au-Co ₃ 0 ₄ nanosheet. The 10% Au-Co _} 0, nanosheet was ground into a fine powder, extruded in a mold under a pressure of 40 kN, and crushed and sieved to obtain catalyst particles having a particle diameter of 60 to 80. The catalytic reaction conditions are as follows: the temperature of the catalytic reaction is 200~450 'C, the pressure is normal pressure; the total flow rate of the reaction is 50 mL/min, and the flow rate ratio of the three gases is C:0 ₂ :N ₂ =1 : 10 :89; airspeed is 60000 mL/(g-h), anti The results should be shown in Table 1. Example 7

This embodiment provides a 3°/. Preparation method of PdAu(5:l)-C03O4 nanosheet, including steps: Weigh 7.5 mmol of cobalt acetate tetrahydrate (Co(CH ₃ COO) ₂ '43⁄40) and 1.5 ₀ ^101?¥卩(1^24000) In 75 ₁ 1 ^ ethylene glycol, stirred and dissolved, transferred to a high pressure reactor, heated at 180 ° C for 12 h, cooled to room temperature, centrifuged with deionized water, washed, and dried under vacuum at 60 Torr. 12 h, hydroxyethyl cobalt nanosheets were obtained. The hydroxyethyl cobalt nanosheet was dispersed in water to obtain a dispersion of hydroxyethyl cobalt (78 mM, 30 mL), and 5 mL of a mixed aqueous solution of 0.0147 g of Pd(N0 ₃ ) and 0.0015 g of AuCl _{3 was added to the} aqueous solution, and then the dispersion was added. The lamp was placed at room temperature for 15 minutes under a xenon lamp (6A, light intensity density at 365 nm of 50 rnW/cm ² ). The PdAu-hydroxyethyl cobalt obtained by the reaction is centrifuged, dried, calcined at 350 ° C for 5 h to obtain a black powder and ground into a fine powder, which is extruded in a mold under a pressure of 40 kN, and is crushed and sieved to obtain a pellet. Catalyst particles having a diameter of 60 to 80 mesh. The catalytic reaction conditions are: the temperature of the catalytic reaction is 200~450'C, the pressure is normal pressure; the total flow rate of the reaction is 50 mL/min, wherein the flow rates of the three gases are CH ₄ :0 ₂ :N ₂ =1 : 10:89; The space velocity is 30000 mL/(g-h), and the reaction results are shown in Table 1. Example 8

This embodiment provides a method for preparing 3% PdAu(3:1)Co ₃ 0, nanosheet, comprising the steps of: weighing 7.5 mmol of cobalt acetate tetrahydrate (Co(CH ₃ COO) ₂ '43⁄40) and 1.5

?? (1\^=48000) dissolved in 7511]1 ethylene glycol, stirred and dissolved, transferred to high pressure reactor, heated at 180 ° C for 24 h, cooled to room temperature, centrifuged with deionized water, washed, after Vacuum drying at 60 'C for 12 h gave hydroxyethyl cobalt nanosheets. The hydroxyethyl cobalt nanosheet was dispersed in water to obtain a dispersion of hydroxyethyl cobalt (78 mM, 30 mL), and '5 mL of a mixed aqueous solution of 32 g of Pd (N0 ₃ ) and 0.0022 g of AuCl _{3 was added} , followed by an aqueous solution. The dispersion was placed in a xenon lamp (6A, light intensity density at 365 nm of 50 mW/cm ² ) and irradiated at room temperature for 15 min. The PdAu-hydroxyethyl cobalt obtained by the reaction was centrifuged, dried, and calcined at 400 ° C. h obtained a clean color powder and ground into a fine powder, extruded in a mold under a pressure of 40 kN, and crushed and sieved to obtain catalyst particles having a particle diameter of 60 to 80. The catalytic reaction conditions are: the temperature of the catalytic reaction is 200. ~450'C, the pressure is normal pressure; the total flow rate of the reaction is 50mLAnin, wherein the flow rate of these three gases is C3⁄4:0 ₂ :N _r l :10:89; the space velocity is 30000 m!J(g' h) The reaction results are shown in Table 1. Example 9

This embodiment provides a method for preparing 3% PdAu(l:10)'-Co ₃ (3⁄4 nanosheet), comprising the steps of: weighing 7.5 mmol Cobalt acetate tetrahydrate (Co(CH ₃ COO) ₂ '4H ₂ 0) and 1.5 mmol PVP (Mw=48000) are dissolved in 75 mL of diethylene glycol, stirred and dissolved, and transferred to a high pressure reactor at 1 SO ' C ^ F hydrothermal 12 h, cooled to room temperature, centrifuged with deionized water, washed, vacuum dried at 60 ° C for 12 h, to obtain light ethyl cobalt nanosheets _d disperse hydroxyethyl cobalt nanosheets in water A dispersion of hydroxyethyl cobalt (78 mM, 30 mL) was obtained, and 5 mL of a mixed aqueous solution of 0.0008 g of Pd(0 ₃ ) and 0,0040 g of AuCl _{3 was added to the} aqueous solution, and then the dispersion was placed in a xenon lamp (6A, 365 nm). The intensity of the light is 50 mW/cm ² ) and the room temperature is irradiated for 15 min. The PdAu-hydroxyethyl cobalt obtained by the reaction was centrifuged, dried, calcined at 350 ° C for 3 h to obtain a black powder and ground into a fine powder, which was extruded in a mold under a pressure of 40 k, and was crushed and sieved. Catalyst particles having a particle size of 60 to 80 mesh. The catalytic reaction conditions are: the temperature of the catalytic reaction is 200~450 'C, the pressure is normal pressure; the total flow rate of the reaction is 50 mL/min, wherein the flow rates of the three gases are CH _4: 0 ₂ : N ₂ =1: 10:89; the space velocity is 30000 mL/(g-h), and the reaction results are shown in Table 1. Example 10

This embodiment provides a method for preparing a 3% Pd-NiO nanosheet, which comprises the steps of: weighing 0.75 mmol of nickel acetate tetrahydrate (Ni (CH ₃ COO) ₂ -4H ₂ 0) and 1.5 mmol of PVP (Mw=24000) Dissolved in 75 mL of ethylene glycol, stirred and dissolved, transferred to an autoclave, heated to water for 12 h at 180 Torr, cooled to room temperature, centrifuged with deionized water, washed, and dried under vacuum at 60 Torr for 12 h. , obtaining nickel hydroxide nanosheets. The nickel hydroxide nanosheet was dispersed in water to obtain a nickel hydroxide dispersion (82 mM, 30 mL), and 5 mL of a 17.4 mg Pd(N0 ₃ ) ₂ solution was added, and then the dispersion was placed in a xenon lamp (6A, 365). The light intensity at nm was 50 mW/cm ² ) and the room temperature was irradiated for 15 min. The Pd-tL nickel oxide obtained by the reaction was centrifuged, dried and calcined at 400 °C for 1 h to obtain 3% Pd-NiO nanosheets. The morphology is shown in Fig. 6a to Fig. 6b, and the XRD pattern is shown in Fig. 7. The fine powder is extruded in a mold under a pressure of 40 kN, and crushed and sieved to obtain catalyst particles having a particle diameter of 60 to 80 mesh. The catalytic reaction conditions are: the temperature of the catalytic reaction is 200~450 'C, the pressure is normal pressure; the total flow rate of the reaction is SO mUmin, wherein the flow rates of the three gases are CH _4: 0 _2: N ₂ =1 : 10 :89; The space velocity is 30000 mL/(g-h), and the reaction results are shown in Table 1 and Figure 8. Example 11

This embodiment provides a method for preparing a 3% Au-NiO nanosheet, comprising the steps of: weighing 2.5 mmol of nickel acetate tetrahydrate (Ni (CH ₃ COO) ₂ -4H ₂ 0) and 2 mmol of PVP (Mw=24000) Dissolved in 75 mL of ethylene glycol, stirred and dissolved, transferred to a high pressure reaction kettle, heated to water at 170 Torr for 24 h, cooled to room temperature, centrifuged with deionized water, washed, and dried under vacuum at 60 Torr for 12 h. , obtaining nickel hydroxide nanosheets. The 3⁄4 nickel oxide nanosheet was dispersed in water to obtain a nickel hydroxide dispersion (82 mM, 30 mL), and force B was added to 5 mL of a 8.7 mg AuCl ₃ solution, after which the dispersion was placed in a xenon lamp. (10A, 365 run light intensity density of 96 mW / cm ² ), room temperature exposure for 15min. Reaction of nickel hydroxide Au- centrifuged, dried at 350 'C calcined 5 h to give the 3% Au- NiO nano-sheet, which was finely pulverized ^ ^1, in the extrusion die at a pressure of 40 kN After molding, the catalyst particles having a particle diameter of 60 to 80 are obtained by crushing and sieving. The catalytic reaction conditions are: the temperature of the catalytic reaction is 200~450, the pressure is normal pressure; the total flow rate of the reaction is 50 mL/min, wherein the flow rate of the gas is C3⁄4:O ₂ :N ₂ =l:10:89; The rate is 10000 mL/(g'h), and the reaction results are shown in Table 1. Example 12

This embodiment provides a method for preparing a 3% PdAu (1:1)-NiO nanosheet, comprising the steps of: weighing 10 mmol of nickel acetate tetrahydrate (Ni (CH ₃ COO) ₂ '4H ₂ 0) and 2 mmol PVP (Mw=24000) was dissolved in 75 mL of diethylene glycol, stirred and dissolved, transferred to a high pressure reactor, and heated at 180 ° C for 48 h, cooled to room temperature, centrifuged with deionized water, and washed. Vacuum drying at 60 'C for 12 h gave nickel hydroxide nanosheets. The nickel hydroxide nanosheet was dispersed in water to obtain a nickel hydroxide dispersion (82 mM, 30 mL), and 5 mL of 8.7 mg Pd(0 ₃ ) ₂ and 4.4 mg AuClj solution was added, and then the dispersion was placed in a xenon lamp. (10A, 365 nra at a light intensity of 96 mW/cm ² ), and irradiated at room temperature for 15 min. The PdAu-nickel hydroxide obtained by the reaction was separated by centrifugation, calcined at 300 ° C for 5 h to obtain 3% PdAu-NiO nanosheets, which were ground into fine powder and extruded in a mold under a pressure of 40 kN. After crushing and sieving, catalyst particles having a particle diameter of 60 to 80 mesh are obtained. The catalytic reaction conditions are: the temperature of the catalytic reaction is 200~450 'C, the pressure is normal pressure; the total flow rate of the reaction is 50 mL/min, wherein the flow ratio of the three gases is C:0 ₂ :N ₂ =1:10 :89; The space velocity is 20000 mL/(g'h), and the reaction results are shown in Table 1. Example 13

This embodiment provides a method for preparing a 3% PdAu (10:1)-NiO nanosheet, comprising the steps of: weighing 10 mmol of nickel acetate tetrahydrate (Ni (CH ₃ COO) ₂ H ₂ 0) and 4 mnlol PVP ( Mw=24000) dissolved in 75 mL of ethylene glycol, stirred and dissolved, transferred to an autoclave, heated at 180 °C for 12 h, cooled to room temperature, centrifuged with deionized water, washed, and then washed at 60 Ό. The vacuum was dried for 12 h to obtain nickel hydroxide nanosheets. The nickel hydroxide nanosheet was dispersed in water to obtain a nickel hydroxide dispersion (82 mM, 30 mL), and 5 mL of 15.9 mg Pd(N0 ₃ )^il 0.8 mg AuCl ₃ solution was added, and then the dispersion was placed. The flow lamp (15A, light intensity at 365 nm was 150 mW/cm ² ) was irradiated for 15 min at room temperature. The PdAu-nickel hydroxide obtained by the reaction was centrifuged, dried, and calcined at 400 ° C for 3 h to obtain 3% PdAu-NiO nanosheets, which were ground into fine powder and extruded in a mold under a pressure of 40 kN. After crushing and sieving, catalyst particles having a particle diameter of 60 to 80 tl are obtained. The catalytic reaction conditions are: the temperature of the catalytic reaction is 200~450 'C, the pressure is normal pressure; the total flow rate of the reaction is 50mL Anin, wherein the flow ratio of the three gases is C:O ₂ :N ₂ =l:10:89; The airspeed is 20000 m!J(g' h), anti The results should be shown in Table 1. Example 14

This embodiment provides a method for preparing a 3% Pd-NiCo ₂ 0 „nano' sheet, 'including the steps: weigh 0.75 mmol of nickel acetate tetrahydrate (Ni (CH ₃ COO) ₂ '43⁄40), 1.5 mmol of tetrahydrate acetic acid Cobalt (Co (CH ₃ COO) ₂ -4H ₂ 0) and 1.5 mmol PVP (Mw = 24000) were dissolved in 75 mL of ethylene glycol, stirred and dissolved, and transferred to a pressure reactor, where water was heated at 80 ° C. 12 h, cooled to room temperature, centrifuged with deionized water, washed, and dried under vacuum at 60 Torr for 12 h to obtain cobalt nickel precursor nanosheets. Disperse cobalt nickel precursor nanosheets in water to obtain cobalt nickel precursors. Disperse system (40 mM, 30 mL), add 5 mL of 27.4 mg Pd(N0 ₃ ) ₂ solution, then place the dispersion in a xenon lamp (6 A, 650 nm light intensity density 50 mW/cm ² ) After irradiation for 15 minutes at room temperature, the reaction was centrifuged, dried, and calcined at 400 ° C for 3 h to obtain 3% Pd-NiCo ₂ 0, nanosheets, which were ground into fine powder and extruded in a mold under a pressure of 40 kN. After crushing and sieving, catalyst particles having a particle size of 60 to 80 are obtained. The catalytic reaction conditions are: the temperature of the catalytic reaction is 200 to 450 V, and the pressure is atmospheric pressure. The total flow rate of the reaction was 50 mL / min, with a flow rate ratio of these two gases _{_{C¾: 0 2: N 2 =}} 1: 10: 89: a space velocity of 30000 mL / (g- h), the reaction results shown in Table 1. Example 15

This embodiment provides a method for preparing an SC/c Au-NiCoz^ nanosheet, comprising the steps of: weighing 1.0 mmol of nickel acetate tetrahydrate (Ni (CH ₃ COO) ₂ '4H ₂ 0), 2.0 mmol of cobalt acetate tetrahydrate (Co (CH ₃ COO) ₂ -4H ₂ 0) and 2 mmol PVP (Mw=24000) were dissolved in 75 mL of ethylene glycol, stirred and dissolved, transferred to an autoclave, and heated at 190 °C for 24 h. After cooling to room temperature, centrifugation with deionized water, washing, and vacuum drying at 60 ° C for 12 h, a cobalt nickel precursor nanosheet was obtained. Disperse the cobalt nickel precursor nanosheet in water to obtain a dispersion of cobalt nickel precursor (40 mM, 30 mL), add 5 mL of 13.7 mg AuCl ₃ solution, and then place the dispersion in a xenon lamp (6A, 365 nm). The light intensity was 50 mW/cm ² ) and the room temperature was irradiated for 15 min. The Au-cobalt-nickel precursor obtained by the reaction was centrifuged, dried, and calcined at 450 Torr for 1 hour to obtain 3% Au-NiCo ₂ 0 ₄ nanosheet, which was ground into a fine powder and extruded in a mold at a pressure of 40 kN. After molding, the catalyst particles having a particle diameter of 60 to 80 are obtained by crushing and sieving. The catalytic reaction conditions are as follows: the temperature of the catalytic reaction is 200 to 450. C, the pressure is normal pressure; the total flow rate of the reaction is 50 mL/min, wherein the flow rates of the three gases are C3⁄4:0 ₂ :N ₂ =1 :10:89; the space velocity is 10000 mL/(g' h) The reaction results are shown in Table 1. Example 16

This embodiment provides a method for preparing a Sn/o PdAuU J t MQ^C^ nanosheet, comprising the steps of: weighing 2.0 mmol Nickel acetate tetrahydrate (Ni(CH ₃ COO) ₂ 43⁄40>, 6.0 mmol of cobalt acetate tetrahydrate (Co (CH ₃ COO) ₂ '4 0 ) and 2 mmol PVP (Mw=24000) dissolved in 75 mL of ethylene glycol After stirring and dissolving, transfer to a high pressure reaction kettle, heat it at 170 Torr for 24 h, cool to room temperature, centrifuge with deionized water, wash, and dry at 60 ° C for 12 h to obtain cobalt nickel precursor nanosheets. Disperse the nickel precursor precursor nanosheet in water to a dispersion of cobalt nickel precursor (40 m, 30 mL), add 5 mL of a mixed solution of 2.5 mg Pd(N0 ₃ ) ₂ and 12.5 mg AuCl ₃ , then The dispersion was placed in a xenon lamp (6A, light intensity at 365 nm, 50 mW/cm ² ), and exposed to room temperature for 15 min. The PdAu-cobalt nickel precursor obtained by the reaction was centrifuged, dried, and calcined at 350 Torr for 3 h. 3% PdAu-NiCo ₂ 0 ₄ nanosheets, which were ground into a fine powder 'extruded in a mold under a pressure of 40 kN, and crushed and sieved to obtain catalyst particles having a particle size of 60 to 80. The catalytic reaction conditions were : The temperature of the catalytic reaction is 200~450 V, and the pressure is normal pressure; the total flow rate of the reaction is 50 mL/min, among which these three gases Flow rate ratio of _{_{CH4: O 2: N 2 =}} l: 0:89]; a space velocity of 10000 mL / (g'h), results of the reaction are shown in Table 1. Embodiment Π

The present embodiment provides a method for preparing a S PdAuUf NiCc^Oo nanosheet, comprising the steps of: weighing 1.0 mmol of nickel acetate tetrahydrate (Ni(CH ₃ COO) ₂ '4H ₂ 0), 2.0 mmol of cobalt acetate tetrahydrate ( Co (CH ₃ COO) ₂ '4H ₂ 0) and 5 mmol PVP (Mw=10000) were dissolved in 75 mL of Ethylene, stirred and dissolved, transferred to a high pressure reactor, and heated at 180 ° C for 12 h, cooled to After centrifugation at room temperature, it was centrifuged in deionized water, and dried under vacuum at 60 Torr for 12 h to obtain a cobalt nickel precursor nanosheet. The cobalt nickel precursor nanosheet was dispersed in water to obtain a dispersion of cobalt nickel precursor (40 mM, 30 mL), and 5 mL of a mixed solution of 24.9 mg Pd(N0 ₃ ) ₂ and 1.3 mg AuCl _{3 was added} , and then the dispersion was dispersed. The system was placed in a xenon lamp (6A, light intensity density at 50 mW/cm ² at 365 nm) and irradiated at room temperature for 15 min. The PdAu-cobalt-nickel precursor obtained by the reaction was centrifuged, dried, and calcined at 400 Torr for 3 hours to obtain 3% PdAu-NiCo ₂ 0 ₄ nanosheet, which was ground into a fine powder and extruded in a mold under a pressure of 40 kN. After crushing and sieving, catalyst particles having a particle diameter of 60 to 80 mesh are obtained. The catalytic reaction conditions are: the temperature of the catalytic reaction is 200~450 C, the pressure is normal pressure; the total flow velocity of the reverse is 50 niL/min, and the flow rate ratio of the three gases is CH ₄ :0 ₂ :N ₂ =1: 10:89; the open space is 30,000 mL/(g-h), and the reaction results are shown in Table 1 „Example 18

The present embodiment provides a 10% PdAu (l: l) NiCo 2 04 nanosheet production method, comprising the steps of: Weigh 2.0 mmol of nickel acetate tetrahydrate _{_{(Ni (CH 3 COO) 2}} '4 0), 6.0 mmol four Cobalt acetate (Co (CH ₃ COO) ₂ -4 0> and 1 mmol PVP (Mw = 48000) were dissolved in 75 mL of ethylene glycol, stirred and dissolved, transferred to a high pressure reactor, and heated to a lower temperature for 24 h, cooled to After centrifugation at room temperature, washing with deionized water, vacuum drying at 60 Torr for 12 h to obtain cobalt nickel precursor nanosheets. Cobalt nickel precursor nanosheets were dispersed in water to obtain a dispersion of cobalt nickel precursor (40 mM, 30 mL), Add 5 mL of 46.6 mg Pd(N0 ₃ )^B 23.4 mg AuCl ₃ mixed solution, then place the dispersion in a xenon lamp (6A, 650 nm light intensity density 50 mW/cm ² ), and irradiate for 15 min at room temperature. . The PdAu-cobalt nickel precursor obtained by the reaction was centrifuged, dried, and calcined at 400 ° C for 1 h to obtain 10% PdAu-NiCo ₂ 0 ₄ nanosheet, which was ground into a fine powder under a pressure of 40 kN. The mold is extruded, and after crushing and sieving, catalyst particles having a particle diameter of 60 to 80 are obtained. The catalytic reaction conditions are: the temperature of the catalytic reaction is 200~450 °C, the pressure is normal pressure; the total flow rate of the reaction is 50 mL/min, wherein the flow rates of the three gases are CH ₄ :O ₂ :N ₂ =l : The airspeed of 10:89 _f is 60000 mU(g'h), and the reaction results are shown in Table 1.

Table 1 Catalysts of Examples 1 to 18 catalyze the combustion reaction of formazan

The invention adopts the hydrothermal synthesis method and the light irradiation method to prepare a metal oxide supported noble metal catalyst, and the preparation method is simple and easy to operate, and the prepared catalyst has uniform morphology and good stability, and can be applied to the catalytic combustion reaction of formazan to make CH. ₄ When the reaction temperature is below 400 'C, the conversion rate of formazan can be as high as 100%, and it has good low temperature oxidation activity of methylate. At the same time, the metal oxide supported noble metal catalyst has the advantages of good stability, long life, good water resistance, and the like. 310~50 (continuous operation for more than 100 hours under TC has no obvious deactivation phenomenon, and has good industrial application prospects.

Therefore, the present invention effectively overcomes various shortcomings in the prior art and has high industrial utilization value.

The above-described embodiments are merely illustrative of the principles of the invention and its advantages, and are not intended to limit the invention. Modifications or variations of the above-described embodiments may be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, various modifications and changes made by those skilled in the art without departing from the spirit and scope of the invention are intended to be covered by the appended claims.

Claims

Claims - a metal oxide supported noble metal catalyst characterized by comprising a F component: a noble metal, an oxide of a noble metal and a metal oxide, the precious metal catalyst supported by the metal oxide, a noble metal S ratio of the total mass of the right foot · ¾ ¹ mass of metal and metal oxide is 100, and the metal oxide supported noble metal catalyst is a two-dimensional structure. The metal oxide-supported noble metal catalyst according to claim 1, wherein the metal oxide-supported noble metal catalyst is a nanosheet, and a ratio of a maximum diameter to a thickness of the nanosheet is not less than 10. The metal oxide-supported noble gold catalyst according to claim 1, wherein the metal oxide is selected from one or a combination of two of Co and Ni. The metal oxide-supported noble gold rot catalyst according to claim 2, wherein when the metal of the gold sulphate is a combination of Co and Ni, the ratio of Ni to Co is 1:2. The metal oxide-supported noble ruthenium catalyst according to claim 1, wherein the noble metal is selected from one or a combination of two of Pb and Au. The catalyst for the gold-stirred oxide loading according to claim 4, wherein when the noble metal element is a combination of Pd and Au, the mass ratio of Pel to Au is h 10-10, 1. - A method for preparing a metal oxide supported noble metal catalyst according to any one of claims 1 to 6, characterized in that:

In the diol system, the metal salt is co-dissolved with the alkaline surfactant, and the two-dimensional metal precursor is obtained by hydrothermal, centrifugal separation and drying;

The two-dimensional metal precursor is dispersed in a solution, and the permeated metal salt solution is added according to the composition ratio of the catalyst, and the metal oxide-supported noble metal catalyst is obtained by light, centrifugal washing, drying and calcination. The method for preparing a metal vapor-supported noble metal catalyst according to claim 7. It is characterized in that: Γ, comprising the following steps:

Step 1>, dispersing the metal salt and the alkaline surface active agent in the diol, and separating the two-dimensional metal precursor by hydrothermal, centrifugal separation and drying; Step 2), dispersing the two-dimensional metal precursor in a solution, adding a precious metal salt solution according to a composition ratio of the catalyst, and illuminating the noble metal on the two-dimensional metal precursor by using a xenon lamp;

Step 3), the dispersion solution obtained in the step 2) is subjected to centrifugal separation, drying and calcination to obtain a metal oxide-supported noble metal catalyst. The method for preparing a metal oxide supported metal catalyst according to claim 7 or 8, wherein the ratio of the metal salt, the alkaline surfactant and the glycol is 0.5-10 mmol: 0.5~ 5 mmol: 75 mL. The method for preparing a metal oxide supported noble metal catalyst according to claim 7 or 8, wherein the glycol is used as a solvent and a chelating agent in the reaction, and one of ethylene glycol and diethylene glycol is selected. The invention relates to a method for preparing a metal oxide supported noble metal catalyst according to claim 7 or 8, wherein the alkaline surfactant is selected from polyvinylpyrrolidone of different molecular weight, The molecular weight includes one or a combination of two or more of 10000 g/moK 24000 g/moK and 48000 g/mol. The method for preparing a metal oxide supported noble metal catalyst according to claim 7 or 8, wherein the hydrothermal reaction temperature of the two-dimensional metal precursor is 170 to 200 ° C, and the water heat of the two-dimensional metal precursor The reaction time was 12^48 h. The method for preparing a metal oxide supported noble metal catalyst according to claim 7 or 8, wherein the metal salt has a concentration of 0.004 to 0.009 mol/L, and the metal according to claim 7 or A method for preparing an oxide-supported noble metal catalyst, characterized in that the noble metal salt comprises one or a combination of a palladium salt and a gold salt. The metal oxide supported noble metal catalyst according to claim 7 or 8. The preparation method is characterized in that the noble gold salt is selected from one or a combination of palladium nitrate and gold chloride. Preparation of the metal oxide supported noble metal catalyst according to claim 7 or The method is characterized in that the corresponding power density of the light at a wavelength of 365 nm is 0 to 150 mW/cm ² . The method for preparing a metal oxide supported noble metal catalyst according to claim 7 or 8, characterized in that roasting The temperature is 300~450Ό, and the baking time is 1~5 hours. Use of a metal oxide supported noble metal catalyst according to any one of claims 1 to 6 for use in a catalytic combustion reaction of methane. The use of the metal oxide supported noble metal catalyst according to claim 18, wherein the methane catalytic combustion reaction conditions are: a reaction temperature of 200 to 450X:, a reaction pressure of normal pressure; and a total flow rate of the reaction is 50~ 100 mL/min, the reaction gases include CH ₄ , 0 ₂ and 1 ^ ₂ , the flow ratio of C , 0 ₂ and N ₂ is 1:5~15:84~94, and the space velocity is 10000~120000 mL/(g - h), the number of catalysts is 60-80 mesh. The use of a metal oxide negative-cut noble metal catalyst according to claim 19, wherein the formazan is completely converted at a reaction temperature of 300 to 400 ° C