Preparation method and application of palladium-platinum diatomic VOC oxidation catalyst

Abstract

The present invention relates to a preparation method and application of a palladium-platinum diatomic VOC oxidation catalyst, and the preparation method comprises the steps of: preparing a palladium compound and a platinum compound into a palladium-platinum mixture precursor solution; mixing a protective agent and a reducing agent evenly and heating to 180-250°C to obtain a mixed solution; slowly adding the palladium-platinum mixture precursor solution to the mixed solution for reaction, and obtaining a catalyst after the reaction is completed. The present invention adopts a slow synthesis method of thermally reducing a palladium-platinum precursor with a reducing agent, and obtains a palladium-platinum diatomic site catalyst with two metal atoms uniformly dispersed at the level of nanometer size effect. The catalyst prepared by the present invention has a high oxidation reaction activity of VOC, even surpassing the current best pure Pt catalyst.

Description

Technical Field

[0001] The invention relates to the technical field of thermal catalysis, and in particular to a preparation method and application of a palladium-platinum diatomic VOC oxidation catalyst. Background Art

[0002] Volatile organic compounds (VOCs) are one of the main components of air pollutants. Most of them have a special unpleasant odor and are toxic, irritating, teratogenic and carcinogenic. In addition, VOCs are also important precursors to secondary pollutants such as fine particles and ozone, which in turn cause atmospheric environmental problems such as haze and photochemical smog.

[0003] VOC emissions pose serious threats to the natural environment and human health. Currently, catalytic oxidation is considered the most promising technology for VOC control, and the development of efficient VOC oxidation catalysts is the core of this technology.

[0004] Palladium (Pd) and platinum (Pt) are widely used due to their advantages such as high VOC oxidation activity, good selectivity and low conversion temperature. Among them, Pt has higher heat resistance and hydrothermal resistance than Pd. Compared with Pt, Pd can provide higher activity for the catalytic oxidation of various VOCs.

[0005] With increasingly stringent environmental regulations, in order to better eliminate VOCs, it is necessary to further improve the activity of VOC treatment catalysts. Summary of the invention

[0006] Based on this, it is necessary to provide a preparation method and application of a palladium-platinum diatomic VOC oxidation catalyst.

[0007] To achieve the above object, the present invention provides a technical solution:

[0008] A method for preparing a palladium-platinum diatomic VOC oxidation catalyst comprises the following steps:

[0009] preparing a palladium-platinum mixture precursor solution by using a palladium compound and a platinum compound;

[0010] The protective agent and the reducing agent are mixed evenly and heated to 180-250°C to obtain a mixed solution;

[0011] The palladium-platinum mixture precursor solution is added to the mixed solution for reaction, and the catalyst is obtained after the reaction is completed.

[0012] Preferably, the specific steps of preparing a palladium compound and a platinum compound into a palladium-platinum mixture precursor solution include:

[0013] The palladium compound and the platinum compound are dissolved in a solvent and mixed evenly to obtain the palladium-platinum mixture precursor solution.

[0014] Preferably, the molar ratio of the palladium element to the platinum element in the palladium compound and the platinum compound is 0:1 to 1:0.

[0015] Preferably, the volume molar concentration of the palladium-platinum mixture precursor solution is 1 to 500 mol / L.

[0016] Preferably, the volume concentration of the diethylene glycol aqueous solution is 50-100%.

[0017] Preferably, the palladium compound includes at least one of palladium chloride hydrate, palladium chloride, palladium nitrate, ammonium chloropalladate, dinitrosodiammine palladium, potassium hexachloropalladate, potassium tetrachloropalladate, sodium hexachloropalladate, sodium tetrachloropalladate, palladium acetylacetonate and palladium acetate.

[0018] Preferably, the platinum compound includes at least one of potassium chloroplatinate, chloroplatinic acid hydrate, platinum tetrachloride, sodium chloroplatinite, sodium hexachloroplatinate, tetrachloroplatinum, tetraammineplatinate, cisplatin, ammonium chloroplatinate, potassium chloroplatinite, tetraammineplatinum nitrate, potassium tetranitroplatinate (II), potassium trichloroammineplatinate (II) and tetraammineplatinum chloride hydrate.

[0019] The protective agent includes at least one of poly N-vinyl-2-pyrrolidone, polyethylene glycol, polyvinyl alcohol, polyvinyl ether, poly (meth) acrylic acid, poly (meth) acrylic acid salt, sodium alginate and cellulose derivatives.

[0020] Preferably, the reducing agent includes at least one of diethylene glycol, methanol, ethanol, n-propanol, isopropanol, n-butanol, pentanol, hexanol, ethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, butylene glycol, dibutylene glycol, tributylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, butylene glycol monomethyl ether, butylene glycol monoethyl ether, glycerol, diglycerol, polyglycerol, trimethylolpropane, pentaerythritol and oleylamine.

[0021] Preferably, in parts by weight, the raw materials for preparing the catalyst include:

[0022] 1 part of palladium compound and platinum compound;

[0023] 0.1 to 20 parts of protective agent; and

[0024] 10 to 1000 parts of reducing agent.

[0025] The present invention also provides use of a catalyst prepared by the method for preparing the catalyst described in any one of the above in VOC oxidation.

[0026] Beneficial effects of the present invention:

[0027] Palladium and platinum are immiscible metals at the bulk scale. The present invention adopts a slow synthesis method of thermally reducing a palladium-platinum precursor with a reducing agent, and obtains a palladium-platinum diatomic site catalyst with two metal atoms uniformly dispersed at the atomic level through the nano-size effect. The diatomic site catalyst (DASC) is composed of dimetallic atoms uniformly distributed at the atomic level, and can achieve continuous regulation of the electronic state and surface state of the catalyst by changing the ratio of elements in the DASC, so that the reactant molecules reach the optimal adsorption state, thereby greatly improving the activity. The catalyst prepared by the present invention has high VOC oxidation reaction activity. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is the XRPD spectrum of catalyst 1;

[0029] Figure 2 is the XRPD spectrum of catalyst 2;

[0030] Figure 3 is the XRPD spectrum of catalyst 3;

[0031] Figure 4 is the XRPD spectrum of catalyst 4;

[0032] Figure 5 is the XRPD spectrum of catalyst 5;

[0033] Figure 6 It is a comparison diagram of XRPD spectra of catalysts 1-5;

[0034] Figure 7 is the catalytic activity curve of catalyst 1;

[0035] Figure 8 is the catalytic activity curve of catalyst 5;

[0036] Fig. 9 is the catalytic activity curve of catalyst 3;

[0037] Fig.10 is the catalytic activity curve of catalyst 2;

[0038] Fig.11 is the catalytic activity curve of catalyst 4;

[0039] Fig.12 The catalytic activity curves of catalysts 1-5 are summarized;

[0040] Fig.13 Pd x Pt 1-x Pd 3dXPS patterns of catalysts (x = 0, 0.5, 0.7), calibrated to carbon;

[0041] Fig.14 Pdx Pt 1-x Pt4f XPS patterns of catalysts (x = 0.5, 0.7, 1), calibrated with carbon;

[0042] Fig.15 This is the in-situ FTIR spectrum of the Pt catalyst adsorbed to a steady state at 70°C in a C3H6 atmosphere;

[0043] Fig.16 Pd 0.5 Pt 0.5 In situ FTIR spectrum of the diatomic site catalyst adsorbed to a steady state at 70°C in C3H6 atmosphere;

[0044] Fig.17 The diagram is the mechanism of C3H6 oxidation on pure Pt catalyst;

[0045] Fig.18 Pd 0.5 Pt 0.5 Diagram of the C3H6 oxidation mechanism over diatomic site catalysts. DETAILED DESCRIPTION

[0046] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0047] In the examples, the test methods used are conventional methods unless otherwise specified, and the materials, reagents, etc. used are all commercially available unless otherwise specified.

[0048] A method for preparing a platinum-palladium diatomic VOC oxidation catalyst comprises the following steps:

[0049] S100. preparing a palladium compound and a platinum compound into a palladium-platinum mixture precursor solution;

[0050] The specific steps of preparing a palladium-platinum mixture precursor solution from a palladium compound and a platinum compound include:

[0051] The palladium compound and the platinum compound are dissolved in a solvent and mixed evenly to obtain a palladium-platinum mixture precursor solution.

[0052] Specifically, the solvent is also used as a reducing agent, and the solvent includes at least one of diethylene glycol, methanol, ethanol, n-propanol, isopropanol, n-butanol, pentanol, hexanol, ethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, butylene glycol, dibutylene glycol, tributylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, butylene glycol monomethyl ether, butylene glycol monoethyl ether, glycerol, diglycerol, polyglycerol, trimethylolpropane, pentaerythritol and oleylamine.

[0053] In some embodiments, the volume concentration of the solvent is 50-100%.

[0054] S200. The protective agent and the reducing agent are mixed and heated to 180-250°C to obtain a mixed solution;

[0055] S300. Add a palladium-platinum mixture precursor solution to the mixed solution for reaction, and obtain a catalyst after the reaction is completed.

[0056] Specifically, the protective agent is used to prevent the nanoparticles from agglomerating too large.

[0057] Taking triethylene glycol as the reducing agent and potassium tetrachloropalladate and potassium chloroplatinate as the palladium-platinum mixture precursors as an example, the reaction process is as follows:

[0058]

[0059] Specifically, after the reaction is completed, the product is washed with an organic solvent, and the catalyst is obtained after the washing is completed.

[0060] More specifically, the active solvent includes at least one of acetone, methanol, ethanol, isopropanol, petroleum ether, ethyl ether, dichloromethane, n-butanol, glycerol, ethylene glycol, tetrahydrofuran, dimethyl sulfoxide, N,N-dimethylformamide, methyl acetate, ethyl acetate, propyl acetate, pentane, hexane, octane, benzene, toluene, xylene, methyl butyl ketone, methyl isobutyl ketone, cyclohexane, cyclohexanone and toluene-cyclohexanone.

[0061] In some embodiments, the molar ratio of the palladium element to the platinum element in the palladium compound and the platinum compound is 0:1 to 1:0.

[0062] In some embodiments, the molar concentration of the palladium-platinum mixture precursor solution is 1-500 mol / L.

[0063] In some embodiments, the palladium compound includes at least one of palladium chloride hydrate, palladium chloride, palladium nitrate, ammonium chloropalladate, dinitrodiamminepalladium, potassium hexachloropalladate, potassium tetrachloropalladate, sodium hexachloropalladate, sodium tetrachloropalladate, palladium acetylacetonate, and palladium acetate.

[0064] In some embodiments, the platinum compound includes at least one of potassium chloroplatinate, chloroplatinic acid hydrate, platinum tetrachloride, sodium chloroplatinite, sodium hexachloroplatinate, tetrachloroplatinum, tetraammineplatinate, cisplatin, ammonium chloroplatinate, potassium chloroplatinite, tetraammineplatinum nitrate, potassium tetranitroplatinate (II), potassium trichloroammineplatinate (II), and tetraammineplatinum chloride hydrate.

[0065] In some embodiments, the protective agent includes at least one of poly(N-vinyl-2-pyrrolidone), polyethylene glycol, polyvinyl alcohol, polyvinyl ether, poly(meth)acrylic acid, poly(meth)acrylate, sodium alginate, and cellulose derivatives.

[0066] In some embodiments, the reducing agent includes at least one of diethylene glycol, methanol, ethanol, n-propanol, isopropanol, n-butanol, pentanol, hexanol, ethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, butylene glycol, dibutylene glycol, tributylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, butylene glycol monomethyl ether, butylene glycol monoethyl ether, glycerol, diglycerol, polyglycerol, trimethylolpropane, pentaerythritol and oleylamine.

[0067] In some embodiments, the catalyst preparation raw materials include, by weight:

[0068] 1 part of palladium compound and platinum compound;

[0069] 0.1 to 20 parts of protective agent; and

[0070] 10 to 1000 parts of reducing agent.

[0071] The present invention also provides use of a catalyst prepared by the method for preparing the catalyst described in any one of the above in VOC oxidation.

[0072] It is worth noting that the catalysts not specifically mentioned in the above text are all palladium-platinum diatomic VOC oxidation catalysts.

[0073] Example 1

[0074] S100. Dissolve 1.0 mmol (326.4 mg) of potassium tetrachloropalladate and 1.0 mmol (269.6 mg) of potassium chloroplatinate in a mixed solution of 10 ml of water and 30 ml of diethylene glycol to prepare a palladium-platinum mixture precursor solution.

[0075] S200. Mix 440 mg of PVP protective agent and 160 ml of diethylene glycol (178.9 g) evenly and heat to 220° C. to obtain a mixed solution.

[0076] S300. Add the palladium-platinum mixture precursor solution dropwise into the mixed liquid while stirring at a stirring speed of 400 rpm. After stirring for 20 minutes, a black liquid is obtained. The solid is separated by high-speed centrifugation at 9000 rpm, and the by-products are removed by washing with acetone. Catalyst 1 is obtained after drying.

[0077] The Rietveld refinement of the XRPD spectrum of catalyst 1 obtained by X-ray powder diffraction is as follows: Figure 1 .

[0078] Catalyst 1 was loaded onto a γ-alumina carrier powder to prepare a loaded catalyst 1, and was used to test the VOC treatment performance in a complex environment.

[0079] Example 2

[0080] S100. Dissolve 1.4 mmol (427.0 mg) of potassium tetrachloropalladate and 0.6 mmol (208.9 mg) of potassium chloroplatinate in a mixed solution of 10 ml of water and 30 ml of diethylene glycol to prepare a palladium-platinum mixture precursor solution.

[0081] S200. Mix 440 mg of PVP protective agent and 130 ml (145.3 g) of diethylene glycol evenly and heat to 215° C. to obtain a mixed solution.

[0082] S300. Add the palladium-platinum mixture precursor solution dropwise to the mixed liquid while stirring at a stirring speed of 200 rpm. After 20 minutes, a black liquid is obtained. The solid is separated by high-speed centrifugation at 9000 rpm, and the by-products are removed by washing with acetone. Catalyst 2 is obtained after drying.

[0083] The XRPD spectrum of catalyst 2 obtained by X-ray powder diffraction was refined by Rietveld as follows: Figure 4 .

[0084] Catalyst 2 was loaded onto γ-alumina carrier powder to prepare loaded catalyst 4, and was used to test the VOC treatment performance in complex environments.

[0085] Example 3

[0086] S100. Dissolve 0.45 mmol (146.9 mg) of potassium tetrachloropalladate and 0.05 mmol (17.4 mg) of potassium chloroplatinate in a mixed solution of 5 ml of water and 10 ml of diethylene glycol to prepare a palladium-platinum mixture precursor solution.

[0087] S200. Mix 275 mg of PVP protective agent and 80 ml (89.4 g) of diethylene glycol evenly and heat to 240° C. to obtain a mixed solution.

[0088] S300. Add the palladium-platinum mixture precursor solution dropwise to the mixed liquid while stirring at a stirring speed of 400 rpm. After 25 minutes, a black liquid is obtained. The solid is separated by high-speed centrifugation at 9000 rpm, and the by-products are removed by washing with acetone. Catalyst 3 is obtained after drying.

[0089] The XRPD spectrum of catalyst 3 obtained by X-ray powder diffraction was refined by Rietveld as follows: Figure 5 .

[0090] Catalyst 3 was loaded onto γ-alumina carrier powder to prepare loaded catalyst 3, and was used to test the VOC treatment performance in complex environments.

[0091] Example 4

[0092] S100. Dissolve 0.5 mmol (163.2 mg) of potassium tetrachloropalladate in 20 ml of diethylene glycol solution to prepare a palladium compound precursor solution.

[0093] S200. Mix 275 mg of PVP protective agent and 80 ml (89.4 g) of diethylene glycol evenly and heat to 220° C. to obtain a mixed solution.

[0094] S300. Add the palladium compound precursor solution dropwise to the mixed liquid while stirring at a stirring speed of 400 rpm. After 15 minutes, a black liquid is obtained. The solid is separated by high-speed centrifugation at 9000 rpm, and the by-products are removed by washing with acetone. Catalyst 4 is obtained after drying.

[0095] The XRPD spectrum of catalyst 4 obtained by X-ray powder diffraction was refined by Rietveld as follows: Figure 6 , where the black spectral line is the spectral line of sample measurement, the pink spectral line is the calculated spectral line, and the gray spectral line is the error line.

[0096] Catalyst 4 was loaded onto γ-alumina carrier powder to prepare loaded catalyst 6, and was used to test the VOC treatment performance in complex environments.

[0097] Example 5

[0098] S100. Dissolve 0.5 mmol (174.1 mg) of potassium chloroplatinate in 20 ml of diethylene glycol solution to prepare a platinum compound precursor solution.

[0099] S200. Mix 275 mg of PVP protective agent and 80 ml (89.4 g) of diethylene glycol evenly and heat to 220° C. to obtain a mixed solution.

[0100] S300. Add the platinum compound precursor solution dropwise to the mixed liquid while stirring at a stirring speed of 400 rpm. After 16 minutes, a black liquid is obtained. The solid is separated by high-speed centrifugation at 9000 rpm, and the by-products are removed by washing with acetone. After drying, catalyst 5 is obtained.

[0101] The XRPD spectrum of catalyst 5 obtained by X-ray powder diffraction was refined by Rietveld as follows: Figure 7 .

[0102] Catalyst 5 was loaded onto a γ-alumina carrier powder to prepare a loaded catalyst 7, and was used to test the VOC treatment performance in a complex environment.

[0103] VOC treatment performance test in complex environments

[0104] 111 mg of supported catalyst 1, 65 mg of supported catalyst 2, 41 mg of supported catalyst 3, 40 mg of supported catalyst 4, and 83 mg of supported catalyst 5 were placed in a solid bed tubular reactor with quartz wool, and pretreated at 200°C for 1 h under a H2 / N2 atmosphere. After pretreatment, the catalyst was cooled to 40°C and purged with N2 for 5 min. Then, a mixed gas (0.15% NO+0.35% CO+0.033% C3H6+0.25% O2+10% H2O+89.217% N2) in a complex environment was passed through the catalyst bed at a rate of 500 sccm, and the temperature was increased to 600°C at a rate of 10°C / min.

[0105] The C3H6 gas conversion rate at different reaction temperatures under the catalysis of different loaded catalysts was detected by a gas detector.

[0106] Under the catalysis of supported catalysts 1 to 5, the C3H6 conversion rate curves at different temperatures are as follows Figures 7 to 11 As shown. Fig.12 .

[0107] Under the catalysis of supported catalysts 1 to 5, the activation temperature T 50 (The temperature corresponding to 50% conversion rate) is shown in Table 1. The activation temperature T of C3H6 oxidation reaction 50 With Pd x Pt 1-x The corresponding Pd content in the catalyst presents a double volcano shape.

[0108] Table 1 Activation temperature T of C3H6 oxidation reaction 50

[0109] <![CDATA[C3H6 / T 50 ]]> Supported catalyst 1 406℃ Supported Catalyst 2 441℃ Supported Catalyst 3 410℃ Supported Catalyst 4 468℃ Supported Catalyst 5 439℃

[0110] The electron transfer between Pd-Pt diatomic sites was investigated using X-ray photoelectron spectroscopy (XPS). Fig.13 and 14 shown.

[0111] like Fig.13 As shown, in Pd x Pt 1-x As the Pd content decreases, the 3d peak of Pd moves to the high energy side, indicating that x Pt 1-x The number of Pd electrons in the Fig.14 As shown in the figure, with the decrease of Pt content, the 4f peak of Pt moves to the low energy side, indicating that Pd x Pt 1-xThe number of electrons in Pt increases. In summary, electron transfer from Pd to Pt occurs between the Pd-Pt diatomic sites.

[0112] In order to explore Pd 0.5 Pt 0.5 and Pd 0.9 Pt 0.1 The reason why the C3H6 oxidation activity of the diatomic site catalysts (catalysts 1 and 3) is higher than that of pure Pt is measured in a C3H6 atmosphere at 70 °C. x Pt 1-x In-situ FTIR spectra of (x=0, 0.5, 1), Fig.15 This is the in-situ FTIR spectrum of the Pt catalyst adsorbed to a steady state at 70°C in a C3H6 atmosphere. Fig.15 ), at 3100cm -1 、3000cm -1 and 2958cm -1 The C3H6 peak was observed at 1700, 1500, 1240 and 1080 cm -1 The peaks at 1541, 1450 and 1400 cm -1 The peak at 3900 cm -1 To 3600cm -1 Hydroxyl species -OH were observed at , indicating that H2O was produced during the FTIR test, and similar results were observed for pure Pd. These results indicate that C3H6 oxidative cleavage occurred on the pure Pt and Pd samples.

[0113] For Pd 0.5 Pt 0.5 Diatomic site catalysts ( Fig.16 ), at 1666cm -1 and 894cm -1 The peak of Al-CO3 was observed at 1520 cm -1 The peak of Pd-CH3COO was observed at 1860 cm -1 The peak at 2618 cm-1 is believed to be a bridge adsorption species PtPd-CO or a triple adsorption species Pt2Pd-CO, which proves the existence of diatomic sites in the catalyst. -1 and 1022cm -1 The peaks can be attributed to (PdPt)-CH2 and (PdPt)-CHCH3, respectively, indicating that direct dissociation of C3H6 occurs at the Pd-Pt diatomic site. 0.9 Pt 0.1 The phenomenon of diatomic site catalysts is similar, except that 0.5Pt 0.5 Compared with Pd, Pt has fewer Pd-Pt diatomic sites, so it takes longer to reach the steady state, and its C3H6 oxidation activity is slightly lower than that of Pd 0.9 Pt 0.1 .

[0114] The above in situ infrared spectra show that compared with pure Pt and Pd, Pd 0.5 Pt 0.5 and Pd 0.9 Pt 0.1 The intensity of adsorbed species on the diatomic site catalyst is significantly higher, indicating stronger adsorption on the Pd-Pt diatomic site. 0.5 Pt 0.5 and Pd 0.9 Pt 0.1 Adsorbed CH2, CHCH3 and CO species intermediates can be observed on the diatomic site catalysts, indicating that the C3H6 oxidation mechanism of the diatomic site catalysts is different from that of pure Pt and Pd catalysts.

[0115] Fig.17 The C3H6 oxidation mechanism diagram on pure Pt catalyst. Fig.18 Pd 0.5 Pt 0.5 Diagram of the C3H6 oxidation mechanism over diatomic site catalysts.

[0116] like Fig.17 As shown in Figure 2, in pure Pt catalyst, C3H6 can be adsorbed on Pt sites and cracked with the assistance of O atoms in Al2O3 to form Pt-HCHO and Pt-CH3COO species, which are finally converted into CO2. A similar phenomenon occurs for pure Pd catalyst, where C3H6 can be adsorbed on Pd sites and cracked with the assistance of O atoms in Al2O3 to form Pd-HCHO and Pd-CH3COO species, which are finally converted into CO2.

[0117] like Fig.18 As shown, in Pd 0.5 Pt 0.5 In the catalyst, C3H6 directly dissociates at the Pd-Pt diatomic site to form (PdPt)-CH2 and (PdPt)-CHCH3. During the dissociation of C3H6, the π orbital electrons of the C=C double bond are transferred to the dz 2 The orbital undergoes σ feedback, and at the same time, the d yzThe orbital electrons react to the π antibonding orbital of the C=C double bond to generate π negative feedback. Both actions weaken the C=C bond and promote the dissociation of C3H6. With the participation of adsorbed O species, (PdPt)-CH2 may be oxidized to (PdPt)-CO, and finally produce CO2. At the same time, (PdPt)-CHCH3 will be oxidized to Pd-CH3COO intermediate, and then oxidized to CO2. Pd 0.9 Pt 0.1 A similar mechanism exists for catalysts, but the process is slower.

[0118] Therefore, from the above analysis, it can be seen that compared with pure Pt and pure Pd catalysts, Pd 0.5 Pt 0.5 and Pd 0.9 Pt 0.1 The catalyst adsorbed species with higher intensity and C3H6 dissociation was faster, which significantly enhanced the C3H6 oxidation activity.

[0119] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A method for preparing a platinum-palladium diatomic VOC oxidation catalyst, wherein the VOC contains C3H6, characterized in that: Includes steps: The palladium compound and the platinum compound are dissolved in a solvent and mixed evenly to obtain a palladium-platinum mixture precursor solution; The protective agent and the reducing agent are mixed evenly and heated to 180-250°C to obtain a mixed solution; Adding the palladium-platinum mixture precursor solution to the mixed solution for reaction, the reaction time is 15 to 25 minutes, and the catalyst is obtained after the reaction is completed; The solvent is also used as a reducing agent, and the solvent includes at least one of diethylene glycol, methanol, ethanol, n-propanol, isopropanol, n-butanol, pentanol, hexanol, ethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, butylene glycol, dibutylene glycol, tributylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, butylene glycol monomethyl ether, butylene glycol monoethyl ether, glycerol, diglycerol, polyglycerol, trimethylolpropane, pentaerythritol and oleylamine; The raw materials for preparing the catalyst include: 1 part of palladium compound and platinum compound; 0.1~20 parts of protective agent; and Reducing agent 10~1000 parts.

2. The method for preparing a catalyst according to claim 1, characterized in that: The molar ratio of the palladium element to the platinum element in the palladium compound and the platinum compound is 0:1 to 1:

0.

3. The method for preparing the catalyst according to claim 1, characterized in that: The volume molar concentration of the palladium-platinum mixture precursor solution is 1-500 mol / L.

4. The method for preparing the catalyst according to claim 1, characterized in that: The palladium compound includes at least one of palladium chloride hydrate, palladium chloride, palladium nitrate, ammonium chloropalladate, dinitrosodiammine palladium, potassium hexachloropalladate, potassium tetrachloropalladate, sodium hexachloropalladate, sodium tetrachloropalladate, palladium acetylacetonate and palladium acetate.

5. The method for preparing the catalyst according to claim 1, characterized in that: The platinum compound includes at least one of potassium chloroplatinate, chloroplatinic acid hydrate, platinum tetrachloride, sodium chloroplatinite, sodium hexachloroplatinate, tetrachloroplatinum, tetraammineplatinate, cisplatin, ammonium chloroplatinate, potassium chloroplatinite, tetraammineplatinum nitrate, potassium tetranitroplatinate (II), potassium trichloroammineplatinate (II) and tetraammineplatinum chloride hydrate.

6. The method for preparing a catalyst according to claim 1, characterized in that: The protective agent includes at least one of poly N-vinyl-2-pyrrolidone, polyethylene glycol, polyvinyl alcohol, polyvinyl ether, poly (meth) acrylic acid, poly (meth) acrylic acid salt, sodium alginate and cellulose derivatives.

7. Use of a catalyst prepared by the method for preparing a catalyst according to any one of claims 1 to 6 in VOC oxidation.

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