A cerium-aluminum-based monolithic catalyst, a preparation method and application thereof

Abstract

The application belongs to the technical field of catalysts, and particularly relates to a cerium-aluminum-based monolithic catalyst and a preparation method and application thereof. The cerium-aluminum-based monolithic catalyst is prepared from raw materials including bauxite 1-10 parts, cerium dioxide 1-10 parts, starch 0.1-5 parts, a binder 0.01-1 parts, and water 0.1-10 parts. The preparation method comprises the following steps: after the bauxite and the cerium dioxide are fully mixed, a mixed solution of the binder and the water is added for bonding, the bonded blank is aged, then further mixed, and then subjected to an extrusion operation to obtain a monolithic catalyst green body, then dried, and finally calcined to obtain the cerium-aluminum-based monolithic catalyst. Through the interaction between the bauxite and the cerium dioxide, the support can serve as a framework of the catalyst and provide good activity, and in combination with a suitable raw material ratio and a calcination temperature, the application has excellent catalytic effect on industrial volatile organic methyl ethyl ketone.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of catalysts, and particularly relates to a cerium-aluminum-based monolithic catalyst and a preparation method and application thereof. BACKGROUND

[0002] With the rapid development of China's economy and society, especially the continuous expansion of the scale of petrochemical, textile printing and dyeing, packaging printing, coating, pharmaceutical and other industries, the regional atmospheric complex pollution problem caused by industrial volatile organic emissions is becoming increasingly serious. Methyl ethyl ketone, as an important industrial solvent, is widely used and easily released in many production processes, which will pollute the atmosphere if not treated. Developing typical industrial methyl ethyl ketone pollution control mechanism and green low-temperature control new technology research and application is an important means for China to carry out regional complex pollution prevention and control and improve air quality, and has important practical significance.

[0003] Regenerative catalytic oxidation technology (RCO) is one of the current industrial efficient control technologies of volatile organic compounds, which has the advantages of high waste gas purification efficiency, strong adaptability, low energy consumption, no secondary pollution, etc., and is suitable for organic waste gas purification in pharmaceutical manufacturing, plastics, printing, organic chemical industry, automobile manufacturing, electronic manufacturing and other industries. Monolithic catalyst is the core component of RCO device. The catalyst is composed of active substances and support. The active substances mainly include noble metals, transition metals and rare earth metals, etc., among which the commercial catalyst is mostly noble metal, and the price is very high. The support mainly plays the role of dispersing active substances and ensuring smooth airflow, mainly including ceramic, carbon material, metal, etc. Among them, ceramic-based (mainly containing silicon and aluminum elements) support is widely used due to its good thermal stability, good chemical stability, acid and alkali corrosion resistance, high mechanical strength and long service life, but ceramic material often only serves as the support of the catalyst without significantly playing its own activity. Chinese patent CN102441379A discloses a catalytic combustion catalyst and a preparation method. The catalytic combustion catalyst takes honeycomb ceramic as the carrier, and the surface of the carrier has SiO2 coating and CeO2 coating in sequence. The catalytic combustion catalyst has high coating firmness and high temperature activity stability in the process of treating organic waste gas, and achieves good treatment effect on organic waste gas, but the catalyst does not research the catalytic effect of methyl ethyl ketone, and the content of noble metal is high. At the same time, in order to achieve high activity, the reaction temperature is relatively high.

[0004] At present, the existing monolithic catalysts are mostly used for treating total exhaust gas containing volatile organic compounds, and the research on the catalytic effect of methyl ethyl ketone is less and the process is complex. Chinese patent CN106955701B discloses a kind of high dispersion Pt catalyst supported by aluminum-containing silicon dioxide, which uses synthetic potassium modified rod-shaped aluminum-containing silicon dioxide as carrier to prepare a new type of catalyst with low Pt content and highly dispersed active phase. The catalyst is prepared by double surfactant method, hydrothermal synthesis method, post modification aluminumization method, ion exchange method, ethylene glycol reduction method and colloidal impregnation method, and shows good catalytic effect on methyl ethyl ketone. However, the preparation process of the new catalyst is too complex, which is not conducive to industrial production, and the catalyst is not monolithic, which limits its practical application. SUMMARY

[0005] The present application provides a cerium-aluminum-based monolithic catalyst, a preparation method and application thereof to solve the problems of the existing catalysts for treating methyl ethyl ketone.

[0006] The first object of the present application is achieved by the following technical solution:

[0007] A cerium-aluminum-based monolithic catalyst is prepared from raw materials including bauxite 1-10 parts, cerium dioxide 1-10 parts, starch 0.1-5 parts, binder 0.01-1 parts and water 0.1-10 parts.

[0008] Preferably, the cerium-aluminum-based monolithic catalyst is prepared from raw materials including bauxite 5-9 parts, cerium dioxide 1-5 parts, starch 0.5-1 parts, binder 0.1-0.5 parts and water 1-5 parts.

[0009] Preferably, the mass ratio of bauxite to cerium dioxide is (10-1):1.

[0010] Further preferably, the mass ratio of bauxite to cerium dioxide is (6-1):1. Reasonably controlling the ratio of bauxite to cerium dioxide can further improve the catalytic effect of the cerium-aluminum-based monolithic catalyst on methyl ethyl ketone. When the mass ratio of bauxite to cerium dioxide in the cerium-aluminum-based monolithic catalyst is too high or too low, the conversion effect of the cerium-aluminum-based monolithic catalyst on methyl ethyl ketone decreases.

[0011] Still further preferably, the mass ratio of bauxite to cerium dioxide is (1.5-2.0):1.

[0012] Preferably, the bauxite is composed of SiO220-50 parts, Al2O350-80 parts, Fe2O31-10 parts, TiO21-10 parts, K2O 0.1-10 parts and CaO 0.1-10 parts.

[0013] Further preferably, the bauxite consists of components comprising the following weight parts: SiO2 30-40 parts, Al2O3 60-70 parts, Fe2O3 3-8 parts, TiO2 3-8 parts, K2O 1-5 parts, CaO 1-5 parts.

[0014] As preferred, the average particle size of the bauxite is 1-500 μm; further preferably, the average particle size of the bauxite is 1-100 μm.

[0015] As preferred, the purity of the cerium dioxide is 90-100%.

[0016] Further preferably, the purity of the cerium dioxide is > 99%; still further preferably, the purity of the cerium dioxide is > 99.9%.

[0017] As preferred, the average particle size of the cerium dioxide is 0.1-50 μm; further preferably, the average particle size of the cerium dioxide is 0.1-10 μm.

[0018] As preferred, the binder comprises one or more of polyvinyl alcohol, polyammonium acrylate, polyurethane, polyamide.

[0019] Further preferably, the binder is polyvinyl alcohol.

[0020] Preferably, the molecular weight of the polyvinyl alcohol is 1000-100000.

[0021] Further preferably, the molecular weight of the polyvinyl alcohol is 5000-50000.

[0022] As preferred, the cerium-aluminum based monolithic catalyst is cylindrical.

[0023] As preferred, the length of the cerium-aluminum based monolithic catalyst is 0.1-100 cm, further optimized to 1-10 cm.

[0024] As preferred, the diameter of the cerium-aluminum based monolithic catalyst is 0.1-100 cm, further optimized to 1-10 cm.

[0025] As preferred, the cerium-aluminum based monolithic catalyst has 5-50 channels, the channels being axial channels.

[0026] As preferred, the channels are cylindrical, each channel having a diameter of 0.1-1 cm.

[0027] The cerium-aluminum-based monolithic catalyst of the present application has macroscopic channels in the axial direction, and the through channels in the axial direction enhance the heat dissipation capacity of the monolithic catalyst in all directions, so that the large amount of heat generated during the reaction can be dissipated in time, and local sintering in the catalyst is avoided, thereby further improving the conversion rate of raw materials.

[0028] Preferably, the specific surface area of the cerium-aluminum-based monolithic catalyst is 40-100 m 2 / g.

[0029] Preferably, the T 50 of the cerium-aluminum-based monolithic catalyst for methyl ethyl ketone is 150-200℃, the T 90 is 150-250℃, wherein T 50 and T 90 represent the temperatures at which the methyl ethyl ketone conversion rate is 50% and 90%, respectively, and the methyl ethyl ketone conversion rate is calculated as follows:

[0030]

[0031] wherein [methyl ethyl ketone] in represents the inlet concentration of methyl ethyl ketone in the reactor; and [methyl ethyl ketone] out represents the outlet concentration of methyl ethyl ketone in the reactor.

[0032] The second object of the present application is achieved by the following technical solution:

[0033] A preparation method of a cerium-aluminum-based monolithic catalyst, comprising the following steps: fully mixing bauxite, cerium dioxide and starch, adding a mixture of a binder and water for bonding, aging the bonded blank, further mixing, performing extrusion operation to obtain a monolithic catalyst green body, then drying, and finally calcining to obtain the cerium-aluminum-based monolithic catalyst.

[0034] Preferably, the bauxite, cerium dioxide and starch are fully mixed for 1-10 hours in the preparation method.

[0035] Preferably, the aged bonded blank is further mixed for 1-10 hours in the preparation method.

[0036] Preferably, the aged blank is further mixed for 1-10 hours in the preparation method.

[0037] Preferably, the extrusion operation is performed in an extruder, and the extrusion pressure of the extruder is 1-20 MPa in the preparation method.

[0038] Preferably, the green body of the monolithic catalyst is dried at a temperature of 20-30℃ and a humidity of 75-85% for 1-10 hours in the preparation method, and then transferred to a constant temperature air drying oven at 50-100℃ for 1-20 hours.

[0039] Preferably, the calcination temperature is 400-700℃ and the calcination time is 1-10 hours in the preparation method.

[0040] Further preferably, the calcination temperature is 450-650℃, and most preferably, the calcination temperature is 550℃.

[0041] Preferably, the temperature is increased to the calcination temperature at a rate of 1-10℃ / min.

[0042] A third object of the present application is achieved by the following technical solution:

[0043] Application of a cerium-aluminum-based monolithic catalyst in catalytic oxidation of methyl ethyl ketone.

[0044] The cerium-aluminum-based monolithic catalyst catalytically converts methyl ethyl ketone into CO2 and H2O.

[0045] Preferably, the cerium-aluminum-based monolithic catalyst has a T 50 of 150-200℃, and a T 90 of 150-250℃.

[0046] Compared with the prior art, the present application has the following beneficial effects:

[0047] 1. The bauxite is used as the main raw material of the monolithic catalyst in the present application, which can be used as the support skeleton of the monolithic catalyst and play the role of the carrier of the monolithic catalyst. The hydroxyl groups on the surface of the bauxite help to adsorb methyl ethyl ketone. In addition, other metal oxides in the bauxite can be used as the catalytic active sites of the catalyst to further improve the catalytic oxidation effect of the monolithic catalyst.

[0048] 2. The bauxite and cerium dioxide interact with each other in the present application, so that the support can not only be used as the skeleton of the catalyst but also provide good activity. The ratio of the bauxite to the cerium dioxide is reasonably controlled, which further improves the catalytic effect of the cerium-aluminum-based monolithic catalyst on methyl ethyl ketone.

[0049] 3. The bauxite and cerium dioxide are used as the raw materials in the present application, and a suitable calcination temperature is used to prepare the cerium-aluminum-based monolithic catalyst. The interaction between aluminum and cerium is fully utilized, and the catalyst has excellent catalytic effect on industrial volatile organic compounds methyl ethyl ketone. BRIEF DESCRIPTION OF DRAWINGS

[0050] Figure 1Particle size distribution of ceria and bauxite used in the examples and comparative examples of the present application;

[0051] Figure 2 Scanning electron micrograph of ceria and bauxite used in the examples and comparative examples of the present application;

[0052] Figure 3 Physical photograph of the monolithic catalysts CA1-550, CA2-550, CA3-550, CA4-550 and CS-550 of Examples 2, 5, 8, 11 and Comparative Example 2;

[0053] Figure 4 Physical photograph and specific dimensions of the cerium-aluminum based monolithic catalyst CA3-550 of Example 8;

[0054] Figure 5 XRD pattern of the monolithic catalysts of Examples 1 to 12 and Comparative Examples 1 to 3;

[0055] Figure 6 Conversion of methyl ethyl ketone of the monolithic catalysts of Examples 1 to 12 and Comparative Examples 1 to 3;

[0056] Figure 7 Conversion effect of the monolithic catalysts CA1-550, CA2-550, CA3-550, CA4-550, CS-550, bauxite catalyst and ceria catalyst of Examples 2, 5, 8, 11 and Comparative Examples 2, 4, 5, wherein Figure 7 (a) is the conversion of methyl ethyl ketone of the above examples and comparative examples, Figure 7 (b) is the T 90 and T 50 distribution of methyl ethyl ketone of the above examples and comparative examples. DETAILED DESCRIPTION

[0057] The technical solutions of the present application will be further described and illustrated with specific examples and the accompanying drawings. It should be understood that the specific examples described herein are only used to illustrate the present application and not to limit the scope of the present application. Moreover, the drawings used herein are only used to better illustrate the disclosed content of the present application and do not limit the scope of protection. Furthermore, it should be understood that after reading the content of the present application, those skilled in the art can make various modifications or changes to the present application, and these equivalent forms also fall within the scope of the appended claims of the present application.

[0058] The bauxite used in the following examples is composed of the following raw materials in parts by weight: Fe2O3 4.6 parts, SiO2 30.8 parts, Al2O3 63.7 parts, CaO 1.2 parts, K2O 1.3 parts, TiO2 4.6 parts;

[0059] The purity of the cerium dioxide is 99.9%.

[0060] Figure 1 The particle size distribution diagram of the cerium dioxide and bauxite used in the examples and comparative examples of the present application can be seen that the particle size of the bauxite is mainly concentrated in 25.5 μm, and the particle size of the cerium dioxide is mainly concentrated in 5.7 μm.

[0061] Figure 2 The scanning electron microscope diagram of the cerium dioxide and bauxite used in the examples and comparative examples of the present application.

[0062] Example 1

[0063] The cerium-aluminum based monolithic catalyst of the present example is processed from the following raw materials by weight: bauxite 8.75 kg, cerium dioxide 1.25 kg, starch 0.5 kg, polyvinyl alcohol (molecular weight 20000) 0.2 kg, water 3 kg.

[0064] The preparation method of the above cerium-aluminum based monolithic catalyst comprises the following steps: after 8.75 kg of bauxite, 1.25 kg of cerium dioxide and 0.5 kg of starch are mixed in a mixer for 5 h, a mixture of 0.2 kg of polyvinyl alcohol and 3 kg of water is added for bonding, the kneaded green material is aged for 3 h, then transferred to a vacuum pug mill for further mixing for 3 h, and then added to a vacuum extruder, the extrusion pressure is 8 MPa, the extrusion operation is carried out, the monolithic catalyst green body is obtained, then dried at 28℃ and humidity 80% for 6 h, then transferred to a constant temperature air drying oven at 70℃ for drying for 12 h, finally heated to 450℃ at a rate of 5℃ / min at room temperature, calcined for 3 h, and the cerium-aluminum based monolithic catalyst CA1-450 is obtained.

[0065] The specific surface area of the cerium-aluminum based monolithic catalyst CA1-450 of the present example is 61.4 m 2 / g.

[0066] Example 2

[0067] The raw materials of the cerium-aluminum based monolithic catalyst of the present example are the same as those of example 1, the difference is only that the calcination temperature in the preparation method of the cerium-aluminum based monolithic catalyst is 550℃, the cerium-aluminum based monolithic catalyst CA1-550 is obtained, and the remaining steps are the same as those of example 1.

[0068] The specific surface area of the cerium-aluminum based monolithic catalyst CA1-550 of the present example is 55.8 m 2 / g.

[0069] Example 3

[0070] The raw materials of the cerium-aluminum based monolithic catalyst of this example are the same as those of Example 1, except that the calcination temperature in the preparation method of the cerium-aluminum based monolithic catalyst is 650°C, to obtain a cerium-aluminum based monolithic catalyst CA1-650, and the remaining steps are the same as those of Example 1.

[0071] The specific surface area of the cerium-aluminum based monolithic catalyst CA1-650 of this example is 48.7 m 2 / g.

[0072] Example 4

[0073] The cerium-aluminum based monolithic catalyst of this example is processed from the following raw materials by weight: bauxite 7.5 kg, cerium dioxide 2.5 kg, starch 0.5 kg, polyvinyl alcohol (molecular weight 20000) 0.2 kg, and water 3 kg.

[0074] The preparation method of the above cerium-aluminum based monolithic catalyst is the same as that of Example 1, including the following steps: after 7.5 kg of bauxite, 2.5 kg of cerium dioxide, and 0.5 kg of starch are thoroughly mixed in a mixer for 5 h, a mixture of 0.2 kg of polyvinyl alcohol and 3 kg of water is added for bonding, the kneaded green material is aged for 3 h, then transferred to a vacuum pug mill for further mixing for 3 h, and then added to a vacuum extruder for extrusion operation at an extrusion pressure of 8 MPa, to obtain a monolithic catalyst green body, which is then dried at 28°C and 80% humidity for 6 h, then transferred to a constant temperature air drying oven at 70°C for drying for 12 h, and finally heated to 450°C at a rate of 5°C / min from room temperature, and calcined for 3 h, to obtain a cerium-aluminum based monolithic catalyst CA2-450.

[0075] The specific surface area of the cerium-aluminum based monolithic catalyst CA2-450 of this example is 69.1 m 2 / g.

[0076] Example 5

[0077] The raw materials of the cerium-aluminum based monolithic catalyst of this example are the same as those of Example 4, except that the calcination temperature in the preparation method of the cerium-aluminum based monolithic catalyst is 550°C, to obtain a cerium-aluminum based monolithic catalyst CA2-550, and the remaining steps are the same as those of Example 4.

[0078] The specific surface area of the cerium-aluminum based monolithic catalyst CA2-550 of this example is 63.5 m 2 / g.

[0079] Example 6

[0080] The raw materials of the cerium-aluminum based monolithic catalyst of this example are the same as those of Example 4, except that the calcination temperature in the preparation method of the cerium-aluminum based monolithic catalyst is 650°C, to obtain a cerium-aluminum based monolithic catalyst CA2-650, and the remaining steps are the same as those of Example 4.

[0081] The specific surface area of the cerium-aluminum-based monolithic catalyst CA2-650 of this example was 59.3 m 2 / g.

[0082] Example 7

[0083] The cerium-aluminum-based monolithic catalyst of this example was processed from the following raw materials by weight: bauxite 6.5 kg, cerium dioxide 3.5 kg, starch 0.5 kg, polyvinyl alcohol (molecular weight 20,000) 0.2 kg, and water 3 kg.

[0084] The cerium-aluminum-based monolithic catalyst of this example was processed from the following raw materials by weight: bauxite 6.5 kg, cerium dioxide 3.5 kg, starch 0.5 kg, polyvinyl alcohol (molecular weight 20,000) 0.2 kg, and water 3 kg.

[0085] The specific surface area of the cerium-aluminum-based monolithic catalyst CA3-450 of this example was 80.6 m 2 / g.

[0086] Example 8

[0087] The raw materials of the cerium-aluminum-based monolithic catalyst of this example were the same as in Example 7, except that the calcination temperature in the preparation method of the cerium-aluminum-based monolithic catalyst was 550°C, and the cerium-aluminum-based monolithic catalyst CA3-550 was obtained, with the remaining steps being the same as in Example 7.

[0088] The specific surface area of the cerium-aluminum-based monolithic catalyst CA3-550 of this example was 72.3 m 2 / g.

[0089] Example 9

[0090] The raw materials of the cerium-aluminum-based monolithic catalyst of this example were the same as in Example 7, except that the calcination temperature in the preparation method of the cerium-aluminum-based monolithic catalyst was 650°C, and the cerium-aluminum-based monolithic catalyst CA3-650 was obtained, with the remaining steps being the same as in Example 7.

[0091] The specific surface area of the cerium-aluminum-based monolithic catalyst CA3-650 of this example was 68.4 m 2 / g.

[0092] Example 10

[0093] The bauxite 5.0 kg, cerium dioxide 5.0 kg, starch 0.5 kg, polyvinyl alcohol (molecular weight 20000) 0.2 kg, and water 3 kg were mixed in a mixer for 5 h, and then a mixture of 0.2 kg of polyvinyl alcohol and 3 kg of water was added for binding. The kneaded material was aged for 3 h, and then transferred to a vacuum pug mill for further mixing for 3 h. The material was then added to a vacuum extruder, and extruded at an extrusion pressure of 8 MPa to obtain a green body of the monolithic catalyst. The green body was then dried at 28 °C and 80% humidity for 6 h, and then transferred to a 70 °C constant temperature air drying oven for drying for 12 h. Finally, the material was heated at a rate of 5 °C / min to 450 °C, and calcined for 3 h to obtain the cerium-aluminum-based monolithic catalyst CA4-450.

[0094] The cerium-aluminum-based monolithic catalyst was prepared according to the method of Example 1, including the following steps: the bauxite 5.0 kg, cerium dioxide 5.0 kg, starch 0.5 kg were mixed in a mixer for 5 h, and then a mixture of 0.2 kg of polyvinyl alcohol and 3 kg of water was added for binding. The kneaded material was aged for 3 h, and then transferred to a vacuum pug mill for further mixing for 3 h. The material was then added to a vacuum extruder, and extruded at an extrusion pressure of 8 MPa to obtain a green body of the monolithic catalyst. The green body was then dried at 28 °C and 80% humidity for 6 h, and then transferred to a 70 °C constant temperature air drying oven for drying for 12 h. Finally, the material was heated at a rate of 5 °C / min to 450 °C, and calcined for 3 h to obtain the cerium-aluminum-based monolithic catalyst CA4-450.

[0095] The specific surface area of the cerium-aluminum-based monolithic catalyst CA4-450 of this example was 94.7 m 2 / g.

[0096] Example 11

[0097] The raw materials of the cerium-aluminum-based monolithic catalyst of this example were the same as those of Example 10, except that the calcination temperature in the preparation method of the cerium-aluminum-based monolithic catalyst was 550 °C, and the cerium-aluminum-based monolithic catalyst CA4-550 was obtained. The other steps were the same as those of Example 10.

[0098] The specific surface area of the cerium-aluminum-based monolithic catalyst CA4-550 of this example was 89.6 m 2 / g.

[0099] Example 12

[0100] The raw materials of the cerium-aluminum-based monolithic catalyst of this example were the same as those of Example 10, except that the calcination temperature in the preparation method of the cerium-aluminum-based monolithic catalyst was 650 °C, and the cerium-aluminum-based monolithic catalyst CA4-650 was obtained. The other steps were the same as those of Example 10.

[0101] The specific surface area of the cerium-aluminum-based monolithic catalyst CA4-650 of this example was 81.3 m 2 / g.

[0102] Comparative Example 1

[0103] The monolithic catalyst of the present comparative example was prepared from the following raw materials in weight parts: ceria 3.5 kg, starch 0.5 kg, SiO2 4.4 kg, Al2O3 2.1 kg, polyvinyl alcohol (molecular weight 20000) 0.2 kg, water 3 kg.

[0104] The preparation method of the monolithic catalyst included the following steps: 3.5 kg of ceria, 0.5 kg of starch, 4.4 kg of SiO2, and 2.1 kg of Al2O3 were thoroughly mixed in a mixer for 5 h, then a mixture of 0.2 kg of polyvinyl alcohol and 3 kg of water was added for bonding, the kneaded green material was aged for 3 h, then transferred to a vacuum pug mill for further mixing for 3 h, and then added to a vacuum extruder for extrusion at an extrusion pressure of 8 MPa to obtain a monolithic catalyst green body, which was then dried at 28°C and 80% humidity for 6 h, then transferred to a 70°C constant-temperature air drying oven for drying for 12 h, and finally heated at a rate of 5°C / min to 450°C at room temperature and calcined for 3 h to obtain the monolithic catalyst CS-450.

[0105] Comparative Example 2

[0106] The raw materials of the monolithic catalyst of the present comparative example were the same as those of Comparative Example 1, except that the calcination temperature in the preparation method of the monolithic catalyst was 550°C to obtain the monolithic catalyst CS-550, and the other steps were the same as those of Comparative Example 1.

[0107] Comparative Example 3

[0108] The raw materials of the monolithic catalyst of the present comparative example were the same as those of Comparative Example 1, except that the calcination temperature in the preparation method of the monolithic catalyst was 650°C to obtain the monolithic catalyst CS-650, and the other steps were the same as those of Comparative Example 1.

[0109] Comparative Example 4

[0110] The bauxite catalyst of the present comparative example was prepared from the following raw materials in weight parts: bauxite 10 kg, starch 0.5 kg, polyvinyl alcohol (molecular weight 20000) 0.2 kg, water 3 kg.

[0111] The preparation method of the bauxite catalyst comprises the following steps: 10 kg of bauxite, 0.5 kg of starch are fully mixed in a mixer for 5 h, then a mixture of 0.2 kg of polyvinyl alcohol and 3 kg of water is added for bonding, the kneaded green material is aged for 3 h, then transferred to a vacuum pug mill for further mixing for 3 h, and then added to a vacuum extruder, the extrusion pressure is 8 MPa, the extrusion operation is performed, the monolithic catalyst green body is obtained, then dried at 28℃ and 80% humidity for 6 h, then transferred to a 70℃ constant temperature air drying oven for drying for 12 h, finally heated to 550℃ at a rate of 5℃ / min from room temperature, and calcined for 3 h to obtain the bauxite catalyst.

[0112] Comparative Example 5

[0113] The cerium dioxide catalyst of the present comparative example is processed from the following raw materials by weight: cerium dioxide 10 kg, starch 0.5 kg, polyvinyl alcohol (molecular weight 20000) 0.2 kg, and water 3 kg.

[0114] The preparation method of the cerium dioxide catalyst comprises the following steps: 10 kg of cerium dioxide, 0.5 kg of starch are fully mixed in a mixer for 5 h, then a mixture of 0.2 kg of polyvinyl alcohol and 3 kg of water is added for bonding, the kneaded green material is aged for 3 h, then transferred to a vacuum pug mill for further mixing for 3 h, and then added to a vacuum extruder, the extrusion pressure is 8 MPa, the extrusion operation is performed, the monolithic catalyst green body is obtained, then dried at 28℃ and 80% humidity for 6 h, then transferred to a 70℃ constant temperature air drying oven for drying for 12 h, finally heated to 550℃ at a rate of 5℃ / min from room temperature, and calcined for 3 h to obtain the cerium dioxide catalyst.

[0115] The physical diagram of the monolithic catalyst of the present application is shown in Figures 3-4 .

[0116] Figure 3 The physical diagrams of the monolithic catalysts CA1-550, CA2-550, CA3-550, CA4-550 and CS-550 of Example 2, 5, 8, 11 and Comparative Example 2 are shown in Figure 4 From the diagrams, it can be seen that all the catalysts are cylindrical, and the length is 3 cm and the diameter is 3 cm.

[0117] Figure 4 The physical diagram and specific size of the cerium-aluminum-based monolithic catalyst CA3-550 of Example 8 are shown in Figure 4 From the diagram, it can be seen that the length of the cerium-aluminum-based monolithic catalyst CA3-550 is 3 cm, and the diameter is 3 cm. It has 20 channels, and the diameter of each channel is 0.3 cm.

[0118] The performance of the monolithic catalysts of Examples 1-12 and Comparative Examples 1-5 was tested, and the test results are shown in Table 1 and Figures 5-7 The conversion rate of methyl ethyl ketone is defined as follows:

[0119]

[0120] wherein [methyl ethyl ketone] in represents the inlet concentration of methyl ethyl ketone in the reactor; and [methyl ethyl ketone] out represents the outlet concentration of methyl ethyl ketone in the reactor. in out wherein [methyl ethyl ketone] in represents the inlet concentration of methyl ethyl ketone in the reactor; and [methyl ethyl ketone] out represents the outlet concentration of methyl ethyl ketone in the reactor.

[0121] Figure 5 The XRD patterns of the monolithic catalysts of Examples 1-12 and Comparative Examples 1-3 are shown in Table 1. Figure 5 As can be seen from Table 1, the cerium-aluminum-based monolithic catalysts of the examples within the technical solution of the present application all contain Al2O3, SiO2 and CeO2 crystals.

[0122] Figure 6 The conversion rate of methyl ethyl ketone of the monolithic catalysts of Examples 1-12 and Comparative Examples 1-3 is shown in Table 1. Figure 6 As can be seen from Table 1, firstly, the cerium-aluminum-based monolithic catalysts of the examples within the technical solution of the present application all have certain catalytic oxidation effect on methyl ethyl ketone; secondly, when the mass ratio of bauxite to ceria in the cerium-aluminum-based monolithic catalyst is too high or too low, the conversion effect of the cerium-aluminum-based monolithic catalyst on methyl ethyl ketone is reduced; and the conversion effect of the monolithic catalyst using SiO2 and Al2O3 instead of bauxite on methyl ethyl ketone is relatively low.

[0123] As can be seen from the conversion rate of methyl ethyl ketone of Examples 1-12 and Comparative Examples 1-3, the conversion rate of methyl ethyl ketone of the monolithic catalysts CA1-550, CA2-550, CA3-550, CA4-550 and CS-550 obtained by calcining the green bodies CA1, CA2, CA3, CA4 and CS at 550°C is higher than that of the monolithic catalysts calcined at 450°C and 650°C, and the catalytic effect is better.

[0124] Figure 7 The conversion effect of the monolithic catalysts CA1-550, CA2-550, CA3-550, CA4-550, CS-550, bauxite catalyst and ceria catalyst of Examples 2, 5, 8, 11 and Comparative Examples 2, 4, 5 is shown in Table 1. Figure 7 (a) is the conversion rate of methyl ethyl ketone of the above examples and comparative examples, Figure 7 (b) is the T 90 and T 50 distribution diagram of the above examples and comparative examples, and Table 1 shows the T​90 and T 50 . wherein T 50 and T 90 represent the temperature at which the methyl ethyl ketone conversion is 50% and 90%, respectively.

[0125] Table 1 T 90 and T 50

[0126] T 50 (°C) T 90 (°C) Example 1 216 290 Example 2 211 255 Example 3 238 345 Example 4 192 219 Example 5 162 204 Example 6 208 239 Example 7 173 212 Example 8 145 177 Example 9 191 218 Example 10 172 215 Example 11 149 197 Example 12 202 228 Comparative Example 1 193 252 Comparative Example 2 172 233 Comparative Example 3 209 259 Comparative Example 4 ＞400 ＞400 Comparative Example 5 261 302

[0127] From Figure 7 It can be seen from (a) that the overall catalysts calcined at 550℃ are compared for methyl ethyl ketone conversion, among the prepared overall catalysts CA1-550, CA2-550, CA3-550, CA4-550, CS-550, bauxite catalyst and ceria catalyst, the cerium aluminum-based overall catalyst CA3-550 of Example 8 has better conversion effect on methyl ethyl ketone, the mass ratio of bauxite to ceria in the cerium aluminum-based overall catalyst CA1-550 of Example 2 is too high, which leads to the decrease of the conversion effect on methyl ethyl ketone, the conversion effect on methyl ethyl ketone of CS-550 using SiO2 and Al2O3 instead of bauxite is relatively low, and the catalysts using only bauxite (Comparative Example 4) or ceria (Comparative Example 5) have worse conversion effect on methyl ethyl ketone.

[0128] From Figure 7 (b) and Table 1, it can be seen that the cerium aluminum-based overall catalyst CA3-550 of Example 8 has the lowest T 50 and T 90 temperatures for methyl ethyl ketone, so in the embodiments of the present application, CA3-550 has the highest catalytic oxidation activity on methyl ethyl ketone.

[0129] As shown in Table 1, it can be seen from Examples 1-12 and Comparative Examples 1-3 that the overall catalysts obtained after calcination of the green bodies at 550℃ have lower T 50 and T 90 temperatures for methyl ethyl ketone than those calcined at 450℃ and 650℃, so the overall catalysts calcined at 550℃ have better catalytic effect on methyl ethyl ketone.

[0130] From Examples 2, 5, 8, 11 and Comparative Examples 2, 4, 5, it can be seen that when the mass ratio of bauxite to ceria in the cerium aluminum-based overall catalyst is too high or too low, the T 50 and T 90 temperatures for methyl ethyl ketone of the cerium aluminum-based overall catalyst become higher, and the conversion effect becomes worse; the T 50 and T90 The temperature also increased, and the conversion effect became worse; when only bauxite or only cerium dioxide was used instead of the composite of bauxite and cerium dioxide to prepare the monolithic catalyst, the T 50 and T 90 The temperature greatly increased, and the conversion effect was very poor.

[0131] Aspects, embodiments, features of the present application should be considered illustrative of all aspects, embodiments, features of the present application and not restrictive of the present application, the scope of which is only limited by the claims. Other embodiments, modifications, and uses will be apparent to those skilled in the art, and the embodiments herein are not intended to be exhaustive or limiting of the scope of the application. Variations in the order, processing procedures, and steps, combinations of steps or acts, and other modifications will suggest themselves to persons of ordinary skill in the art from the disclosure herein and are expressly contemplated as falling within the ambit of the present application.

[0132] In the preparation method of the present application, the order of each step is not limited to the order listed, and for those of ordinary skill in the art, changes in the order of each step without creative labor are within the protection scope of the present application. In addition, two or more steps or actions can be performed simultaneously.

[0133] Finally, it should be noted that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the embodiments of the present application. Those skilled in the art can make various modifications or supplements to the described specific embodiments or use similar ways to replace them, and it is not necessary or possible to fully describe all embodiments. Any obvious changes or variations derived from the essential spirit of the present application are still within the protection scope of the present application, and any additional limitation is contrary to the spirit of the present application.

Claims

1. Use of a cerium-aluminum based monolithic catalyst for the catalytic oxidation of methyl ethyl ketone, characterized in that, The cerium-aluminum-based monolithic catalyst has a T 50 of 150-200°C, a T 90 of 177-250°C; The cerium-aluminum-based monolithic catalyst is processed from raw materials including the following weight parts: bauxite 1-10 parts, ceria 1-10 parts, starch 0.1-5 parts, binder 0.01-1 parts, and water 0.1-10 parts.

2. Use according to claim 1, characterized in that, The bauxite is composed of the following components by weight parts: SiO2 20-50 parts, Al2O3 50-80 parts, Fe2O3 1-10 parts, TiO2 1-10 parts, K2O 0.1-10 parts, and CaO 0.1-10 parts.

3. Use according to claim 1, characterized in that, The mass ratio of the bauxite to ceria is (10-1):

1.

4. Use according to claim 1, characterized in that, The average particle size of the bauxite is 1-500 μm, and the average particle size of the ceria is 0.1-50 μm.

5. The use according to claim 1, characterized in that, The purity of the ceria is 90-100%.

6. Use according to claim 1, characterized in that, The binder includes one or more of polyvinyl alcohol, ammonium polyacrylate, polyurethane, and polyamide.

7. The use according to claim 1, characterized in that, The cerium-aluminum-based monolithic catalyst is cylindrical, with a length of 0.1-100 cm, a diameter of 0.1-100 cm, 5-50 axial channels, and the channels being cylindrical, each channel having a diameter of 0.1-1 cm.

8. The use according to claim 1, characterized in that, The cerium-aluminum-based monolithic catalyst has a specific surface area of 40 to 100 m 2 / g.

9. Use according to any one of claims 1 to 8, characterized in that, The preparation method of the cerium-aluminum-based monolithic catalyst includes the following steps: mixing the bauxite and ceria with the starch, adding a mixture of the binder and water to perform bonding, aging the bonded blank, further mixing, performing extrusion to obtain a monolithic catalyst green body, drying, and finally calcining to obtain the cerium-aluminum-based monolithic catalyst.

Images