Selective oxidation catalyst and preparation method thereof
By using a selective oxidation catalyst with support and supported active components in the treatment of organic amine exhaust gas, the problem of low N2 selectivity in the prior art is solved, and efficient selective oxidation of organic amine exhaust gas and inhibition of nitrogen-containing by-products is achieved.
Patent Information
- Application Number
- CN202311666142.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-06
- Publication Date
- 2025-06-06
AI Technical Summary
The prior art has the problem of low N2 selectivity in the treatment of organic amine exhaust gas, and it is difficult to achieve efficient selective oxidation and inhibition of nitrogen-containing by-products.
Using a selective oxidation catalyst comprising a support and an active component supported on the support, the active component including a first active component (such as an oxide of Ni, Pd, Pt), a second active component (such as an oxide of V, Cu, Fe, Mn), a support (such as an oxide of Ti, Al, Si) and an additive (such as an oxide of Ce, Mo, W), the performance of the catalyst is improved by specific component combinations and preparation methods.
At the same temperature, the conversion rate and N2 selectivity of the catalyst are significantly improved, the performance of the catalyst is improved, and the efficient selective oxidation of organic amine exhaust gas and effective inhibition of nitrogen-containing by-products are achieved.
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Figure CN120094579A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of selective oxidation catalysts, and in particular to a selective oxidation catalyst and a preparation method thereof. Background Art
[0002] Nitrogen-containing volatile organic compounds (NVOCs) often have pungent odors such as foul smells and are one of the important regulatory parameters for achieving emission standards. There are many types of NVOCs, among which organic amines are commonly used as raw materials in industrial production processes. They have a serious nuisance odor and can cause serious harm to the environment and human health.
[0003] In the early stage of domestic treatment of organic amine waste gas, incineration treatment or coupling with other organic waste gas treatment was mainly adopted. However, due to the presence of nitrogen atoms, the process of catalytic decomposition of organic amines is quite complicated. The process involves the mutual conversion of multiple pollutants and inevitably forms NH 3 、NO x Therefore, it is of great significance to develop suitable catalytic materials, develop new catalytic combustion technologies, and simultaneously achieve efficient selective oxidation of organic amine waste gas and inhibition of nitrogen-containing by-products, thereby achieving efficient purification. Summary of the invention
[0004] The purpose of the present invention is to overcome the existing N 2 To solve the problem of low selectivity, a selective oxidation catalyst with high selectivity and high catalytic activity and a preparation method thereof are provided.
[0005] The inventors of the present invention have found through a large number of experiments that in the selective oxidation of NVOCs, although noble metal-based catalysts such as Pt and Pd have strong oxidizing ability and can basically achieve complete oxidation of organic amines, they will peroxidize nitrogen-containing groups to generate NO. x , resulting in lower N 2 Selectivity; transition metal catalysts such as Mn, Cu, Co, and Ni can better control the N content of the product. 2 The selective oxidation catalyst provided by the present invention can ensure a better conversion rate and improve N 2 Selectivity further improves the performance of the catalyst.
[0006] In order to achieve the above-mentioned object, the first aspect of the present invention provides a selective oxidation catalyst, which comprises a carrier and an active component supported on the carrier, wherein the active component comprises a first active component, a second active component and an auxiliary agent, the first active component is selected from one or more metal oxides of Ni, Pd and Pt, the second active component is selected from one or more metal oxides of V, Cu, Fe and Mn, the carrier is selected from one or more metal oxides of Ti, Al and Si, and the auxiliary agent is selected from one or more metal oxides of Ce, Mo and W.
[0007] Based on the weight of the carrier, the loading amount of the first active ingredient is 0.1-3% by weight, the loading amount of the second active ingredient is 0.5-2% by weight, and the loading amount of the auxiliary agent is 8-12% by weight.
[0008] Preferably, the first active component is selected from NiO, PdO, PtO 2 One or more of .
[0009] Preferably, the second active component is selected from V 2 O 5 , CuO, Fe 2 O 3 and MnO 2 One or more of .
[0010] Preferably, the carrier is selected from TiO 2 、Al 2 O 3 and SiO 2 One or more of .
[0011] Preferably, the auxiliary agent is selected from CeO 2 、MoO 3 and WO 3 One or more of .
[0012] Preferably, the loading amount of the first active ingredient is 0.5-2% by weight.
[0013] Preferably, based on the weight of the carrier, the loading amount of the second active ingredient is 1-2 wt%.
[0014] Preferably, the loading amount of the auxiliary agent is 9-11 wt % based on the weight of the carrier.
[0015] Preferably, the catalyst carrier is TiO 2 The first active component is PdO, and the second active component is V 2 O 5 , the auxiliary agent is WO 3 .
[0016] Preferably, based on the weight of the carrier, the loading amount of the first active ingredient is 0.5-1.5% by weight, the loading amount of the second active ingredient is 1-1.5% by weight, and the loading amount of the auxiliary agent is 9.5-10.5% by weight.
[0017] A second aspect of the present invention provides a method for preparing a selective oxidation catalyst, characterized in that the method comprises the following steps:
[0018] 1) In the presence of water, a solution containing a first active component precursor, a solution containing a second active component precursor, and an auxiliary agent precursor are first mixed to obtain a first mixed product;
[0019] 2) a step of mixing the first mixed product obtained in step 1) with a carrier to obtain a second mixed product;
[0020] 3) the step of roasting the second mixed product obtained in step 2),
[0021] The first active component precursor is selected from one or more nitrates of Ni, Pd and Pt, the second active component precursor is selected from compounds containing one or more elements of V, Cu, Fe and Mn, the carrier is selected from oxides of one or more metals of Ti, Al and Si, and the auxiliary agent precursor is selected from compounds containing one or more elements of Ce, Mo and W.
[0022] Based on the weight of the carrier, the amount of the first active ingredient precursor calculated as metal element is 0.1-3% by weight, the amount of the second active ingredient precursor calculated as metal oxide is 0.5-2% by weight, and the amount of the auxiliary agent precursor calculated as metal oxide is 8-12% by weight.
[0023] Preferably, the first active component precursor is palladium nitrate.
[0024] Preferably, the second active component precursor is selected from one or more of ammonium metavanadate, copper nitrate, iron nitrate and manganese nitrate, preferably ammonium metavanadate.
[0025] Preferably, the carrier is selected from TiO 2 、SiO 2 and Al 2 O 3 One or more of, preferably TiO 2 .
[0026] Preferably, the auxiliary agent precursor is selected from one or more of ammonium metatungstate, ammonium molybdate and cerium nitrate, more preferably ammonium metatungstate.
[0027] Preferably, the amount of the first active ingredient precursor calculated as metal is 0.5-2 wt % based on the weight of the carrier.
[0028] Preferably, the amount of the second active ingredient precursor calculated as metal oxide is 1-2 wt % based on the weight of the carrier.
[0029] Preferably, the amount of the auxiliary agent precursor calculated as metal oxide is 9-11 wt % based on the weight of the carrier.
[0030] Preferably, the catalyst carrier is TiO 2 The first active component precursor is palladium nitrate, the second active component precursor is ammonium metavanadate, and the auxiliary agent precursor is ammonium metatungstate.
[0031] Preferably, based on the weight of the carrier, the amount of the first active ingredient precursor calculated as a metal element is 0.5-1.5 weight %, the amount of the second active ingredient calculated as a metal oxide is 1-1.5 weight %, and the amount of the auxiliary agent calculated as a metal oxide is 9.5-10.5 weight %.
[0032] Preferably, the mass ratio of the carrier to the first mixed product is 1:10-16.
[0033] Preferably, the mass ratio of the carrier to the first mixed product is 1:12-14.
[0034] Preferably, before the roasting, the method further comprises a step of drying the second mixed product.
[0035] Preferably, in step 3), the calcination conditions include: temperature of 400-600° C. and time of 2-8 h. BRIEF DESCRIPTION OF THE DRAWINGS
[0036] Figure 1 It is a curve chart showing the change of the total non-methane hydrocarbon conversion rate of the catalyst shown in Example 1 as a function of the reaction temperature. DETAILED DESCRIPTION
[0037] The endpoints and any values of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of each range, the endpoint values of each range and the individual point values, and the individual point values can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.
[0038] A first aspect of the present invention provides a selective oxidation catalyst, which contains a carrier and an active component loaded on the carrier, characterized in that the active component includes a first active component, a second active component and an auxiliary agent, the first active component is selected from one or more metal oxides of Ni, Pd and Pt, the second active component is selected from one or more metal oxides of V, Cu, Fe and Mn, the carrier is selected from one or more metal oxides of Ti, Al and Si, and the auxiliary agent is selected from one or more metal oxides of Ce, Mo and W. Based on the weight of the carrier, the loading amount of the first active component is 0.1-3% by weight, the loading amount of the second active component is 0.5-2% by weight, and the loading amount of the auxiliary agent is 8-12% by weight.
[0039] In the present invention, the specific combination of catalyst components can not only improve the catalytic performance of the catalyst, but also significantly increase the N 2 Selectivity, while achieving efficient selective oxidation of organic amine waste gas and suppression of nitrogen-containing by-products, thereby achieving its efficient purification.
[0040] According to the present invention, the first active component can be used as an oxidation active component of the catalyst to increase N 2 Selectivity and catalyst performance, preferably, the first active component is selected from NiO, PdO, PtO 2 One or more; more preferably, the first active component is PdO.
[0041] According to the present invention, the second active component can be used as a reduction active component of the catalyst to increase N 2 Selectivity and catalyst performance, preferably, the second active component is selected from V 2 O 5 , CuO, Fe 2 O 3 、MnO 2 More preferably, the second active group is V 2 O 5 .
[0042] According to the present invention, in order to increase N 2 Selectivity and catalyst performance, preferably, the carrier is selected from TiO 2 、SiO 2 and Al 2 O 3 More preferably, the carrier is TiO 2 .
[0043] According to the present invention, in order to increase N 2Selectivity and catalyst performance, preferably, the auxiliary agent is selected from CeO 2 、MoO 3 and WO 3 More preferably, the auxiliary agent is WO 3 .
[0044] In the present invention, by using a catalyst containing the above components, the performance of the catalyst is significantly improved, and at the same temperature, a better conversion rate can be ensured while increasing N 2 choose.
[0045] According to the present invention, in order to increase N 2 Selectivity and catalyst performance, preferably, based on the weight of the carrier, the loading amount of the first active ingredient is 0.5-2 weight %.
[0046] According to the present invention, in order to increase N 2 Selectivity and catalyst performance, preferably, the loading amount of the second active ingredient is 1-2 wt % based on the weight of the carrier.
[0047] According to the present invention, in order to increase N 2 Selectivity and catalyst performance, preferably, the loading amount of the auxiliary agent is 9-11% by weight based on the weight of the carrier.
[0048] According to the present invention, in order to obtain N 2 The catalyst with the highest selectivity and the best catalytic oxidation performance is preferably a carrier of TiO 2 The first active component is Pd, and the second active component is V 2 O 5 , the auxiliary agent is WO 3 .
[0049] According to the present invention, in order to obtain N 2 The catalyst with the highest selectivity and the best catalytic oxidation performance can be further limited in terms of the content of its components based on the selection of the components. Preferably, the loading amount of the first active ingredient is 0.5-1.5 weight %; the loading amount of the second active ingredient is 1-1.5 weight % based on the weight of the carrier; and the loading amount of the auxiliary agent is 9.5-10.5 weight % based on the weight of the carrier.
[0050] In a second aspect of the present invention, a method for preparing the selective oxidation catalyst according to the first aspect of the present invention is provided, wherein the method comprises the following steps:
[0051] 1) In the presence of water, a solution containing a first active component precursor, a solution containing a second active component precursor, and an auxiliary agent precursor are first mixed to obtain a first mixed product;
[0052] 2) a step of mixing the first mixed product obtained in step 1) with a carrier to obtain a second mixed product;
[0053] 3) the step of roasting the second mixed product obtained in step 2),
[0054] The first active component precursor is selected from one or more nitrates of Ni, Pd and Pt, the second active component precursor is selected from compounds containing one or more elements of V, Cu, Fe and Mn, the carrier is selected from oxides of one or more metals of Ti, Al and Si, and the auxiliary agent precursor is selected from compounds containing one or more elements of Ce, Mo and W.
[0055] Based on the weight of the carrier, the amount of the first active ingredient precursor calculated as metal element is 0.1-3% by weight, the amount of the second active ingredient precursor calculated as metal oxide is 0.5-2% by weight, and the amount of the auxiliary agent precursor calculated as metal oxide is 8-12% by weight.
[0056] According to the second aspect of the present invention, the nitrate may be, for example, one or more of nickel nitrate, palladium nitrate and platinum nitrate, preferably palladium nitrate.
[0057] According to the second aspect of the present invention, the second active component precursor may be, for example, one or more of ammonium metavanadate, copper nitrate, iron nitrate and manganese nitrate, preferably ammonium metavanadate.
[0058] According to the second aspect of the present invention, the carrier may be, for example, TiO 2 、SiO 2 and Al 2 O 3 One or more of, preferably TiO 2 .
[0059] According to the second aspect of the present invention, the auxiliary agent precursor may be, for example, one or more of ammonium metatungstate, ammonium molybdate and cerium nitrate, preferably ammonium metatungstate.
[0060] The types of the first active component, the second active component, the auxiliary agent and the carrier are as described above and will not be described in detail here.
[0061] In the present invention, the water is not particularly limited, and is preferably deionized water. For example, the water may account for 97-99% by weight of the first mixed product.
[0062] In the present invention, since it is only necessary to completely dissolve the first active component and the second active component in the solution, the amount of the solution required is not particularly limited, and water is preferably used for dissolution. In order to avoid a long evaporation time, the concentration of the solution containing the first active component precursor can be 0.8-1.0 g / L; the concentration of the solution containing the second active component precursor can be 1.0-1.2 g / L.
[0063] According to the present invention, in order to increase N 2 Selectivity and catalyst performance, preferably, based on the weight of the carrier, the content of the first active component is 0.5-2% by weight of the carrier.
[0064] According to the present invention, in order to increase N 2 Selectivity and catalyst performance, preferably, based on the weight of the carrier, the content of the second active component is 1-2 weight % of the carrier.
[0065] According to the present invention, in order to increase N 2 Selectivity and catalyst performance, preferably, based on the weight of the carrier, the content of the additive is 9-11% by weight of the carrier.
[0066] For the first mixing, the mixing can be carried out by a commonly used method in the art, and there is no particular limitation on this. It is only necessary to uniformly mix the solution of the first active component precursor, the solution containing the second active component precursor, and the auxiliary agent precursor. For example, the mixing temperature can be 5-45° C., preferably 10-35° C., and the mixing time is not limited, for example, it can be 1-30 minutes, preferably 1-10 minutes.
[0067] The second mixing is the same as the first mixing, and it is only necessary to mix the first mixed product and the carrier uniformly.
[0068] According to the present invention, in order to obtain N 2 The catalyst with the best selectivity and performance is preferably a carrier of TiO 2 The first active component precursor is palladium nitrate, the second active component precursor is ammonium metavanadate, and the auxiliary agent precursor is ammonium metatungstate.
[0069] According to the present invention, in order to obtain N 2 The catalyst with the best selectivity and performance is preferably composed of 0.5-1.5 wt % of the first active ingredient precursor as a metal element, 1-1.5 wt % of the second active ingredient as a metal oxide, and 9.5-10.5 wt % of the additive as a metal oxide, based on the weight of the carrier.
[0070] In a preferred embodiment of the present invention, the temperature of the second mixing may be 30-90° C., preferably 60-80° C., and the mixing time is not particularly limited. In order to reduce the workload of drying, it is preferred that the solvent is fully evaporated during the second mixing.
[0071] According to the present invention, in order to obtain N 2 A catalyst with the highest selectivity and better catalytic oxidation performance, in step 2), wherein the mass ratio of the carrier to the first mixed product is 1:10-16; more preferably, the mass ratio of the carrier to the first mixed product is 1:12-14.
[0072] According to the present invention, in order to remove the solvent remaining in the second mixed product, the second mixed product is preferably dried before the calcination.
[0073] Preferably, the drying conditions include: a temperature of 70-150° C. and a time of 8 h to 24 h; more preferably, the drying conditions include: a temperature of 90-120° C. and a time of 10-14 h.
[0074] According to the present invention, in order to improve the stability of the chemical properties of the catalyst, in step 3), preferably, the calcination conditions include: temperature of 400-600°C, time of 2-8h; more preferably, the calcination conditions include: temperature of 510-560°C, time of 3-5h.
[0075] The present invention will be described in detail below by way of examples, but the present invention is not limited to the following examples.
[0076] In the following examples, unless otherwise specified, the raw materials used are conventional commercial products or prepared by conventional methods.
[0077] Figure 1 Measured by Testo350 flue gas analyzer (purchased from Testo).
[0078] Example 1
[0079] 1) According to V 2 O 5 and WO 3 The loading amounts of TiO 2 1.5wt% and 10wt% of ammonium metavanadate and ammonium metatungstate are weighed and dissolved in 60mL of deionized water to prepare a mixed solution of ammonium metavanadate and ammonium metatungstate, and 1.5mL of palladium nitrate solution is added to the above solution;
[0080] 2) Stir well and slowly add TiO 2 Carrier powder, TiO 2The mass ratio of the carrier to the product of step 1) is 1:13, and then the temperature is raised to 80° C. and stirred until the solution is evaporated to dryness;
[0081] 3) The obtained wet material was placed in an oven for drying at 110° C. for 12 h, and then calcined in a muffle furnace at 550° C. for 4 h to obtain catalyst S1.
[0082] The curve of the non-methane total hydrocarbon conversion rate of catalyst S1 changing with the reaction temperature is shown in Figure 1 shown.
[0083] Example 2
[0084] The steps are the same as those in Example 1, except that:
[0085] In step 1), 0.5 mL of palladium nitrate solution was added to prepare catalyst S2.
[0086] Example 3
[0087] The steps are the same as those in Example 1, except that:
[0088] In step 1), 2 mL of palladium nitrate solution was added to prepare catalyst S3.
[0089] Example 4
[0090] The steps are the same as those in Example 1, except that:
[0091] In step 1), according to V 2 O 5 and WO 3 The loading amounts of TiO 2 2wt% and 10wt% of the mass were weighed to prepare catalyst S4.
[0092] Example 5
[0093] The steps are the same as those in Example 1, except that:
[0094] In step 1), according to V 2 O 5 and WO 3 The loading amounts of TiO 2 1.0 wt% and 10 wt% of the mass were weighed, and 1.0 mL of palladium nitrate solution was added to prepare catalyst S5.
[0095] Comparative Example 1
[0096] The steps are the same as those in Example 1, except that:
[0097] In step 2), the loading amount of CuO is TiO 25wt% of the mass, add copper nitrate pentahydrate to the above solution, stir evenly and then slowly add TiO 2 Carrier powder was prepared to obtain catalyst D1.
[0098] Comparative Example 2
[0099] The steps are the same as those in Example 1, except that:
[0100] In step 2), according to MnO 2 The loading amount of TiO 2 5wt% of mass, add manganese nitrate to the above solution, stir evenly and then slowly add TiO 2 Carrier powder to obtain catalyst D2.
[0101] Comparative Example 3
[0102] The steps are the same as those in Example 1, except that:
[0103] In step 2), according to Co 3 O 4 The loading amount of TiO 2 5wt% of mass, add manganese nitrate to the above solution, stir evenly and then slowly add TiO 2 Carrier powder to obtain catalyst D3.
[0104] Test Case
[0105] Catalytic performance test
[0106] The performance evaluation of the organic amine selective oxidation catalyst in the present invention was carried out in a quartz tube with an inner diameter of 4 mm, and the reactant was ethylenediamine at a concentration of 1000 mg / cm 3 , airspeed is 100000h -1 , H 2 The O content is 5%, and the measurement temperature is the temperature at which the gas enters the catalyst bed. The activity of the catalyst is measured by the lowest reaction temperature T at which the ethylenediamine conversion rate reaches 98%. 98 To indicate that N 2 Selective analysis of NO detected after catalytic combustion of ethylenediamine x Concentration (ppm) and all N atoms in ethylenediamine are converted to NO x The calculation formula is: N 2 Selectivity = (1-measured NO x Concentration / theoretical NO x concentration)*100%, as shown in Table 1.
[0107] Table 1
[0108] catalyst <![CDATA[T 98 (℃)]]> <![CDATA[N 2 Selectivity (%)]]> S1 365 99.85 S2 398 97.78 S3 388 97.03 S4 395 99.64 S5 340 99.15 D1 410 94.81 D2 470 86.85 D3 513 92.99
[0109] From Table 1, it can be seen that S1-S5 can completely convert the organic amine at a lower temperature than D1-D3 and has higher N 2 The selectivity shows that the performance of the catalyst of the present invention is significantly improved. At the same temperature, it can ensure a better conversion rate while increasing N 2 Selective.
[0110] pass Figure 1 It can be seen that Example 1 exhibits excellent catalytic oxidation activity of ethylenediamine. When the reaction temperature reaches 365° C., the conversion rate of ethylenediamine reaches 98%.
[0111] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.
Claims
1. A selective oxidation catalyst comprising a carrier and an active component supported on the carrier, It is characterized in that The active components include a first active component, a second active component and an auxiliary agent, the first active component is selected from one or more metal oxides of Ni, Pd and Pt, the second active component is selected from one or more metal oxides of V, Cu, Fe and Mn, the carrier is selected from one or more metal oxides of Ti, Al and Si, and the auxiliary agent is selected from one or more metal oxides of Ce, Mo and W. Based on the weight of the carrier, the loading amount of the first active ingredient is 0.1-3% by weight, the loading amount of the second active ingredient is 0.5-2% by weight, and the loading amount of the auxiliary agent is 8-12% by weight.
2. The catalyst according to claim 1, in, The first active component is selected from NiO, PdO, PtO 2 One or more of; Preferably, the second active component is selected from V 2 O 5 , CuO, Fe 2 O 3 and MnO 2 One or more of; Preferably, the carrier is selected from TiO 2 、Al 2 O 3 and SiO 2 One or more of; Preferably, the auxiliary agent is selected from CeO 2 、MoO 3 and WO 3 One or more of .
3. The catalyst according to claim 1, in, The loading amount of the first active ingredient is 0.5-2% by weight based on the weight of the carrier; Preferably, the loading amount of the second active ingredient is 1-2 wt % based on the weight of the carrier; Preferably, the loading amount of the auxiliary agent is 9-11 wt % based on the weight of the carrier.
4. The catalyst according to any one of claims 1 to 3, in, The catalyst carrier is TiO 2 The first active component is PdO, and the second active component is V 2 O 5 , the auxiliary agent is WO 3 ; Preferably, based on the weight of the carrier, the loading amount of the first active ingredient is 0.5-1.5% by weight, the loading amount of the second active ingredient is 1-1.5% by weight, and the loading amount of the auxiliary agent is 9.5-10.5% by weight.
5. A method for preparing a selective oxidation catalyst, It is characterized in that The method comprises the following steps: 1) In the presence of water, a solution containing a first active component precursor, a solution containing a second active component precursor, and an auxiliary agent precursor are first mixed to obtain a first mixed product; 2) a step of mixing the first mixed product obtained in step 1) with a carrier to obtain a second mixed product; 3) the step of roasting the second mixed product obtained in step 2), The first active component precursor is selected from one or more nitrates of Ni, Pd and Pt, the second active component precursor is selected from compounds containing one or more elements of V, Cu, Fe and Mn, the carrier is selected from oxides of one or more metals of Ti, Al and Si, and the auxiliary agent precursor is selected from compounds containing one or more elements of Ce, Mo and W. Based on the weight of the carrier, the amount of the first active ingredient precursor calculated as metal element is 0.1-3% by weight, the amount of the second active ingredient precursor calculated as metal oxide is 0.5-2% by weight, and the amount of the auxiliary agent precursor calculated as metal oxide is 8-12% by weight.
6. The preparation method according to claim 5, in, The first active component precursor is palladium nitrate; Preferably, the second active component precursor is selected from one or more of ammonium metavanadate, copper nitrate, iron nitrate and manganese nitrate, preferably ammonium metavanadate; Preferably, the carrier is selected from TiO 2 、SiO 2 and Al 2 O 3 One or more of, preferably TiO 2 ; Preferably, the auxiliary agent precursor is selected from one or more of ammonium metatungstate, ammonium molybdate and cerium nitrate, more preferably ammonium metatungstate.
7. The preparation method according to claim 5, in, The amount of the first active ingredient precursor calculated as metal is 0.5-2% by weight based on the weight of the carrier; Preferably, the amount of the second active ingredient precursor calculated as metal oxide is 1-2 wt % based on the weight of the carrier; Preferably, the amount of the auxiliary agent precursor calculated as metal oxide is 9-11 wt % based on the weight of the carrier.
8. The preparation method according to any one of claims 5 to 7, in, The catalyst carrier is TiO 2 , the first active component precursor is palladium nitrate, the second active component precursor is ammonium metavanadate, and the auxiliary agent precursor is ammonium metatungstate; Preferably, based on the weight of the carrier, the amount of the first active ingredient precursor calculated as a metal element is 0.5-1.5 weight %, the amount of the second active ingredient calculated as a metal oxide is 1-1.5 weight %, and the amount of the auxiliary agent calculated as a metal oxide is 9.5-10.5 weight %.
9. The preparation method according to claim 5, in, The mass ratio of the carrier to the first mixed product is 1:10-16; Preferably, the mass ratio of the carrier to the first mixed product is 1:12-14.
10. The preparation method according to claim 5, in, Prior to the roasting, the method further comprises the step of drying the second mixed product; Preferably, in step 3), the calcination conditions include: temperature of 400-600° C. and time of 2-8 h.