Oxide-modified Pt-Co bimetallic catalyst, preparation method and application thereof to CO oxidation

文档序号：1416723 发布日期：2020-03-13 浏览：18次中文

阅读说明：本技术 氧化物修饰的Pt-Co双金属催化剂和制备方法及其对CO氧化的应用 (Oxide-modified Pt-Co bimetallic catalyst, preparation method and application thereof to CO oxidation ) 是由刘源张斯然张成相安康孙若琳于 2019-11-19 设计创作，主要内容包括：本发明涉及氧化物修饰的Pt-Co双金属催化剂和制备方法及其对CO氧化的应用；催化剂前驱体分子式为La1-yCeyCo1-xPtxO3；负载型铂钴基催化剂,前驱体分子式为La1-yCeyCo1-xPtxO3/SiO2；本发明利用钙钛矿型复合氧化物可以将多种金属离子限域并均匀混合于钙钛矿晶格中的特点,将钙钛矿型复合氧化物担载于大比表面积载体上作为催化剂前驱体；还原后可以得到Pt-Co/La2O3或Pt-Co/La-Ce-O/SiO2,其中氧化物为助剂且在反应过程中与双金属紧密接触；用于一氧化碳氧化的反应,在较低温度可以将一氧化碳完全氧化,且反应过程中表现出较好的稳定性和抗烧结性。(The invention relates to an oxide modified Pt-Co bimetallic catalyst, a preparation method and application thereof to CO oxidation; the molecular formula of the catalyst precursor is La 1‑y Ce y Co 1‑x Pt x O 3 (ii) a The molecular formula of the precursor of the supported platinum-cobalt-based catalyst is La 1‑y Ce y Co 1‑x Pt x O 3 /SiO 2 (ii) a The present invention can use perovskite type composite oxideThe method is characterized in that metal ions are confined and uniformly mixed in perovskite lattices, and perovskite type composite oxides are loaded on a carrier with large specific surface area as a catalyst precursor; after reduction, Pt-Co/La can be obtained 2 O 3 Or Pt-Co/La-Ce-O/SiO 2 Wherein the oxide is an auxiliary agent and is in close contact with the bimetal in the reaction process; the method is used for the reaction of oxidizing carbon monoxide, can completely oxidize the carbon monoxide at a lower temperature, and shows better stability and sintering resistance in the reaction process.)

1. A platinum-cobalt-based catalyst is characterized in that the structural formula is Pt-Co/La-Ce-O, and the molecular formula of a precursor is La_1- _yCe_yCo_1-xPt_xO₃Wherein the value range of x is 0.01-0.17, and the value range of y is 0-0.25.

2. The catalyst of claim 1, wherein the Pt-Co/La-Ce-O is supported on SiO as a carrier₂The structural formula is Pt-Co/La-Ce-O/SiO₂The molecular formula of the precursor is La_1-yCe_yCo_1-xPt_xO₃/SiO₂，La_1-yCe_yCo_1-xPt_xO₃The mass fraction in the catalyst is 5.0-20.0%.

3. The method for preparing the catalyst of claim 1, comprising the steps of:

(1) preparing a solution according to the molar ratio of lanthanum nitrate, cerium nitrate, cobalt nitrate, platinum nitrate, citric acid and ethylene glycol (1-0.75), 0-0.25, 0.99-0.83, 0.01-0.17 and 2.4-0.48.

(2) And (2) stirring the solution prepared in the step (1) in a water bath kettle at the temperature of 60-90 ℃ until sol is formed, and obtaining an intermediate product.

(3) And (3) transferring the intermediate product obtained in the step (2) to a constant-temperature drying box for drying to obtain a dried product.

(4) Roasting the product obtained in the step (3) at 250-350 ℃, and then roasting at 550-750 ℃ to obtain a catalyst precursor La_1-yCe_yCo_1-xPt_xO₃Has a perovskite-type composite oxide structure.

(5) Placing the catalyst precursor obtained in the step (4) into a reactor, introducing reduction reaction gas into the reactor, and reducing the catalyst precursor; the temperature is 550-650 ℃; the catalyst Pt-Co/La-Ce-O is obtained.

4. The method for preparing the catalyst of claim 2, comprising the steps of:

(2) Soaking the solution prepared in the step (1) in SiO in the same volume₂And standing the carrier for 12-48 h, and then drying the carrier in a constant-temperature drying oven at the temperature of 60-90 ℃ for 3-8 h to obtain an intermediate product.

(3) And (3) transferring the intermediate product obtained in the step (2) to a constant-temperature drying box for drying to obtain a dried product.

(4) Roasting the product obtained in the step (3) at 250-350 ℃, and then roasting at 550-750 ℃ to obtain a catalyst precursor La_1-yCe_yCo_1-xPt_xO₃/SiO₂。

5. The method for preparing the catalyst according to claim 1 or 2, wherein the intermediate product in the step (3) is transferred to a constant temperature drying oven for drying for 6-24 hours at 100-150 ℃.

6. The method for preparing the catalyst according to claim 1 or 2, wherein the step (4) is performed by roasting at 250-350 ℃ for 1-3 h; roasting at 550-750 ℃ for 4-6 h.

7. The method for preparing the catalyst according to claim 1 or 2, wherein 10000 to 15000 ml/(g) is introduced in the step (5)_cath) The reduction reaction gas is reduced for 1-3 h; the heating rate of 550-650 ℃ is 2-10 ℃/min; .

8. The use of the catalyst for the oxidation of carbon monoxide as claimed in claim 1 or 2, wherein the catalyst is introduced into a reactor at a temperature of 50 to 400 ℃ and a pressure of one atmosphere, and a volume space velocity of 15000 to 36000 ml/(g/g) is introduced into the reactor_cath) Carbon monoxide, oxygen and nitrogen.

9. The method according to claim 8, wherein the molar ratio of carbon monoxide to oxygen to nitrogen is 0.1-2: 99.8-96.

Technical Field

The invention relates to a novel oxide-modified Pt-Co nano bimetallic catalyst taking perovskite type composite oxide as a precursor to be in close contact, and preparation and application thereof in carbon monoxide oxidation, belonging to the application field of metal catalysts.

Background

CO is a common toxic and harmful gas in the atmosphere, mainly resulting from incomplete combustion of fossil fuels. It is a colorless and odorless gas, has a density close to that of air, is easy to spread, and has a boiling point of-191.5 ℃ and a melting point of-205.02 ℃. After being inhaled by a human body, CO is very easy to combine with hemoglobin in blood, so that the hemoglobin cannot combine with oxygen, and the hemoglobin is prevented from transporting oxygen, so that the human body is difficult to breathe, anoxic and dead, and has irreversible damage to the brain of the human body. It is reported that long term exposure to CO concentrations of less than 25ppm/8 hours, or 50ppm/4 hours, can lead to death in 1-3 minutes if exposed to an atmosphere containing a CO concentration of 12800 ppm. The CO poisoning is difficult to detect, so the potential hazard to human bodies is very large, and the threat of even low-concentration CO to human health is not negligible.

However, as industrialization has progressed, CO emissions have increased, and therefore, CO control and elimination have been reluctant. Physical elimination and chemical elimination are common methods of CO elimination. The physical elimination method comprises a membrane separation method and an adsorption method, but because polymer molecules are not resistant to high temperature, the selectivity of a common adsorbent is relatively poor, the efficiency is low, and the cost is high, so the physical elimination method has great limitation in practical industrial application. The chemical elimination method mainly comprises a CO methanation method and a CO catalytic oxidation method. The CO methanation method is carried out by CO and H₂The reaction generates methane or lower alcohol, but the technical requirement is high, so that the method is only stopped at the basic research stage of a laboratory at present, and the method is difficult to be practically applied to the removal of low-concentration CO. The CO catalytic oxidation method takes a catalyst as a medium, so that low-concentration CO reacts with oxygen in the air under mild conditions to generate nontoxic carbon dioxide, is one of the most fundamentally effective methods, has high energy utilization rate and low energy consumption, and is widely applied to tail gas purification of motor vehicles and CO purification₂Laser gas purification, gas mask purification devices, cigarette smoke harm reduction, indoor air environment and closed space operation (submarines, spacecrafts, underground works, underground lifeboats, underground garages) and the like. In conclusion, the CO catalytic oxidation method is more efficient, economical and practical for eliminating low-concentration CO in the air. Therefore, designing and synthesizing new materials, researching and developing high-efficiency, low-consumption and stable catalysts have profound significance for eliminating CO.

At present, the catalysts used for the CO oxidation reaction mainly include noble metal catalysts (such as Pt, Pd, Au, etc.) and non-noble metal catalysts (such as Cu, CO, Mn, etc.).

Gold catalysts in noble metal catalysts have better activity for low temperature oxidation when their particles are small (typically less than 5nm), but are also easily deactivated. The catalytic activity of the platinum-based and palladium-based catalysts loaded on the carrier is obviously higher than that of the unsupported metals Pd and Pt. However, such simple supported noble metal catalysts often need to react at a relatively high temperature to have the desired catalytic carbon monoxide oxidation activity and are volatile. The inactivation is caused by the accumulation of carbonate on the surface of the catalyst; secondly, the noble metal particles are aggregated. In addition, the precious metals such as Au, Pt and Pd have limited reserves, higher price and limited application cost. Therefore, it is necessary to reduce the content of noble metals and improve the activity of the catalyst by adding a small amount of rare earth metals or transition metals as an auxiliary. It has been found that the addition of a number of metals or metal oxides is effective in increasing the catalytic activity of the noble metal supported catalyst. Thormahlen et al found Pt/A1 with addition of a certain amount of promoter₂O₃The catalyst has obviously higher activity and stability. But Pt and the auxiliary CoO_xCan not be in close contact with each other and is activatedAnd (4) limiting.

The non-noble metal catalyst mainly comprises a single metal oxide catalyst and a composite metal oxide catalyst. Many metal oxides have a promoting effect on catalyzing CO oxidation, and are mainly concentrated on transition metal oxides and rare earth elements. But the performance of non-noble metals is generally inferior compared to noble metals.

Thus combining noble metals with non-noble metals can increase activity and reduce cost. For example, the Co-Pt-based bimetallic nanoparticles prepared by simultaneously loading transition metal Co on the basis of the supported Pt-based catalyst can effectively improve the catalytic performance of the catalyst. Wang et al prepared CNTs loaded Pt-Co bimetallic catalyst Pt-Co/CNTs for H₂CO is preferentially oxidized in the atmosphere, and the addition of Co element is found to remarkably improve the catalytic performance of the catalyst Pt/CNTs, which shows that the combination of bimetal can effectively improve the performance of the catalyst, and for the Pt-Co bimetal catalyst, the auxiliary agent has great influence on the activity of the Pt-Co bimetal catalyst, and the auxiliary agent is required to be in close contact with bimetal, so that the preparation difficulty is further increased, and no proper preparation method is available at present to realize the close combination of the auxiliary agent and bimetal nano particles, so that the activity of the catalyst is improved.

Therefore, the novel close-contact oxide modified Pt-Co-based CO oxidation catalyst system explored by the invention has important application value.

The perovskite type composite oxide (PTO) has a body-centered cubic structure and the composition can be written as ABO₃Wherein the A site is a rare earth element, an alkaline earth element, an alkali element or Bi occupying the apex of the cubic unit cell³⁺、Pb²⁺And the B site is a transition metal element having catalytic activity occupying the center of an oxygen octahedron. The method is characterized by mainly comprising the following aspects: (1) adjustable denaturation of composition and structure. As most metal ions in the periodic table of elements can be used as A site or B site ions of crystal lattices of the periodic table of elements, and the A site and/or B site ions can be partially replaced by other ions, metal ions of proper types can be selected according to the needs of researchers, so that the perovskite type composite oxide with the required composition is obtained; (2) homogeneous mixing at the atomic level. All metal ions are in atomic formUniformly distributed in the perovskite lattice, so that the reduced components can be in close contact, which is favorable for the interaction among the reduced ions; (3) and (4) a domain limiting effect. All metal ions in the perovskite are confined to the perovskite lattice and the components of the reduced catalyst will then be in intimate contact. Therefore, by utilizing the characteristics of the perovskite structure and taking PTOs as a precursor, the supported catalyst with close contact of the bimetal and the auxiliary agent can be prepared.

Disclosure of Invention

The invention aims to provide a novel oxide-modified Pt-Co nano bimetallic catalyst taking a perovskite type composite oxide as a precursor, and a preparation method and application thereof. The catalyst can be used for CO oxidation and has better activity, stability and anti-sintering performance.

The technical scheme of the invention is as follows:

a platinum-cobalt-based catalyst has a structural formula of Pt-Co/La-Ce-O and a precursor molecular formula of La_1-yCe_yCo_1- _xPt_xO₃Wherein the value range of x is 0.01-0.17, and the value range of y is 0-0.25.

A Pt-Co based catalyst with a structural formula of Pt-Co/La-Ce-O/SiO₂Precursor La_1-yCe_yCo_1-xPt_xO₃SiO carried on carrier₂The molecular formula of the precursor is La_1-yCe_yCo_1-xPt_xO₃/SiO₂Wherein the value range of x is 0.01-0.17, and the value range of y is 0-0.25. La_1-yCe_yCo_1-xPt_xO₃The mass fraction in the catalyst is 5.0-20.0%.

In the prepared catalyst, the assistant La₂O₃、CeO₂Bimetallic Pt and Co are in intimate contact.

The preparation method of the catalyst Pt-Co/La-Ce-O comprises the following steps:

(2) And (2) stirring the solution prepared in the step (1) in a water bath kettle at the temperature of 60-90 ℃ until sol is formed, and obtaining an intermediate product.

(3) And (3) transferring the intermediate product obtained in the step (2) to a constant-temperature drying box for drying to obtain a dried product.

The catalyst Pt-Co/La-Ce-O/SiO₂The preparation method comprises the following steps:

(3) And (3) transferring the intermediate product obtained in the step (2) to a constant-temperature drying box for drying to obtain a dried product.

(4) Roasting the product obtained in the step (3) at 250-350 ℃, and then roasting at 550-750 ℃ to obtain a catalyst precursor La_1-yCe_yCo_1-xPt_xO₃/SiO₂。

In the above preparation method, only the step (2) for supporting the carrier is different, and other steps and conditions are the same, so that the preferred conditions for generalizing other steps are as follows:

and (4) transferring the intermediate product in the step (3) to a constant-temperature drying oven for drying for 6-24 hours at the temperature of 100-150 ℃.

Roasting the obtained product in the step (4) at 250-350 ℃ for 1-3 h; roasting at 550-750 ℃ for 4-6 h.

In the step (5), 10000-15000 ml/(g)_cath) The reduction reaction gas is reduced for 1-3 h; the temperature rise rate of 550-650 ℃ is 2-10 ℃/min.

The reduction reaction gas is hydrogen or carbon monoxide, or one or more inert gases of nitrogen, helium and argon are added into the reduction reaction gas and are used as the reduction gas together with the reduction reaction gas, wherein the volume fraction of the inert gases in the mixed gas is 1-99%.

The catalyst of the invention is Pt-Co/La-Ce-O or Pt-Co/La-Ce-O/SiO₂The method is applied to carbon monoxide oxidation, wherein a catalyst is added into a reactor, and the volume space velocity is 15000-36000 ml/(g) under the conditions that the temperature is 50-400 ℃ and the pressure is one atmosphere_cath) Carbon monoxide, oxygen and nitrogen; the molar ratio of the carbon monoxide to the oxygen to the nitrogen is 0.1-2: 99.8-96.

The invention has the beneficial effects that Pt ions enter the B site of the perovskite compound by using a citric acid complexation method and an isometric impregnation method, and Ce ions enter the A site of the perovskite compound to prepare a series of perovskite structure La_1-yCe_yCo_1-xPt_xO₃Loaded on SiO₂The catalyst precursor is reduced to obtain a series of Co-Pt bimetallic nanoparticles with different proportions. By utilizing the structure of perovskite, the method realizes that a plurality of metal ions of La, Ce, Co and Pt are uniformly mixed and confined in perovskite crystal grains; reduction can obtain Pt-Co/La₂O₃，Pt-Co/La-Ce-O，Pt-Co/La₂O₃/SiO₂Or Pt-Co/La-Ce-O/SiO₂Wherein oxide La₂O₃Or the mixed oxide La-Ce-O is taken as an auxiliary agent, and the auxiliary agent, Co and Pt are in close contact to form a cluster. The catalyst can be usedIn the reaction of carbon monoxide oxidation, carbon monoxide can be completely oxidized at a lower temperature, and the reaction process shows better stability and sintering resistance.

Co-Pt bimetal nanoparticles and oxide La are formed after reduction of catalyst precursor₂O₃Or La-Ce-O, which is very important for the catalyst. After reduction and in the reaction process, the auxiliary agent is closely contacted with the bimetallic Co-Pt and is highly dispersed in SiO of the carrier₂Both of these are the key reasons for the superior performance of the catalyst.

Drawings

FIG. 1: x-ray diffraction (XRD) patterns of catalyst precursors prepared in examples 1-5

FIG. 2: x-ray diffraction (XRD) patterns of the catalysts prepared in examples 16-20

FIG. 3: stability test results for the catalyst prepared in example 19 are shown, with the reaction conditions: the reaction gas composition is 1% CO and 1% O₂And 98 vol% N₂As an equilibrium gas, the reaction temperature was 400 ℃ and the space velocity was 24,000ml g_cat ^-1h^-1

FIG. 4: line scan results of La, Ce, Co, Pt for the catalyst prepared in example 19

Detailed Description

[ example 1 ]

(1) Namely, according to the mole number, lanthanum nitrate: cobalt nitrate: platinum nitrate: citric acid: preparing a solution according to the ratio of 1:0.99:0.01:2.4: 0.48; (2) stirring the solution obtained in the step (1) in a water bath kettle at the temperature of 80 ℃ until sol is formed, and obtaining an intermediate product; (3) transferring the intermediate product obtained in the step (2) to a constant-temperature drying oven to be dried for 12 hours at 120 ℃ to obtain a dried product; (4) respectively roasting the product obtained in the step (3) at 300 ℃ and 600 ℃ for 2h and 5h to obtain a catalyst precursor LaCo_0.99Pt_0.01O₃(ii) a (5) Placing the catalyst precursor obtained in the step (4) into a reactor, and introducing 12000 ml/(g) into the reactor_cath) Reducing the catalyst precursor, wherein the heating rate is 2 ℃/min; the temperature is 600 ℃; the reduction time was 2 h. Obtaining the catalyst Pt-Co/La₂O₃. As shown in fig. 1, (a) in fig. 1 is an X-ray diffraction (XRD) pattern of the catalyst precursor.

Adding a catalyst into a reactor, and introducing 24000 ml/(g) of volume space velocity into the reactor under the conditions that the temperature is 50-400 ℃ and the pressure is 0.1MPa_cath) Wherein the molar ratio of carbon monoxide, oxygen and nitrogen is 1:1: 98.

Under the above conditions, the results of the CO oxidation reaction are as follows:

at 50 ℃, the CO conversion rate is 0%; at 80 ℃, the CO conversion rate is 2 percent; at 110 ℃, the CO conversion rate is 13 percent; at 130 ℃, the CO conversion rate is 25%; at 380 ℃, the CO conversion rate is 100 percent; at 400 ℃, the conversion of CO is 100%.

[ example 2 ]

(1) Namely, according to the mole number, lanthanum nitrate: cobalt nitrate: platinum nitrate: citric acid: preparing a solution according to the ratio of 1:0.89:0.11:2.4: 0.48; (2) stirring the solution obtained in the step (1) in a water bath kettle at the temperature of 80 ℃ until sol is formed, and obtaining an intermediate product; (3) transferring the intermediate product obtained in the step (2) to a constant-temperature drying oven to be dried for 12 hours at 120 ℃ to obtain a dried product; (4) respectively roasting the product obtained in the step (3) at 300 ℃ and 600 ℃ for 2h and 5h to obtain a catalyst precursor LaCo_0.89Pt_0.11O₃(ii) a (5) Placing the catalyst precursor obtained in the step (4) into a reactor, and introducing 12000 ml/(g) into the reactor_cath) Reducing the catalyst precursor, wherein the heating rate is 2 ℃/min; the temperature is 600 ℃; the reduction time was 2 h. Obtaining the catalyst Pt-Co/La₂O₃. As shown in fig. 1, (b) in fig. 1 is an X-ray diffraction (XRD) pattern of the catalyst precursor.

Under the above conditions, the results of the CO oxidation reaction are as follows:

at 50 ℃, the CO conversion rate is 0%; at 80 ℃, the CO conversion rate is 7 percent; at 110 ℃, the CO conversion rate is 18 percent; at 130 ℃, the CO conversion rate is 30 percent; at 360 ℃, the CO conversion rate is 100 percent; at 400 ℃, the conversion of CO is 100%.

[ example 3 ]

(1) Namely, according to the mole number, lanthanum nitrate: cobalt nitrate: platinum nitrate: citric acid: preparing a solution according to the ratio of 1:0.89:0.13:2.4: 0.48; (2) stirring the solution obtained in the step (1) in a water bath kettle at the temperature of 80 ℃ until sol is formed, and obtaining an intermediate product; (3) transferring the intermediate product obtained in the step (2) to a constant-temperature drying oven to be dried for 12 hours at 120 ℃ to obtain a dried product; (4) respectively roasting the product obtained in the step (3) at 300 ℃ and 600 ℃ for 2h and 5h to obtain a catalyst precursor LaCo_0.89Pt_0.11O₃(ii) a (5) Placing the catalyst precursor obtained in the step (4) into a reactor, and introducing 12000 ml/(g) into the reactor_cath) Reducing the catalyst precursor, wherein the heating rate is 2 ℃/min; the temperature is 600 ℃; the reduction time was 2 h. Obtaining the catalyst Pt-Co/La₂O₃. As shown in fig. 1, (c) in fig. 1 is an X-ray diffraction (XRD) pattern of the catalyst precursor.

Under the above conditions, the results of the CO oxidation reaction are as follows:

at 50 ℃, the CO conversion rate is 0%; at 80 ℃, the CO conversion rate is 10 percent; at 110 ℃, the CO conversion rate is 21 percent; at 130 ℃, the CO conversion rate is 35 percent; at 360 ℃, the CO conversion rate is 100 percent; at 400 ℃, the conversion of CO is 100%.

[ example 4 ]

(1) Namely, according to the mole number, lanthanum nitrate: cobalt nitrate: platinum nitrate: citric acid: preparing a solution according to the ratio of 1:0.85:0.15:2.4: 0.48; (2) stirring the solution obtained in the step (1) in a water bath kettle at the temperature of 80 DEG CStirring to form sol to obtain an intermediate product; (3) transferring the product obtained in the step (2) to a constant-temperature drying oven to be dried for 12 hours at 120 ℃ to obtain a dried product; (4) respectively roasting the product obtained in the step (3) at 300 ℃ and 600 ℃ for 2h and 5h to obtain a catalyst precursor LaCo_0.85Pt_0.15O₃(ii) a (5) Placing the catalyst precursor obtained in the step (4) into a reactor, and introducing 12000 ml/(g) into the reactor_cath) Reducing the catalyst precursor, wherein the heating rate is 2 ℃/min; the temperature is 600 ℃; the reduction time was 2 h. Obtaining the catalyst Pt-Co/La₂O₃. As shown in fig. 1, (d) in fig. 1 is an X-ray diffraction (XRD) pattern of the catalyst precursor.

Under the above conditions, the results of the CO oxidation reaction are as follows:

at 50 ℃, the CO conversion rate is 0%; at 80 ℃, the CO conversion rate is 14 percent; at 110 ℃, the CO conversion rate is 25 percent; at 130 ℃, the CO conversion rate is 40 percent; at 360 ℃, the CO conversion rate is 100 percent; at 400 ℃, the conversion of CO is 100%.

[ example 5 ]

(1) Namely, according to the mole number, lanthanum nitrate: cobalt nitrate: platinum nitrate: citric acid: preparing a solution according to the ratio of 1:0.83:0.17:2.4: 0.48; (2) stirring the solution obtained in the step (1) in a water bath kettle at the temperature of 80 ℃ until sol is formed, and obtaining an intermediate product; (3) transferring the product obtained in the step (2) to a constant-temperature drying oven to be dried for 12 hours at 120 ℃ to obtain a dried product; (4) respectively roasting the product obtained in the step (3) at 300 ℃ and 600 ℃ for 2h and 5h to obtain a catalyst precursor LaCo_0.83Pt_0.17O₃(ii) a (5) Placing the catalyst precursor obtained in the step (4) into a reactor, and introducing 12000 ml/(g) into the reactor_cath) Reducing the catalyst precursor, wherein the heating rate is 2 ℃/min; temperature ofThe temperature is 600 ℃; the reduction time was 2 h. Obtaining the catalyst Pt-Co/La₂O₃. As shown in fig. 1, (e) in fig. 1 is an X-ray diffraction (XRD) pattern of the catalyst precursor.

Under the above conditions, the results of the CO oxidation reaction are as follows:

at 50 ℃, the CO conversion rate is 0%; at 80 ℃, the CO conversion rate is 15 percent; at 110 ℃, the CO conversion rate is 30 percent; at 130 ℃, the CO conversion rate is 45 percent; at 360 ℃, the CO conversion rate is 100 percent; at 400 ℃, the conversion of CO is 100%.

[ example 6 ]

(1) Namely, according to the molar ratio of lanthanum nitrate: cobalt nitrate: platinum nitrate: citric acid: preparing a solution according to the ratio of 1:0.99:0.01:2.4: 0.48; (2) namely, soaking the solution prepared in the step (1) in SiO in equal volume according to the mass fraction of the perovskite in the catalyst of 10.78 percent₂Standing the carrier for 24 hours, and then placing the sample in a constant-temperature drying oven to be dried for 6 hours at the temperature of 80 ℃ to obtain an intermediate product; (3) heating the intermediate product obtained in the step (2) to 120 ℃ and drying for 12h to obtain a dried product; (4) respectively roasting the product obtained in the step (3) at 300 ℃ and 600 ℃ for 2h and 5h to obtain a catalyst precursor LaCo_0.99Pt_0.01O₃/SiO₂. (5) Placing the catalyst precursor obtained in the step (4) into a reactor, and introducing 12000 ml/(g) into the reactor_cath) Reducing the catalyst precursor, wherein the heating rate is 2 ℃/min; the temperature is 600 ℃; the reduction time was 2 h. Obtaining the catalyst Pt-Co/La₂O₃/SiO₂.

Adding a catalyst into a reactor, and introducing 24000 ml/(g) of volume space velocity into the reactor under the conditions that the temperature is 50-400 ℃ and the pressure is 0.1MPa_cath) Carbon monoxide, oxygen and nitrogen, wherein the molar ratio of carbon monoxide, oxygen and nitrogenThe molar ratio is 1:1: 98.

Under the above conditions, the results of the CO oxidation reaction are as follows:

at 50 ℃, the CO conversion rate is 0%; at 80 ℃, the CO conversion rate is 10 percent; at 110 ℃, the CO conversion rate is 30 percent; at 130 ℃, the CO conversion rate is 40 percent; at 180 ℃, the CO conversion rate is 100 percent; at 400 ℃, the conversion of CO is 100%.

[ example 7 ]

(1) Namely, according to the molar ratio of lanthanum nitrate: cobalt nitrate: platinum nitrate: citric acid: preparing a solution according to the ratio of 1:0.89:0.11:2.4: 0.48; (2) namely, the prepared solution is immersed in SiO in equal volume according to the mass fraction of the perovskite in the catalyst of 10.78 percent₂Standing the carrier for 24 hours, and then placing the sample in a constant-temperature drying oven to be dried for 6 hours at the temperature of 80 ℃ to obtain an intermediate product; (3) heating the intermediate product obtained in the step (2) to 120 ℃ and drying for 12h to obtain a dried product; (4) respectively roasting the product obtained in the step (3) at 300 ℃ and 600 ℃ for 2h and 5h to obtain a catalyst precursor LaCo_0.89Pt_0.11O₃/SiO₂. (5) Placing the catalyst precursor obtained in the step (4) into a reactor, and introducing 12000 ml/(g) into the reactor_cath) Reducing the catalyst precursor, wherein the heating rate is 2 ℃/min; the temperature is 600 ℃; the reduction time was 2 h. Obtaining the catalyst Pt-Co/La₂O₃/SiO₂。

Under the above conditions, the results of the CO oxidation reaction are as follows:

at 50 ℃, the CO conversion rate is 0%; at 80 ℃, the CO conversion rate is 15 percent; at 110 ℃, the CO conversion rate is 40 percent; at 130 ℃, the CO conversion rate is 80 percent; at 120 ℃, the CO conversion rate is 100 percent; at 400 ℃, the conversion of CO is 100%.

[ example 8 ]

(1) Is pressed immediatelyAccording to the molar ratio of lanthanum nitrate: cobalt nitrate: platinum nitrate: citric acid: preparing a solution according to the ratio of 1:0.87:0.13:2.4:0.48 of ethylene glycol; (2) namely, the prepared solution is immersed in SiO in equal volume according to the mass fraction of the perovskite in the catalyst of 10.78 percent₂On a carrier; standing the obtained sample for 24h, and drying the sample in a constant-temperature drying oven at 80 ℃ for 6h to obtain an intermediate product; (3) heating the product obtained in the step (2) to 120 ℃ and drying for 12h to obtain a dried product; (4) respectively roasting the product obtained in the step (3) at 300 ℃ and 600 ℃ for 2h and 5h to obtain a catalyst precursor LaCo_0.87Pt_0.13O₃/SiO₂. (5) Placing the catalyst precursor obtained in the step (4) into a reactor, and introducing 12000 ml/(g) into the reactor_cath) Reducing the catalyst precursor, wherein the heating rate is 2 ℃/min; the temperature is 600 ℃; the reduction time is 2h, and Pt-Co/La is obtained₂O₃/SiO₂A catalyst.

Under the above conditions, the results of the CO oxidation reaction are as follows:

at 50 ℃, the CO conversion rate is 0%; at 80 ℃, the CO conversion rate is 19 percent; at 110 ℃, the CO conversion rate is 53 percent; at 130 ℃, the CO conversion rate is 85 percent; at 150 ℃, the CO conversion rate is 100 percent; at 400 ℃, the conversion of CO is 100%.

[ example 9 ]

(1) Namely, according to the molar ratio of lanthanum nitrate: cobalt nitrate: platinum nitrate: citric acid: preparing a solution according to the ratio of 1:0.85:0.15:2.4: 0.48; (2) soaking the prepared solution in SiO in equal volume according to the mass fraction of the perovskite in the catalyst of 10.78%₂Standing the carrier for 24 hours, and then drying the carrier in a constant-temperature drying oven at 80 ℃ for 6 hours to obtain an intermediate product; (3) heating the product obtained in the step (2) to 120 ℃ and drying for 12h to obtain a dried product; (4) i.e. byRoasting the product obtained in the step (3) at 300 ℃ and 600 ℃ for 2h and 5h respectively to obtain a catalyst precursor LaCo_0.85Pt_0.15O₃/SiO₂. (5) Placing the catalyst precursor obtained in the step (4) into a reactor, and introducing 12000 ml/(g) into the reactor_cath) Reducing the catalyst precursor, wherein the heating rate is 2 ℃/min; the temperature is 600 ℃; the reduction time is 2h, and Pt-Co/La is obtained₂O₃/SiO₂A catalyst.

Under the above conditions, the results of the CO oxidation reaction are as follows:

at 50 ℃, the CO conversion rate is 0%; at 80 ℃, the CO conversion rate is 21 percent; at 110 ℃, the CO conversion rate is 56 percent; at 130 ℃, the CO conversion rate is 89%; at 140 ℃, the CO conversion rate is 100 percent; at 400 ℃, the conversion of CO is 100%.

[ example 10 ]

(1) Namely, according to the molar ratio of lanthanum nitrate: cobalt nitrate: platinum nitrate: citric acid: preparing a solution according to the ratio of 1:0.83:0.17:2.4: 0.48; (2) soaking the prepared solution in SiO in equal volume according to the mass fraction of the perovskite in the catalyst of 10.78%₂Standing the carrier for 24 hours, and then drying the carrier in a constant-temperature drying oven at 80 ℃ for 6 hours to obtain an intermediate product; (3) heating the product obtained in the step (2) to 120 ℃ and drying for 12h to obtain a dried product; (4) respectively roasting the product obtained in the step (3) at 300 ℃ and 600 ℃ for 2h and 5h to obtain a catalyst precursor LaCo_0.83Pt_0.17O₃/SiO₂. (5) Placing the catalyst precursor obtained in the step (4) into a reactor, and introducing 12000 ml/(g) into the reactor_cath) Reducing the catalyst precursor, wherein the heating rate is 2 ℃/min; the temperature is 600 ℃; the reduction time is 2h, and Pt-Co/La is obtained₂O₃/SiO₂A catalyst.

Under the above conditions, the results of the CO oxidation reaction are as follows:

at 50 ℃, the CO conversion rate is 0%; at 80 ℃, the CO conversion rate is 28 percent; at 110 ℃, the CO conversion rate is 60 percent; at 130 ℃, the CO conversion rate is 90 percent; at 130 ℃, the CO conversion rate is 100 percent; at 400 ℃, the conversion of CO is 100%.

[ example 11 ]

(1) Namely, according to the molar ratio of lanthanum nitrate: cerium nitrate: cobalt nitrate: platinum nitrate: citric acid: preparing a solution according to the ratio of 0.95:0.05:0.875:0.125:2.4: 0.48; (2) stirring the solution obtained in the step (1) in a water bath kettle at the temperature of 80 ℃ until sol is formed, and obtaining an intermediate product; (3) transferring the product obtained in the step (2) to a constant-temperature drying oven to be dried for 12 hours at 120 ℃ to obtain a dried product; (4) respectively roasting the product obtained in the step (3) at 300 ℃ and 600 ℃ for 2h and 5h to obtain a catalyst precursor La_0.95Ce_0.05Co_0.87Pt_0.13O₃. (5) Placing the catalyst precursor obtained in the step (4) into a reactor, and introducing 12000 ml/(g) into the reactor_cath) Reducing the catalyst precursor, wherein the heating rate is 2 ℃/min; the temperature is 600 ℃; the reduction time was 2 h. The catalyst Pt-Co/La-Ce-O is obtained.

Under the above conditions, the results of the CO oxidation reaction are as follows:

at 50 ℃, the CO conversion rate is 0%; at 80 ℃, the CO conversion rate is 15 percent; at 110 ℃, the CO conversion rate is 30 percent; at 130 ℃, the CO conversion rate is 37%; at 350 ℃, the CO conversion rate is 100 percent; at 400 ℃, the conversion of CO is 100%.

[ example 12 ]

(1) Namely, according to the molar ratio of lanthanum nitrate: cerium nitrate: cobalt nitrate: platinum nitrate: citric acid: preparing a solution according to the ratio of 0.90:0.10:0.875:0.125:2.4: 0.48; (2) stirring the solution obtained in the step (1) in a water bath kettle at the temperature of 80 ℃ until sol is formed, and obtaining an intermediate product; (3) transferring the product obtained in the step (2) to a constant-temperature drying oven to be dried for 12 hours at 120 ℃ to obtain a dried product; (4) respectively roasting the product obtained in the step (3) at 300 ℃ and 600 ℃ for 2h and 5h to obtain a catalyst precursor La_0.90Ce_0.10Co_0.87Pt_0.13O₃(ii) a (5) Placing the catalyst precursor obtained in the step (4) into a reactor, and introducing 12000 ml/(g) into the reactor_cath) Reducing the catalyst precursor, wherein the heating rate is 2 ℃/min; the temperature is 600 ℃; the reduction time was 2 h. The catalyst Pt-Co/La-Ce-O is obtained.

Under the above conditions, the results of the CO oxidation reaction are as follows:

at 50 ℃, the CO conversion rate is 0%; at 80 ℃, the CO conversion rate is 18 percent; at 110 ℃, the CO conversion rate is 33%; at 130 ℃, the CO conversion rate is 41 percent; at 340 ℃, the CO conversion rate is 100 percent; at 400 ℃, the conversion of CO is 100%.

[ example 13 ]

(1) Namely, according to the molar ratio of lanthanum nitrate: cerium nitrate: cobalt nitrate: platinum nitrate: citric acid: preparing a solution according to the ratio of 0.85:0.15:0.875:0.125:2.4: 0.48; (2) stirring the solution obtained in the step (1) in a water bath kettle at the temperature of 80 ℃ until sol is formed, and obtaining an intermediate product; (3) transferring the product obtained in the step (2) to a constant-temperature drying oven to be dried for 12 hours at 120 ℃ to obtain a dried product; (4) namely, the step (3) isThe obtained product is respectively roasted for 2h and 5h at 300 ℃ and 600 ℃ to obtain a catalyst precursor La_0.85Ce_0.15Co_0.87Pt_0.13O₃. (5) Placing the catalyst precursor obtained in the step (4) into a reactor, and introducing 12000 ml/(g) into the reactor_cath) Reducing the catalyst precursor, wherein the heating rate is 2 ℃/min; the temperature is 600 ℃; the reduction time was 2 h. The catalyst Pt-Co/La-Ce-O is obtained.

Under the above conditions, the results of the CO oxidation reaction are as follows:

at 50 ℃, the CO conversion rate is 0%; at 80 ℃, the CO conversion rate is 19 percent; at 110 ℃, the CO conversion rate is 35 percent; at 130 ℃, the CO conversion rate is 45 percent; at 330 ℃, the CO conversion rate is 100 percent; at 400 ℃, the conversion of CO is 100%.

[ example 14 ]

(1) Namely, according to the molar ratio of lanthanum nitrate: cerium nitrate: cobalt nitrate: platinum nitrate: citric acid: preparing a solution according to the ratio of 0.80:0.20:0.875:0.125:2.4: 0.48; (2) stirring the solution obtained in the step (1) in a water bath kettle at the temperature of 80 ℃ until sol is formed, and obtaining an intermediate product; (3) transferring the product obtained in the step (2) to a constant-temperature drying oven to be dried for 12 hours at 120 ℃ to obtain a dried product; (4) respectively roasting the product obtained in the step (3) at 300 ℃ and 600 ℃ for 2h and 5h to obtain a catalyst precursor La_0.80Ce_0.20Co_0.87Pt_0.13O₃. (5) Placing the catalyst precursor obtained in the step (4) into a reactor, and introducing 12000 ml/(g) into the reactor_cath) Reducing the catalyst precursor, wherein the heating rate is 2 ℃/min; the temperature is 600 ℃; the reduction time was 2 h. The catalyst Pt-Co/La-Ce-O is obtained.

Adding a catalyst into a reactor, and heating at 50-400 ℃ under the pressure of 0.1MPaIntroducing 24000 ml/(g) of volume space velocity into the reactor_cath) Wherein the molar ratio of carbon monoxide, oxygen and nitrogen is 1:1: 98.

Under the above conditions, the results of the CO oxidation reaction are as follows:

at 50 ℃, the CO conversion rate is 0%; at 80 ℃, the CO conversion rate is 19 percent; at 110 ℃, the CO conversion rate is 38 percent; at 130 ℃, the CO conversion rate is 47 percent; at 320 ℃, the CO conversion rate is 100 percent; at 400 ℃, the conversion of CO is 100%.

[ example 15 ]

(1) Namely, according to the molar ratio of lanthanum nitrate: cerium nitrate: cobalt nitrate: platinum nitrate: citric acid: preparing a solution according to the ratio of 0.75:0.25:0.875:0.125:2.4: 0.48; (2) stirring the solution obtained in the step (1) in a water bath kettle at the temperature of 80 ℃ until sol is formed, and obtaining an intermediate product; (3) transferring the product obtained in the step (2) to a constant-temperature drying oven to be dried for 12 hours at 120 ℃ to obtain a dried product; (4) respectively roasting the product obtained in the step (3) at 300 ℃ and 600 ℃ for 2h and 5h to obtain a catalyst precursor La_0.75Ce_0.25Co_0.87Pt_0.13O₃(ii) a (5) Placing the catalyst precursor obtained in the step (4) into a reactor, and introducing 12000 ml/(g) into the reactor_cath) Reducing the catalyst precursor, wherein the heating rate is 2 ℃/min; the temperature is 600 ℃; the reduction time was 2 h. The catalyst Pt-Co/La-Ce-O is obtained.

Under the above conditions, the results of the CO oxidation reaction are as follows:

at 50 ℃, the CO conversion rate is 0%; at 80 ℃, the CO conversion rate is 15 percent; at 110 ℃, the CO conversion rate is 33%; at 130 ℃, the CO conversion rate is 39%; at 340 ℃, the CO conversion rate is 100 percent; at 400 ℃, the conversion of CO is 100%.

[ example 16 ]

(1) Namely, according to the molar ratio of lanthanum nitrate: cerium nitrate: cobalt nitrate: platinum nitrate: citric acid: preparing a solution according to the ratio of 0.95:0.05:0.875:0.125:2.4: 0.48; (2) namely, the prepared solution is immersed in SiO in equal volume according to the mass fraction of the perovskite in the catalyst of 10.78 percent₂Standing the carrier for 24 hours, and then placing the sample in a constant-temperature drying oven to be dried for 6 hours at the temperature of 80 ℃ to obtain an intermediate product; (3) heating the product obtained in the step (2) to 120 ℃ and drying for 12h to obtain a dried product; (4) respectively roasting the product obtained in the step (3) at 300 ℃ and 600 ℃ for 2h and 5h to obtain a catalyst precursor La_0.95Ce_0.05Co_0.87Pt_0.13O₃/SiO₂. (5) Placing the catalyst prepared in the step (4) into a reactor, and introducing 12000 ml/(g) into the reactor_cath) Reducing the catalyst precursor, wherein the heating rate is 2 ℃/min; the temperature is 600 ℃; the reduction time is 2h, and Pt-Co/La-Ce-O/SiO is obtained₂A catalyst. As shown in fig. 2, (a) in fig. 2 is an X-ray diffraction (XRD) pattern of the catalyst.

Under the above conditions, the results of the CO oxidation reaction are as follows:

at 50 ℃, the CO conversion rate is 0%; at 80 ℃, the CO conversion rate is 32 percent; at 110 ℃, the CO conversion rate is 62 percent; at 120 ℃, the CO conversion rate is 94%; at 130 ℃, the CO conversion rate is 100 percent; at 400 ℃, the conversion of CO is 100%.

[ example 17 ]

(1) Namely, according to the molar ratio of lanthanum nitrate: cerium nitrate: cobalt nitrate: platinum nitrate: citric acid: preparing a solution according to the ratio of 0.90:0.10:0.875:0.125:2.4: 0.48; (2) namely, the prepared solution is immersed in SiO in equal volume according to the mass fraction of the perovskite in the catalyst of 10.78 percent₂Standing for 24h on the carrier, and then placing the sampleDrying for 6h at 80 ℃ in a constant-temperature drying oven to obtain an intermediate product; (3) heating the product obtained in the step (2) to 120 ℃ and drying for 12h to obtain a dried product; (4) respectively roasting the product obtained in the step (3) at 300 ℃ and 600 ℃ for 2h and 5h to obtain a catalyst precursor La_0.90Ce_0.10Co_0.87Pt_0.13O₃/SiO₂. (5) Placing the catalyst precursor prepared in the step (4) into a reactor, and introducing 12000 ml/(g) into the reactor_cath) Reducing the catalyst precursor, wherein the heating rate is 2 ℃/min; the temperature is 600 ℃; the reduction time is 2h, and Pt-Co/La-Ce-O/SiO is obtained₂A catalyst. As shown in fig. 2, (b) in fig. 2 is an X-ray diffraction (XRD) pattern of the catalyst.

Under the above conditions, the results of the CO oxidation reaction are as follows:

at 50 ℃, the CO conversion rate is 0%; at 80 ℃, the CO conversion rate is 36 percent; at 100 ℃, the CO conversion rate is 50 percent; at 110 ℃, the CO conversion rate is 64 percent; at 120 ℃, the CO conversion rate is 100 percent; at 400 ℃, the conversion of CO is 100%.

[ example 18 ]

(1) Namely, according to the molar ratio of lanthanum nitrate: cerium nitrate: cobalt nitrate: platinum nitrate: citric acid: preparing a solution according to the ratio of 0.85:0.15:0.875:0.125:2.4: 0.48; (2) namely, the prepared solution is immersed in SiO in equal volume according to the mass fraction of the perovskite in the catalyst of 10.78 percent₂Standing the carrier for 24 hours, and then placing the sample in a constant-temperature drying oven to be dried for 6 hours at the temperature of 80 ℃ to obtain an intermediate product; (3) heating the product obtained in the step (2) to 120 ℃ and drying for 12h to obtain a dried product; (4) respectively roasting the product obtained in the step (3) at 300 ℃ and 600 ℃ for 2h and 5h to obtain a catalyst precursor La_0.85Ce_0.15Co_0.87Pt_0.13O₃/SiO₂. (5) Placing the catalyst precursor prepared in the step (4) into a reactor, and introducing 12000 ml/(g) into the reactor_cath) Reducing the catalyst precursor, wherein the heating rate is 2 ℃/min; the temperature is 600 ℃; the reduction time is 2h, and Pt-Co/La-Ce-O/SiO is obtained₂A catalyst. As shown in fig. 2, (c) in fig. 2 is an X-ray diffraction (XRD) pattern of the catalyst.

Under the above conditions, the results of the CO oxidation reaction are as follows:

at 50 ℃, the CO conversion rate is 0%; at 80 ℃, the CO conversion rate is 38 percent; at 100 ℃, the CO conversion rate is 53 percent; at 110 ℃, the CO conversion rate is 68 percent; at 120 ℃, the CO conversion rate is 100 percent; at 400 ℃, the conversion of CO is 100%.

[ example 19 ]

(1) Namely lanthanum nitrate: cerium nitrate: cobalt nitrate: platinum nitrate: citric acid: preparing a solution according to the ratio of 0.80:0.20:0.875:0.125:2.4: 0.48; (2) namely, the prepared solution is immersed in SiO in equal volume according to the mass fraction of the perovskite in the catalyst of 10.78 percent₂Standing the carrier for 24 hours, and then placing the sample in a constant-temperature drying oven to be dried for 6 hours at the temperature of 80 ℃ to obtain an intermediate product; (3) heating the product obtained in the step (2) to 120 ℃ and drying for 12h to obtain a dried product; (4) respectively roasting the product obtained in the step (3) at 300 ℃ and 600 ℃ for 2h and 5h to obtain a catalyst precursor La_0.80Ce_0.20Co_0.87Pt_0.13O₃/SiO₂. (5) Placing the catalyst precursor prepared in the step (4) into a reactor, and introducing 12000 ml/(g) into the reactor_cath) Reducing the catalyst precursor, wherein the heating rate is 2 ℃/min; the temperature is 600 ℃; the reduction time is 2h, and Pt-Co/La-Ce-O/SiO is obtained₂A catalyst. As shown in FIGS. 2,3 and 4, in FIG. 2 (d) isAn X-ray diffraction (XRD) pattern of the catalyst; FIG. 3 is a graph of the results of a stability test of the catalyst; FIG. 4 is a graph of the results of line scans of La, Ce, Co, Pt for the catalyst.

Under the above conditions, the results of the CO oxidation reaction are as follows:

at 50 ℃, the CO conversion rate is 0%; at 80 ℃, the CO conversion rate is 40 percent; at 100 ℃, the CO conversion rate is 56 percent; at 110 ℃, the CO conversion rate is 72 percent; at 120 ℃, the CO conversion rate is 100 percent; at 400 ℃, the conversion of CO is 100%.

[ example 20 ]

(1) Namely, according to the molar ratio of lanthanum nitrate: cerium nitrate: cobalt nitrate: platinum nitrate: citric acid: preparing a solution according to the ratio of 0.75:0.25:0.875:0.125:2.4: 0.48; (2) namely, the prepared solution is immersed in SiO in equal volume according to the mass fraction of the perovskite in the catalyst of 10.78 percent₂Standing the carrier for 24 hours, and then placing the sample in a constant-temperature drying oven to be dried for 6 hours at the temperature of 80 ℃ to obtain an intermediate product; (3) heating the product obtained in the step (2) to 120 ℃ and drying for 12h to obtain a dried product; (4) respectively roasting the product obtained in the step (3) at 300 ℃ and 600 ℃ for 2h and 5h to obtain a catalyst precursor La_0.75Ce_0.25Co_0.87Pt_0.13O₃/SiO₂. (5) Placing the catalyst precursor prepared in the step (4) into a reactor, and introducing 12000 ml/(g) into the reactor_cath) Reducing the catalyst precursor, wherein the heating rate is 2 ℃/min; the temperature is 600 ℃; the reduction time is 2h, and Pt-Co/La-Ce-O/SiO is obtained₂A catalyst. As shown in fig. 2, (e) in fig. 2 is an X-ray diffraction (XRD) pattern of the catalyst.

Under the above conditions, the results of the CO oxidation reaction are as follows:

at 50 ℃, the CO conversion rate is 0%; at 80 ℃, the CO conversion rate is 48 percent; at 100 ℃, the CO conversion rate is 64 percent; at 110 ℃, the CO conversion rate is 82 percent; at 120 ℃, the CO conversion rate is 100 percent; at 400 ℃, the conversion of CO is 100%.

[ example 21 ]

1, 2B, 3,4, namely, lanthanum nitrate in a molar ratio: cerium nitrate: cobalt nitrate: platinum nitrate: citric acid: preparing a solution according to the ratio of 0.80:0.20:0.875:0.125:2.4: 0.48; (2) namely, the prepared solution is immersed in SiO in equal volume according to the mass fraction of 5% of perovskite in the catalyst₂Standing the carrier for 12h, and then placing the sample in a constant-temperature drying oven to be dried for 3h at the temperature of 60 ℃ to obtain an intermediate product; (3) heating the product obtained in the step (2) to 100 ℃ and drying for 6h to obtain a dried product; (4) respectively roasting the product obtained in the step (3) at 250 ℃ and 550 ℃ for 1h and 4h to obtain a catalyst precursor and obtain the catalyst La_0.80Ce_0.20Co_0.87Pt_0.13O₃/SiO₂. (5) Placing the catalyst prepared in the step (4) into a reactor, and introducing 10000 ml/(g) into the reactor_cath) Reducing the catalyst precursor, wherein the heating rate is 5 ℃/min; the temperature is 550 ℃; the reduction time is 1h, and Pt-Co/La-Ce-O/SiO is obtained₂A catalyst.

Adding a catalyst into a reactor, and introducing 15000 ml/(g) into the reactor at a volume space velocity under the conditions that the temperature is 50-400 ℃ and the pressure is 0.1MPa_cath) Wherein the molar ratio of carbon monoxide, oxygen and nitrogen is 0.1:0.1: 99.8.

Under the above conditions, the results of the CO oxidation reaction are as follows:

at 50 ℃, the CO conversion rate is 0%; at 80 ℃, the CO conversion rate is 20 percent; at 100 ℃, the CO conversion rate is 28 percent; at 110 ℃, the CO conversion rate is 50 percent; at 180 ℃, the CO conversion rate is 100 percent; at 400 ℃, the conversion of CO is 100%.

[ example 22 ]

1, 2B, 3,4, namely, lanthanum nitrate in a molar ratio: cerium nitrate: cobalt nitrate: platinum nitrate: citric acid: preparing a solution according to the ratio of 0.80:0.20:0.875:0.125:2.4: 0.48; (2) namely, the prepared solution is immersed in SiO in equal volume according to the mass fraction of the perovskite in the catalyst being 20 percent₂Standing the carrier for 48 hours, and then placing the sample in a constant-temperature drying oven to be dried for 8 hours at the temperature of 90 ℃ to obtain an intermediate product; (3) heating the product obtained in the step (2) to 150 ℃ and drying for 24h to obtain a dried product; (4) respectively roasting the product obtained in the step (3) at 350 ℃ and 750 ℃ for 3h and 6h to obtain a catalyst precursor and obtain the catalyst La_0.80Ce_0.20Co_0.87Pt_0.13O₃/SiO₂. (5) Putting the catalyst prepared in the step (4) into a reactor, and introducing 15000 ml/(g) into the reactor_cath) Reducing the catalyst precursor, wherein the heating rate is 10 ℃/min; the temperature is 650 ℃; the reduction time is 3h, and Pt-Co/La-Ce-O/SiO is obtained₂A catalyst.

Adding a catalyst into a reactor, and introducing 36000 ml/(g) into the reactor at a volume space velocity of 50-400 ℃ and a pressure of 0.1MPa_cath) Wherein the molar ratio of carbon monoxide, oxygen and nitrogen is 2:2: 96.

Under the above conditions, the results of the CO oxidation reaction are as follows:

at 50 ℃, the CO conversion rate is 0%; at 80 ℃, the CO conversion rate is 33 percent; at 100 ℃, the CO conversion rate is 43 percent; at 110 ℃, the CO conversion rate is 69%; at 150 ℃, the CO conversion rate is 100 percent; at 400 ℃, the conversion of CO is 100%.

[ example 23 ]

Under the above conditions, the results of the CO oxidation reaction are as follows:

at 50 ℃, the CO conversion rate is 0%; at 80 ℃, the CO conversion rate is 41 percent; at 100 ℃, the CO conversion rate is 54 percent; at 110 ℃, the CO conversion rate is 70 percent; at 120 ℃, the CO conversion rate is 100 percent; at 400 ℃, the conversion of CO is 100%.

[ example 24 ]

(1) Namely, according to the molar ratio of lanthanum nitrate: cerium nitrate: cobalt nitrate: platinum nitrate: citric acid: preparing a solution according to the ratio of 0.75:0.25:0.875:0.125:2.4: 0.48; (2) stirring the solution obtained in the step (1) in a water bath kettle at 60 ℃ until sol is formed, and obtaining an intermediate product; (3) transferring the product obtained in the step (2) to a constant-temperature drying oven to be dried for 6 hours at 100 ℃ to obtain a dried product; (4) respectively roasting the product obtained in the step (3) at 250 ℃ and 550 ℃ for 1h and 4h to obtain a catalyst precursor La_0.75Ce_0.25Co_0.87Pt_0.13O₃. (5) Placing the catalyst precursor obtained in the step (4) into a reactor, and introducing 10000 ml/(g) into the reactor_cath) Hydrogen ofGas, reducing the catalyst precursor, wherein the heating rate is 5 ℃/min; the temperature is 550 ℃; the reduction time was 1 h. The catalyst Pt-Co/La-Ce-O is obtained.

Under the above conditions, the results of the CO oxidation reaction are as follows:

at 50 ℃, the CO conversion rate is 0%; at 80 ℃, the CO conversion rate is 18 percent; at 110 ℃, the CO conversion rate is 30 percent; at 130 ℃, the CO conversion rate is 43 percent; at 340 ℃, the CO conversion rate is 100 percent; at 400 ℃, the conversion of CO is 100%.

[ example 25 ]

(1) Namely, according to the molar ratio of lanthanum nitrate: cerium nitrate: cobalt nitrate: platinum nitrate: citric acid: preparing a solution according to the ratio of 0.75:0.25:0.875:0.125:2.4: 0.48; (2) stirring the solution obtained in the step (1) in a water bath kettle at 90 ℃ until sol is formed, and obtaining an intermediate product; (3) transferring the product obtained in the step (2) to a constant-temperature drying oven to be dried for 24 hours at the temperature of 150 ℃ to obtain a dried product; (4) respectively roasting the product obtained in the step (3) at 350 ℃ and 750 ℃ for 3h and 6h to obtain a catalyst precursor La_0.75Ce_0.25Co_0.87Pt_0.13O₃. (5) Putting the catalyst precursor obtained in the step (4) into a reactor, and introducing 15000 ml/(g) into the reactor_cath) Reducing the catalyst precursor, wherein the heating rate is 10 ℃/min; the temperature is 550 ℃; the reduction time was 3 h. The catalyst Pt-Co/La-Ce-O is obtained.

Under the above conditions, the results of the CO oxidation reaction are as follows:

at 50 ℃, the CO conversion rate is 0%; at 80 ℃, the CO conversion rate is 10 percent; at 110 ℃, the CO conversion rate is 17%; at 130 ℃, the CO conversion rate is 30 percent; at 370 ℃, the conversion rate of CO is 100%; at 400 ℃, the conversion of CO is 100%.

[ example 26 ]

Under the above conditions, the results of the CO oxidation reaction are as follows:

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Oxide-modified Pt-Co bimetallic catalyst, preparation method and application thereof to CO oxidation

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