Olefin deoxidation catalyst containing CeO2 as well as preparation method and application of olefin deoxidation catalyst

Abstract

The invention relates to the field of catalysts, and discloses a CeO2-containing olefin deoxidation catalyst as well as a preparation method and application thereof. The olefin deoxidation catalyst containing CeO2 comprises a carrier and an active component loaded on the carrier, the carrier contains CeO2 and an auxiliary agent, the auxiliary agent is selected from one or more than two of Mn oxide, Zn oxide, Na oxide and K oxide, and the active component is Pd oxide. The olefin deoxidation catalyst containing CeO2 has high catalytic activity, can perform deep deoxidation on olefin feed gas with low oxygen content, has the deoxidation rate up to 99.8%, and has a good application prospect in the aspect of olefin deoxidation.

Description

Technical Field

[0001] The present invention relates to the field of catalysts, and in particular to an olefin deoxidation catalyst containing CeO2, and a preparation method and application thereof. Background Art

[0002] Catalytic oxidation reaction is one of the most important reactions in the production of chemicals in the chemical production process. Propylene oxide is a very important organic compound raw material and the third largest propylene derivative after polypropylene and acrylonitrile. The hydrogen peroxide oxidation process (HPPO) has a simple process, high product purity and is environmentally friendly. It overcomes the high pollution defects of the traditional chlorohydrin method and solves the problem of complex process flow of the co-oxidation method. However, the HPPO technology involves a serious problem of high oxygen content produced by the decomposition of hydrogen peroxide during the reaction process, which makes the raw material propylene and other organic substances very easy to explode, making the oxidation reaction such as the HPPO process have great safety hazards. The petrochemical industry standard SH 3009-2013 clearly stipulates that "combustible gases with an oxygen content greater than 2% (v%)" should not be discharged into the whole plant's combustible gas emission system.

[0003] At present, the main treatment method for hydrocarbon oxygen-containing tail gas is inert gas dilution emission. Many domestic companies such as Changling Branch of Sinopec Corporation adopt the method of N2 mixed dilution, which not only increases operating costs (large amounts of nitrogen consumption) but also VOCs emissions cause environmental pollution. In recent years, catalytic deoxygenation is an effective deoxygenation method with great advantages in terms of economy, environmental protection, and energy saving. Therefore, it has been widely studied and widely used in industry. However, the deep deoxygenation of catalysts still has the problem of low efficiency. Therefore, the development of catalysts with high catalytic oxidation activity has become a research hotspot and difficulty for researchers.

[0004] Patent CN100513367C discloses a deoxidation catalyst with MnO / Mn3O4 as active components, and alkaline earth metal oxides and alumina as active promoters. The deoxidizer of the present invention can remove oxygen from propylene or ethylene with an oxygen content of 1-2000ppm. Under a reaction pressure of 0.4MPa, the oxygen content after deoxidation is less than 1ppm when the oxygen content is 1000ppm.

[0005] Patent CN106378144B discloses a manganese-based deoxidizer with cerium-based oxide as carrier, its preparation method and application. The catalyst consists of an active component, a carrier and a binder; wherein the active components are Cu and MnO, accounting for 35%-75% of the total weight of the catalyst; the carrier is CeO2 or CeO2-MOx composite oxide, accounting for 20%-50% of the total weight of the catalyst. Ethylene gas with an oxygen content of 1000ppm was introduced under a pressure of 0.4MPa for deoxidation experiments.

[0006] Patent CN1175478A (A high-strength, high heat-resistant and anti-poisoning deoxidation catalyst) discloses a high-strength and high heat-resistant catalyst for hydrogenation deoxidation in hydrogen, nitrogen and inert gases. This catalyst uses TiO2 as the main carrier, and the active components are noble metals palladium and / or platinum. The active components are loaded by the impregnation method and strengthened under a reducing atmosphere at high temperature (500 - 750 °C) to obtain the catalyst, and the noble metal content is 0.01 - 5.0%. This catalyst has high activity, and the deoxidation purification depth can reach 0.02 ppm. However, this catalyst requires high-temperature H2 reduction, increasing the cost and operation risk.

[0007] In the aspect of deoxidation catalyst modification, researchers have focused on how to modify the properties of noble metals, and the carriers mainly used are alumina, activated carbon, silica, molecular sieve or TiO2. There are relatively few studies on the design synthesis and deoxidation application of CeO2 carriers. Summary of the Invention

[0008] The object of the present invention is to overcome the problems of poor deoxidation effect and high cost of the existing olefin deoxidation catalyst containing CeO2, and to provide an olefin deoxidation catalyst containing CeO2. This olefin deoxidation catalyst containing CeO2 has high catalytic efficiency. When applied in olefin deoxidation, it can also perform deep deoxidation on olefin raw gas with low oxygen content, and requires lower reaction pressure and lower hydrogen content, making the operation more convenient.

[0009] To achieve the above object, on the one hand, the present invention provides an olefin deoxidation catalyst containing CeO2, which includes a carrier and an active component supported on the carrier;

[0010] The carrier contains CeO2 and an auxiliary agent, the auxiliary agent is selected from one or more of Mn oxide, Zn oxide, Na oxide and K oxide, and the active component is Pd oxide.

[0011] Preferably, the weight ratio of Pd oxide to CeO2 is 0.1 - 0.5:100, where Pd oxide is calculated as metal.

[0012] Preferably, the weight ratio of the auxiliary agent to CeO2 is 0.1 - 20:100, where the auxiliary agent is calculated as metal.

[0013] Preferably, the CeO2 is rod-shaped CeO2, cubic CeO2, octahedral CeO2 or polyhedral CeO2.

[0014] On the second aspect, the present invention provides a method for preparing an olefin deoxidation catalyst containing CeO2, which includes the following steps:

[0015] (1) Mix CeO₂ and the promoter precursor solution, and then conduct the first calcination;

[0016] (2) Load metal Pd onto the material obtained in step (1), and then conduct the second calcination;

[0017] The promoter precursor is selected from one or more of manganese salts, zinc salts, sodium salts, and potassium salts.

[0018] Preferably, the CeO₂ is rod-shaped CeO₂, cubic CeO₂, octahedral CeO₂, or polyhedral CeO₂.

[0019] Preferably, the preparation method of the rod-shaped CeO₂ includes: mixing a Ce salt aqueous solution and sodium hydroxide, then conducting crystallization, and then conducting calcination;

[0020] The conditions for the crystallization include: temperature is 60 - 150 °C, time is 10 - 50 h;

[0021] The conditions for the calcination include: temperature is 300 - 600 °C, time is 2 - 8 h.

[0022] Preferably, the preparation method of the cubic CeO₂ includes: mixing a Ce salt aqueous solution and sodium hydroxide, then conducting crystallization, and then conducting calcination;

[0023] The conditions for the crystallization include: temperature is 160 - 300 °C, time is 10 - 50 h;

[0024] The conditions for the calcination include: temperature is 300 - 600 °C, time is 2 - 8 h.

[0025] Preferably, the preparation method of the octahedral CeO₂ includes: mixing a Ce salt aqueous solution and Na₃PO₄, then conducting crystallization, and then conducting calcination;

[0026] The conditions for the crystallization include: temperature is 100 - 300 °C, time is 6 - 30 h;

[0027] The conditions for the calcination include: temperature is 300 - 600 °C, time is 2 - 8 h.

[0028] Preferably, the preparation method of the polyhedral CeO₂ includes: mixing a Ce salt aqueous solution, polyvinylpyrrolidone, and hydrazine hydrate, then conducting crystallization, and then conducting calcination;

[0029] The conditions for the crystallization include: temperature is 80 - 200 °C, time is 10 - 30 h;

[0030] The conditions for the calcination include: temperature is 300 - 600 °C, time is 2 - 8 h.

[0031] Preferably, in step (1), the weight ratio of the amount of the promoter precursor to that of CeO₂ is 0.1 - 20:100, where the promoter precursor is calculated as metal.

[0032] Preferably, the conditions for the first calcination include: temperature is 350 - 500 °C, and time is 3 - 6 h.

[0033] Preferably, in step (2), the weight ratio of the amount of metal Pd to that of CeO₂ is 0.1 - 0.5:100:100.

[0034] Preferably, in step (2), the loading method is selected from impregnation, ion sputtering, or electrochemical deposition.

[0035] Preferably, the conditions for the second calcination in step (2) include: temperature is 350 - 500 °C, and time is 3 - 6 h.

[0036] The third aspect of the present invention provides an olefin deoxygenation catalyst containing CeO₂ prepared by the above method.

[0037] The fourth aspect of the present invention provides the application of the above olefin deoxygenation catalyst containing CeO₂ in olefin deoxygenation reaction.

[0038] The fifth aspect of the present invention provides a method for olefin deoxygenation reaction, in which a raw material gas is contacted with a catalyst;

[0039] The raw material gas contains olefin, oxygen, and hydrogen; the catalyst is the above olefin deoxygenation catalyst containing CeO₂.

[0040] Preferably, the content of oxygen in the raw material gas is ≤ 0.25 vol%, and the volume ratio of hydrogen to oxygen is ≤ 4.

[0041] Preferably, the conditions for the contact include: space velocity is 2000 - 5000 h -1 , pressure is 0.1 - 0.4 MPa, and temperature is 100 - 200 °C.

[0042] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0043] (1) The catalytic efficiency of the olefin deoxygenation catalyst containing CeO₂ of the present invention is high. This may be because the CeO₂ in the olefin deoxygenation catalyst containing CeO₂ has efficient oxygen vacancies, which promotes the adsorption and activation ability of oxygen. The Pd oxide of the active component is highly dispersed, and at the same time, the promoter contained in the carrier promotes the interaction between the Pd oxide of the active component and the carrier, thereby improving the catalytic activity;

[0044] (2) The cost of the olefin deoxygenation catalyst containing CeO₂ of the present invention is relatively low, which is mainly due to the high utilization rate of metal Pd in the preparation process.

[0045] (3) When the olefin deoxidation catalyst containing CeO₂ of the present invention is applied in the olefin deoxidation reaction, the required reaction pressure and the required hydrogen content are relatively low, and the operation is more convenient. Detailed Embodiments

[0046] The following provides a detailed description of the specific embodiments of the present invention. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention and are not used to limit the present invention.

[0047] In the ranges disclosed herein, the endpoints and any values are not limited to the exact ranges or values. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0048] On the one hand, the present invention provides an olefin deoxidation catalyst containing CeO₂. The olefin deoxidation catalyst containing CeO₂ includes a carrier and an active component supported on the carrier;

[0049] The carrier contains CeO₂ and a promoter. The promoter is selected from one or more of Mn oxide, Zn oxide, Na oxide, and K oxide, and the active component is Pd oxide.

[0050] In a preferred embodiment, in order to improve the interaction between the active component Pd oxide and the carrier and improve the catalytic activity, the weight ratio of Pd oxide to CeO₂ is 0.1 - 0.5:100, where Pd oxide is calculated as metal; specifically, it can be 0.1:100, 0.2:100, 0.3:100, 0.4:100, or 0.5:100.

[0051] In a preferred embodiment, in order to further promote the interaction between the active component Pd oxide and the carrier, promote oxygen adsorption while promoting the activation of hydrogen, and thus further improve the catalytic activity, the weight ratio of the promoter to CeO₂ is 0.1 - 20:100, where the promoter is calculated as metal; specifically, it can be 0.1:100, 5:100, 10:100, 15:100, or 20:100.

[0052] In a preferred embodiment, in order to better promote the interaction between the active component Pd oxide and CeO₂, the CeO₂ is rod-shaped CeO₂, cubic CeO₂, octahedral CeO₂, or polyhedral CeO₂.

[0053] The olefin deoxidation catalyst containing CeO2 described in the present invention has high catalytic activity, mainly because CeO2 has efficient oxygen vacancies, which promotes the adsorption and activation ability of oxygen. The promoter contained on the carrier promotes the interaction between Pd oxide and the carrier containing CeO2, promotes the adsorption of oxygen and also promotes the activation of hydrogen, thereby improving the catalytic activity of the catalyst.

[0054] The second aspect of the present invention provides a method for preparing an olefin deoxidation catalyst containing CeO2, which method comprises the following steps:

[0055] (1) Mix CeO2 and a promoter precursor solution, and then perform a first calcination;

[0056] (2) Load metal Pd onto the material obtained in step (1), and then perform a second calcination;

[0057] The promoter precursor is selected from one or more of manganese salts, zinc salts, sodium salts, and potassium salts.

[0058] In a preferred embodiment, in order to better promote the interaction between metal Pd and CeO2, the CeO2 is rod-shaped CeO2, cubic CeO2, octahedral CeO2, or polyhedral CeO2.

[0059] In a preferred embodiment, the method for preparing rod-shaped CeO2 comprises: mixing a Ce salt aqueous solution and sodium hydroxide, followed by crystallization, and then calcination;

[0060] The conditions for the calcination include: a temperature of 300 - 600 °C and a time of 2 - 8 h.

[0061] In a preferred embodiment, the crystallization conditions for preparing rod-shaped CeO2 include: a temperature of 60 - 150 °C and a time of 10 - 50 h; specifically, the temperature can be 60 °C, 80 °C, 100 °C, 120 °C, or 150 °C; the time can be 10 h, 20 h, 24 h, 30 h, 40 h, or 50 h.

[0062] In a preferred embodiment, the method for preparing rod-shaped CeO2 further comprises performing solid-liquid separation, washing, and drying treatments after crystallization and before calcination; there are no special requirements for the specific treatment methods of solid-liquid separation, washing, and drying, and conventional usage methods in the art can be used. For example, deionized water and absolute ethanol can be used to wash the solid intermediate material after solid-liquid separation; the drying conditions include: a temperature of 80 - 120 °C and a time of 8 - 24 h.

[0063] In a specific embodiment, the method for preparing the rod-shaped CeO2 is as follows: Ce(NO3)3·6H2O, water, and sodium hydroxide are mixed and stirred, and then the mixed solution is placed in a stainless-steel autoclave with a polytetrafluoroethylene lining for crystallization, followed by solid-liquid separation, washing, and drying, and finally calcination.

[0064] In a preferred embodiment, the method for preparing the cubic CeO2 includes: mixing an aqueous Ce salt solution and sodium hydroxide for crystallization, and then performing calcination;

[0065] The conditions for the calcination include: a temperature of 300 - 600 °C and a time of 2 - 8 h.

[0066] In a preferred embodiment, the crystallization conditions for preparing the cubic CeO2 include: a temperature of 160 - 300 °C and a time of 10 - 50 h; specifically, the temperature can be 160 °C, 180 °C, 200 °C, 220 °C, 240 °C, 260 °C, 280 °C, or 300 °C; and the time can be 10 h, 20 h, 24 h, 30 h, 40 h, or 50 h.

[0067] In a preferred embodiment, the method for preparing the cubic CeO2 further includes performing solid-liquid separation, washing, and drying treatments after crystallization and before calcination; there are no special requirements for the specific treatment methods of solid-liquid separation, washing, and drying, and any conventional usage in the art can be used. For example, deionized water and absolute ethanol can be used to wash the solid intermediate material after solid-liquid separation; the drying conditions include: a temperature of 80 - 120 °C and a time of 8 - 24 h.

[0068] In a specific embodiment, the method for preparing the cubic CeO2 is as follows: Ce(NO3)3·6H2O, water, and sodium hydroxide are mixed and stirred, and then the mixed solution is placed in a stainless-steel autoclave with a polytetrafluoroethylene lining for crystallization, followed by solid-liquid separation, washing, and drying, and finally calcination.

[0069] In a preferred embodiment, the method for preparing the octahedral CeO2 includes: mixing an aqueous Ce salt solution and Na3PO4 for crystallization, and then performing calcination;

[0070] The conditions for the calcination include: a temperature of 300 - 600 °C and a time of 2 - 8 h.

[0071] In a preferred embodiment, the crystallization conditions for preparing the octahedral CeO2 include: a temperature of 100 - 300 °C and a time of 6 - 30 h; specifically, the temperature can be 100 °C, 150 °C, 170 °C, 200 °C, 250 °C, or 300 °C; and the time can be 6 h, 10 h, 15 h, 20 h, 25 h, or 30 h.

[0072] In a preferred embodiment, the method for preparing the octahedral CeO2 further includes solid-liquid separation, washing, and drying treatments after crystallization and before calcination; there are no special requirements for the specific treatment methods of solid-liquid separation, washing, and drying, and conventional usage methods in the art can be used. For example, deionized water and absolute ethanol can be used to wash the solid intermediate material after solid-liquid separation; the drying conditions include: a temperature of 80-120 °C and a time of 8-24 h.

[0073] In a specific embodiment, the method for preparing the octahedral CeO2 is as follows: Ce(NO3)3·6H2O, water, and Na3PO4 are mixed and stirred, and then the mixed solution is placed in a stainless-steel autoclave lined with polytetrafluoroethylene for crystallization, followed by solid-liquid separation, washing, and drying, and finally calcination.

[0074] Preferably, the method for preparing the polyhedral CeO2 includes: mixing an aqueous Ce salt solution, polyvinylpyrrolidone, and hydrazine hydrate for crystallization, and then performing calcination;

[0075] The conditions for the calcination include: a temperature of 300-600 °C and a time of 2-8 h.

[0076] In a preferred embodiment, the crystallization conditions for preparing the polyhedral CeO2 include: a temperature of 80-200 °C and a time of 10-30 h; specifically, the temperature can be 80 °C, 100 °C, 120 °C, 140 °C, 160 °C, 180 °C, or 200 °C; the time can be 10 h, 12 h, 15 h, 20 h, 24 h, or 30 h.

[0077] In a preferred embodiment, the method for preparing the polyhedral CeO2 further includes solid-liquid separation, washing, and drying treatments after crystallization and before calcination; there are no special requirements for the specific treatment methods of solid-liquid separation, washing, and drying, and conventional usage methods in the art can be used. For example, deionized water and absolute ethanol can be used to wash the solid intermediate material after solid-liquid separation; the drying conditions include: a temperature of 80-120 °C and a time of 8-24 h.

[0078] In a specific embodiment, the method for preparing the polyhedral CeO2 is as follows: Ce(NO3)3·6H2O, water, polyvinylpyrrolidone, and hydrazine hydrate are mixed and stirred, and then the mixed solution is placed in a stainless-steel autoclave lined with polytetrafluoroethylene for crystallization, followed by solid-liquid separation, washing, and drying, and finally calcination.

[0079] In the present invention, there are no special requirements for the Ce salt, and any water-soluble Ce salt commonly used in the art can be used. For example, it can be one or more of Ce(NO3)3·6H2O, Ce(NO3)3, CeCl3·7H2O, and CeCl3.

[0080] In the present invention, there are no special requirements for the mass concentration of hydrazine hydrate, and any ammonia water concentration commonly used in the art can be used. For example, it can be 70%, 75%, 80%, or 85%.

[0081] In the method of the present invention, there are no special requirements for the manganese salt, zinc salt, sodium salt, and potassium salt, and any soluble manganese salt, zinc salt, sodium salt, and potassium salt commonly used in the art can be used. For example, the manganese salt can be manganese nitrate, manganese chloride, or manganese sulfate; the zinc salt can be zinc nitrate, zinc chloride, or zinc sulfate; the sodium salt can be sodium nitrate, sodium sulfate, or sodium chloride; the potassium salt can be potassium nitrate, potassium chloride, or potassium sulfate.

[0082] In a preferred embodiment, in step (1), CeO2 and the promoter precursor solution are mixed by impregnation.

[0083] In a preferred embodiment, in step (1), in order to better adjust the electronic properties of metal Pd, further promote the interaction between Pd oxide and CeO2, better promote the adsorption of oxygen and the activation of hydrogen, and thus improve the catalytic activity, the weight ratio of the amount of the promoter precursor to CeO2 is 0.1 - 20:100, where the promoter precursor is calculated as metal; specifically, it can be 0.1:100, 5:100, 10:100, 15:100, or 20:100.

[0084] In a preferred embodiment, step (1) further includes a drying treatment after mixing and before the first calcination. The drying conditions include: temperature is 120 - 180 °C, and time is 10 - 24 h.

[0085] In a preferred embodiment, the conditions of the first calcination include: temperature is 350 - 500 °C, and time is 3 - 6 h; specifically, the temperature can be 350 °C, 400 °C, 450 °C, or 500 °C; the time can be 3 h, 4 h, 5 h, or 6 h.

[0086] In a preferred embodiment, in step (2), in order to improve the interaction between metal Pd and CeO2 and improve the catalytic activity, in step (2), the weight ratio of the amount of metal Pd to CeO2 is 0.1 - 0.5:100; specifically, it can be 0.1:100, 0.2:100, 0.3:100, 0.4:100, or 0.5:100.

[0087] In a preferred embodiment, in order to improve the utilization rate and dispersion of metallic Pd, thereby enhancing the catalytic activity, in step (2), the loading method is selected from impregnation, ion sputtering, or electrochemical deposition.

[0088] In a more preferred embodiment, in step (2), the loading method is electrochemical deposition. A two-electrode system is used in an electrolytic cell at 25 °C for cathodic constant-current electrochemical deposition, enabling metallic Pd to be highly dispersed on the support containing CeO2. While improving the utilization rate of metallic Pd, it further enhances its dispersion, thereby reducing the operating cost and promoting the interaction between the active component Pd oxide and the support containing CeO2, promoting oxygen adsorption while promoting the activation of hydrogen, and thus enhancing the catalytic activity.

[0089] In a preferred embodiment, in step (2), the conditions for the second calcination include: a temperature of 350 - 500 °C and a time of 3 - 6 h; specifically, the temperature can be 350 °C, 400 °C, 450 °C, or 500 °C; the time can be 3 h, 4 h, 5 h, or 6 h.

[0090] The olefin deoxygenation catalyst containing CeO2 prepared by the above method has high catalytic efficiency. This is mainly because CeO2 has efficient oxygen vacancies, which promotes the adsorption and activation of oxygen. The additives contained in the support can also regulate the electronic properties of metallic Pd, thereby promoting the interaction between Pd oxide and the support containing CeO2, promoting oxygen adsorption while also promoting the activation of hydrogen, and further enhancing the catalytic activity.

[0091] The third aspect of the present invention provides an olefin deoxygenation catalyst containing CeO2 prepared by the above method.

[0092] The fourth aspect of the present invention provides the application of the above olefin deoxygenation catalyst containing CeO2 in olefin deoxygenation reactions.

[0093] When the olefin deoxygenation catalyst containing CeO2 described in the present invention is applied in olefin deoxygenation reactions, it has high catalytic efficiency. This is mainly because in the olefin deoxygenation catalyst containing CeO2 described in the present invention, metallic Pd is highly dispersed on the support containing CeO2, promoting the interaction between the active component Pd oxide and the support containing CeO2, promoting oxygen adsorption while also promoting the activation of hydrogen, enhancing the catalytic activity, and further increasing the deoxygenation efficiency.

[0094] The fifth aspect of the present invention provides a method for olefin deoxygenation reactions, wherein a raw material gas is contacted with a catalyst;

[0095] The raw material gas contains olefins, oxygen, and hydrogen; the catalyst is the above olefin deoxygenation catalyst containing CeO2.

[0096] The olefin deoxidation catalyst containing CeO2 according to the present invention has a good deoxidation effect on the feed gas with a relatively low oxygen content and a relatively small volume ratio of hydrogen to oxygen, and has less stringent requirements for environmental conditions. It still has a good deoxidation effect under low pressure and relatively low temperature, and the deoxidation rate is above 90%, up to 99.76% at most.

[0097] In a preferred embodiment, the olefin is ethylene and / or propylene.

[0098] In a preferred embodiment, the content of oxygen in the feed gas is ≤ 0.25% by volume, and the volume ratio of hydrogen to oxygen is ≤ 4; specifically, the content of oxygen can be 0.25% by volume, 0.2% by volume, 0.15% by volume, 0.1% by volume or 0.05% by volume; the volume ratio of hydrogen to oxygen can be 4, 3, 2 or 1.

[0099] In the present invention, "space velocity" all refers to "volume space velocity", and the pressure all refers to absolute pressure.

[0100] In a preferred embodiment, the conditions of the contact include: the space velocity is 2000 - 5000 h -1 , the pressure is 0.1 - 0.4 MPa, and the temperature is 100 - 200 °C; specifically, the space velocity can be 2000 h -1 , 3000 h -1 , 4000 h -1 or 5000 h -1 ; the pressure can be 0.1 MPa, 0.2 MPa, 0.3 MPa or 0.4 MPa; the temperature can be 100 °C, 120 °C, 140 °C, 160 °C, 180 °C or 200 °C.

[0101] The following further illustrates an olefin deoxidation catalyst containing CeO2 according to the present invention, its preparation method and application through examples. The examples are implemented on the premise of the technical solution of the present invention, and detailed implementation manners and specific operation processes are given, but the protection scope of the present invention is not limited to the following examples.

[0102] The experimental methods in the following examples are all conventional methods in the art unless otherwise specified. The experimental materials used in the following examples can all be commercially obtained unless otherwise specified.

[0103] Example 1

[0104] (1) Mix 3.472 g of Ce(NO3)3·6H2O with 20 mL of deionized water to form a Ce(NO3)3 solution. Mix 38.4 g of NaOH with 140 mL of deionized water to form a NaOH solution. Mix the Ce(NO3)3 solution and the NaOH solution and stir for 0.5 h. Then place the mixed solution in a 250 mL stainless steel autoclave with a PTFE liner at 100 °C for crystallization for 24 h. Then carry out solid-liquid separation, wash the solid intermediate material with deionized water and absolute ethanol, then dry in an oven at 80 °C for 8 h, and finally calcine in a tubular furnace at 400 °C for 4 h to finally obtain rod-shaped CeO2;

[0105] Immerse the rod-shaped CeO2 into an aqueous solution of Mn(NO3)2, then dry at 120 °C for 10 h, and finally carry out the first calcination in a tubular furnace at a temperature of 400 °C for 4 h, where the weight ratio of the amount of Mn(NO3)2 (calculated as metal) to the rod-shaped CeO2 is 10:100;

[0106] (2) Use a two-electrode system to carry out cathode constant current electrodeposition in a 50 ml electrolytic cell, where the cathode is the rod-shaped CeO2 prepared in step (1), and the electrolyte is a solution containing metal Pd ions; the working temperature is 25 °C, and the weight ratio of the amount of metal Pd to the rod-shaped CeO2 is 0.1:100, and then carry out the second calcination at a temperature of 400 °C for 4 h.

[0107] Example 2

[0108] (1) Mix 3.472 g of Ce(NO3)3·6H2O with 20 mL of deionized water to form a Ce(NO3)3 solution. Mix 38.4 g of NaOH with 140 mL of deionized water to form a NaOH solution. Mix the Ce(NO3)3 solution and the NaOH solution and stir for 0.5 h. Then place the mixed solution in a 250 mL stainless steel autoclave with a PTFE liner at 100 °C for crystallization for 24 h. Then carry out solid-liquid separation, wash the solid intermediate material with deionized water and absolute ethanol, then dry in an oven at 80 °C for 8 h, and finally calcine in a tubular furnace at 400 °C for 4 h to finally obtain rod-shaped CeO2;

[0109] Immerse the rod-shaped CeO2 into an aqueous solution of Zn(NO3)2, then dry at 120 °C for 10 h, and finally carry out the first calcination in a tubular furnace at a temperature of 400 °C for 4 h, where the weight ratio of the amount of Zn(NO3)2 (calculated as metal) to the rod-shaped CeO2 is 10:100;

[0110] (2) A cathode constant current electrodeposition is carried out in a 50 ml electrolytic cell using a two - electrode system, where the cathode is the rod - shaped CeO2 prepared in step (1), and the electrolyte is a solution containing metal Pd ions; the working temperature is 25 °C, the weight ratio of metal Pd to the rod - shaped CeO2 is 0.1:100, and then a second calcination is carried out, with the calcination temperature being 400 °C and the time being 4 h.

[0111] Example 3

[0112] (1) Mix 3.472 g of Ce(NO3)3·6H2O with 20 mL of deionized water to form a Ce(NO3)3 solution, mix 38.4 g of NaOH with 140 mL of deionized water to form a NaOH solution, mix the Ce(NO3)3 solution and the NaOH solution and stir for 0.5 h, then place the mixed solution in a 250 mL stainless - steel autoclave with a Teflon lining at 100 °C for crystallization for 24 h, then carry out solid - liquid separation, wash the solid intermediate material with deionized water and absolute ethanol, then dry it in an oven at 80 °C for 8 h, and finally calcine it in a tube furnace at 400 °C for 4 h to finally obtain rod - shaped CeO2;

[0113] Immerse the rod - shaped CeO2 into an aqueous NaNO3 solution, then dry it at 120 °C for 10 h, and finally carry out the first calcination in a tube furnace, with the first calcination temperature being 400 °C and the time being 4 h, where the weight ratio of NaNO3 (calculated as metal) to the rod - shaped CeO2 is 10:100;

[0114] (2) A cathode constant current electrodeposition is carried out in a 50 ml electrolytic cell using a two - electrode system, where the cathode is the rod - shaped CeO2 prepared in step (1), and the electrolyte is a solution containing metal Pd ions; the working temperature is 25 °C, the weight ratio of metal Pd to the rod - shaped CeO2 is 0.1:100, and then a second calcination is carried out, with the calcination temperature being 400 °C and the time being 4 h.

[0115] Example 4

[0116] (1) Mix 3.472 g of Ce(NO3)3·6H2O with 20 mL of deionized water to form a Ce(NO3)3 solution, mix 38.4 g of NaOH with 140 mL of deionized water to form a NaOH solution, mix the Ce(NO3)3 solution and the NaOH solution and stir for 0.5 h, then place the mixed solution in a 250 mL stainless - steel autoclave with a Teflon lining at 100 °C for crystallization for 24 h, then carry out solid - liquid separation, wash the solid intermediate material with deionized water and absolute ethanol, then dry it in an oven at 80 °C for 8 h, and finally calcine it in a tube furnace at 400 °C for 4 h to finally obtain rod - shaped CeO2;

[0117] The rod-shaped CeO₂ was impregnated into an aqueous solution of KNO₃, then dried at 120 °C for 10 h, and finally subjected to the first calcination in a tubular furnace at a temperature of 400 °C for 4 h. Among them, the weight ratio of KNO₃ (calculated as metal) to the amount of rod-shaped CeO₂ used was 10:100;

[0118] (2) Cathodic constant-current electrodeposition was carried out in a 50 ml electrolytic cell using a two-electrode system. The cathode was the rod-shaped CeO₂ prepared in step (1), and the electrolyte was a solution containing metal Pd ions; the working temperature was 25 °C, and the weight ratio of metal Pd to the amount of rod-shaped CeO₂ used was 0.1:100. Then, the second calcination was carried out at a temperature of 400 °C for 4 h.

[0119] Example 5

[0120] (1) 3.472 g of Ce(NO₃)₃·6H₂O was mixed with 20 mL of deionized water to form a Ce(NO₃)₃ solution. 38.4 g of NaOH was mixed with 140 mL of deionized water to form an NaOH solution. The Ce(NO₃)₃ solution and the NaOH solution were mixed and stirred for 0.5 h. Then, the mixed solution was placed in a 250 mL stainless-steel autoclave with a polytetrafluoroethylene lining at 180 °C for crystallization for 24 h. Then, solid-liquid separation was carried out, and the solid-phase intermediate material was washed with deionized water and absolute ethanol, and then dried in an oven at 80 °C for 8 h. Finally, it was calcined in a tubular furnace at 400 °C for 4 h to finally obtain cubic CeO₂;

[0121] The cubic CeO₂ was impregnated into an aqueous solution of Mn(NO₃)₂, then dried at 120 °C for 10 h, and finally subjected to the first calcination in a tubular furnace at a temperature of 400 °C for 4 h. Among them, the weight ratio of Mn(NO₃)₂ (calculated as metal) to the amount of cubic CeO₂ used was 10:100;

[0122] (2) Cathodic constant-current electrodeposition was carried out in a 50 ml electrolytic cell using a two-electrode system. The cathode was the cubic CeO₂ prepared in step (1), and the electrolyte was a solution containing metal Pd ions; the working temperature was 25 °C, and the weight ratio of metal Pd to the amount of cubic CeO₂ used was 0.1:100. Then, the second calcination was carried out at a temperature of 400 °C for 4 h.

[0123] Example 6

[0124] (1) Mix 3.472 g of Ce(NO3)3·6H2O with 20 mL of deionized water to form a Ce(NO3)3 solution. Mix 38.4 g of NaOH with 140 mL of deionized water to form a NaOH solution. Mix the Ce(NO3)3 solution and the NaOH solution and stir for 0.5 h. Then place the mixed solution in a 250 mL stainless steel autoclave with a Teflon lining at 180 °C for crystallization for 24 h. Then perform solid-liquid separation, wash the solid intermediate material with deionized water and absolute ethanol, then dry it in an oven at 80 °C for 8 h, and finally calcine it in a tubular furnace at 400 °C for 4 h to finally obtain cubic CeO2;

[0125] Immerse the cubic CeO2 into an aqueous Zn(NO3)2 solution, then dry it at 120 °C for 10 h, and finally perform the first calcination in a tubular furnace at a temperature of 400 °C for 4 h. Among them, the weight ratio of Zn(NO3)2 (calculated as metal) to the amount of cubic CeO2 used is 10:100;

[0126] (2) Use a two-electrode system to perform cathodic constant current electrodeposition in a 50 ml electrolytic cell, where the cathode is the cubic CeO2 prepared in step (1), and the electrolyte is a solution containing metal Pd ions; the working temperature is 25 °C, and the weight ratio of metal Pd to the amount of cubic CeO2 used is 0.1:100. Then perform the second calcination at a temperature of 400 °C for 4 h.

[0127] Example 7

[0128] (1) Mix 3.472 g of Ce(NO3)3·6H2O with 20 mL of deionized water to form a Ce(NO3)3 solution. Mix 38.4 g of NaOH with 140 mL of deionized water to form a NaOH solution. Mix the Ce(NO3)3 solution and the NaOH solution and stir for 0.5 h. Then place the mixed solution in a 250 mL stainless steel autoclave with a Teflon lining at 180 °C for crystallization for 24 h. Then perform solid-liquid separation, wash the solid intermediate material with deionized water and absolute ethanol, then dry it in an oven at 80 °C for 8 h, and finally calcine it in a tubular furnace at 400 °C for 4 h to finally obtain cubic CeO2;

[0129] Immerse the cubic CeO2 into an aqueous NaNO3 solution, then dry it at 120 °C for 10 h, and finally perform the first calcination in a tubular furnace at a temperature of 400 °C for 4 h. Among them, the weight ratio of NaNO3 (calculated as metal) to the amount of cubic CeO2 used is 10:100;

[0130] (2) Use a two - electrode system to perform cathodic constant - current electrodeposition in a 50 - ml electrolytic cell. The cathode is the cubic CeO₂ prepared in step (1), and the electrolyte is a solution containing metal Pd ions. The working temperature is 25 °C, and the weight ratio of metal Pd to the cubic CeO₂ is 0.1:100. Then, perform the second calcination at a temperature of 400 °C for 4 h.

[0131] Example 8

[0132] (1) Mix 3.472 g of Ce(NO₃)₃·6H₂O with 20 mL of deionized water to form a Ce(NO₃)₃ solution. Mix 38.4 g of NaOH with 140 mL of deionized water to form an NaOH solution. Mix the Ce(NO₃)₃ solution and the NaOH solution and stir for 0.5 h. Then, place the mixed solution in a 250 - mL stainless - steel autoclave with a polytetrafluoroethylene lining at 180 °C for crystallization for 24 h. Then, perform solid - liquid separation, wash the solid intermediate material with deionized water and absolute ethanol, then dry it in an oven at 80 °C for 8 h, and finally calcine it in a tubular furnace at 400 °C for 4 h to finally obtain cubic CeO₂;

[0133] Immerse the cubic CeO₂ in an aqueous KNO₃ solution, then dry it at 120 °C for 10 h, and finally perform the first calcination in a tubular furnace at a temperature of 400 °C for 4 h. Among them, the weight ratio of KNO₃ (calculated as metal) to the cubic CeO₂ is 10:100;

[0134] (2) Use a two - electrode system to perform cathodic constant - current electrodeposition in a 50 - ml electrolytic cell. The cathode is the cubic CeO₂ prepared in step (1), and the electrolyte is a solution containing metal Pd ions. The working temperature is 25 °C, and the weight ratio of metal Pd to the cubic CeO₂ is 0.1:100. Then, perform the second calcination at a temperature of 400 °C for 4 h.

[0135] Example 9

[0136] (1) Mix 1.716 g of Ce(NO₃)₃·6H₂O with 20 mL of deionized water to form a Ce(NO₃)₃ solution. Mix 0.015 g of Na₃PO₄ with 140 mL of deionized water to form an Na₃PO₄ solution. Mix the Ce(NO₃)₃ solution and the Na₃PO₄ solution and stir for 0.5 h. Then, place the mixed solution in a 250 - mL stainless - steel autoclave with a polytetrafluoroethylene lining at 170 °C for crystallization for 10 h. Then, perform solid - liquid separation, wash the solid intermediate material with deionized water and absolute ethanol, then dry it in an oven at 80 °C for 8 h, and finally calcine it in a tubular furnace at 400 °C for 4 h to finally obtain octahedral CeO₂;

[0137] The octahedral CeO₂ was impregnated into an aqueous solution of Mn(NO₃)₂, then dried at 120 °C for 10 h, and finally subjected to a first calcination in a tubular furnace at a temperature of 400 °C for 4 h. Among them, the weight ratio of the dosage of Mn(NO₃)₂ (calculated as metal) to octahedral CeO₂ was 10:100;

[0138] (2) A cathode constant current electrodeposition was carried out in a 50 ml electrolytic cell using a two - electrode system. The cathode was the octahedral CeO₂ prepared in step (1), and the electrolyte was a solution containing metal Pd ions; the working temperature was 25 °C, and the weight ratio of the dosage of metal Pd to octahedral CeO₂ was 0.1:100. Then, a second calcination was carried out at a temperature of 400 °C for 4 h.

[0139] Example 10

[0140] (1) 1.716 g of Ce(NO₃)₃·6H₂O was mixed with 20 mL of deionized water to form a Ce(NO₃)₃ solution, 0.015 g of Na₃PO₄ was mixed with 140 mL of deionized water to form a Na₃PO₄ solution. The Ce(NO₃)₃ solution and the Na₃PO₄ solution were mixed and stirred for 0.5 h, and then the mixed solution was placed in a 250 mL stainless - steel autoclave with a polytetrafluoroethylene lining at 170 °C for crystallization for 10 h. Then, solid - liquid separation was carried out, and the solid - phase intermediate material was washed with deionized water and absolute ethanol, and then dried in an oven at 80 °C for 8 h, and finally calcined in a tubular furnace at 400 °C for 4 h to finally obtain octahedral CeO₂;

[0141] The octahedral CeO₂ was impregnated into an aqueous solution of Zn(NO₃)₂, then dried at 120 °C for 10 h, and finally subjected to a first calcination in a tubular furnace at a temperature of 400 °C for 4 h. Among them, the weight ratio of the dosage of Zn(NO₃)₂ (calculated as metal) to octahedral CeO₂ was 10:100;

[0142] (2) A cathode constant current electrodeposition was carried out in a 50 ml electrolytic cell using a two - electrode system. The cathode was the octahedral CeO₂ prepared in step (1), and the electrolyte was a solution containing metal Pd ions; the working temperature was 25 °C, and the weight ratio of the dosage of metal Pd to octahedral CeO₂ was 0.1:100. Then, a second calcination was carried out at a temperature of 400 °C for 4 h.

[0143] Example 11

[0144] (1) Mix 1.716 g of Ce(NO3)3·6H2O with 20 mL of deionized water to form a Ce(NO3)3 solution. Mix 0.015 g of Na3PO4 with 140 mL of deionized water to form a Na3PO4 solution. Mix the Ce(NO3)3 solution and the Na3PO4 solution and stir for 0.5 h. Then place the mixed solution in a 250 mL stainless steel autoclave with a PTFE lining at 170 °C for crystallization for 10 h. Then perform solid-liquid separation, wash the solid intermediate material with deionized water and absolute ethanol, then dry in an oven at 80 °C for 8 h, and finally calcine in a tube furnace at 400 °C for 4 h to finally obtain octahedral CeO2;

[0145] Immerse the octahedral CeO2 into an aqueous NaNO3 solution, then dry at 120 °C for 10 h, and finally perform the first calcination in a tube furnace at a temperature of 400 °C for 4 h, where the weight ratio of NaNO3 (calculated as metal) to the amount of octahedral CeO2 used is 10:100;

[0146] (2) Use a two-electrode system to perform cathodic constant current electrodeposition in a 50 ml electrolytic cell, where the cathode is the octahedral CeO2 prepared in step (1), and the electrolyte is a solution containing metal Pd ions; the working temperature is 25 °C, the weight ratio of metal Pd to the amount of octahedral CeO2 used is 0.1:100, and then perform the second calcination at a temperature of 400 °C for 4 h.

[0147] Example 12

[0148] (1) Mix 1.716 g of Ce(NO3)3·6H2O with 20 mL of deionized water to form a Ce(NO3)3 solution. Mix 0.015 g of Na3PO4 with 140 mL of deionized water to form a Na3PO4 solution. Mix the Ce(NO3)3 solution and the Na3PO4 solution and stir for 0.5 h. Then place the mixed solution in a 250 mL stainless steel autoclave with a PTFE lining at 170 °C for crystallization for 10 h. Then perform solid-liquid separation, wash the solid intermediate material with deionized water and absolute ethanol, then dry in an oven at 80 °C for 8 h, and finally calcine in a tube furnace at 400 °C for 4 h to finally obtain octahedral CeO2;

[0149] Immerse the octahedral CeO2 into an aqueous KNO3 solution, then dry at 120 °C for 10 h, and finally perform the first calcination in a tube furnace at a temperature of 400 °C for 4 h, where the weight ratio of KNO3 (calculated as metal) to the amount of octahedral CeO2 used is 10:100;

[0150] (2) A cathode constant current electrodeposition was carried out in a 50 ml electrolytic cell using a two - electrode system, where the cathode was the octahedral CeO₂ prepared in step (1), and the electrolyte was a solution containing metal Pd ions; the working temperature was 25 °C, the weight ratio of metal Pd to octahedral CeO₂ was 0.1:100, and then a second calcination was carried out at a temperature of 400 °C for 4 h.

[0151] Example 13

[0152] (1) 5.208 g of Ce(NO₃)₃·6H₂O was mixed with 60 mL of deionized water to form a Ce(NO₃)₃ solution, then 1.5 g of polyvinylpyrrolidone was added and stirred for 20 min, then 12 mL of 85% by mass N₂H₄·H₂O was added and stirred for 15 min, and then the mixed solution was placed in a 250 mL stainless - steel autoclave with a polytetrafluoroethylene lining at 180 °C for crystallization for 12 h. Then, solid - liquid separation was carried out, and the solid intermediate material was washed with deionized water and absolute ethanol, then dried in an oven at 80 °C for 8 h, and finally calcined in a tube furnace at 400 °C for 4 h to finally obtain polyhedral CeO₂;

[0153] The polyhedral CeO₂ was impregnated into an aqueous solution of Mn(NO₃)₂, then dried at 120 °C for 10 h, and finally a first calcination was carried out in a tube furnace at a temperature of 400 °C for 4 h, where the weight ratio of Mn(NO₃)₂ (calculated as metal) to polyhedral CeO₂ was 10:100;

[0154] (2) A cathode constant current electrodeposition was carried out in a 50 ml electrolytic cell using a two - electrode system, where the cathode was the polyhedral CeO₂ prepared in step (1), and the electrolyte was a solution containing metal Pd ions; the working temperature was 25 °C, the weight ratio of metal Pd to polyhedral CeO₂ was 0.1:100, and then a second calcination was carried out at a temperature of 400 °C for 4 h.

[0155] Example 14

[0156] (1) 5.208 g of Ce(NO₃)₃·6H₂O was mixed with 60 mL of deionized water to form a Ce(NO₃)₃ solution, then 1.5 g of polyvinylpyrrolidone was added and stirred for 20 min, then 12 mL of 85% by mass N₂H₄·H₂O was added and stirred for 15 min, and then the mixed solution was placed in a 250 mL stainless - steel autoclave with a polytetrafluoroethylene lining at 180 °C for crystallization for 12 h. Then, solid - liquid separation was carried out, and the solid intermediate material was washed with deionized water and absolute ethanol, then dried in an oven at 80 °C for 8 h, and finally calcined in a tube furnace at 400 °C for 4 h to finally obtain polyhedral CeO₂;

[0157] The polyhedral CeO2 was impregnated into an aqueous solution of Zn(NO3)2, then dried at 120 °C for 10 h, and finally subjected to a first calcination in a tube furnace at a temperature of 400 °C for 4 h. Among them, the weight ratio of Zn(NO3)2 (calculated as metal) to the amount of polyhedral CeO2 used was 10:100;

[0158] (2) A cathode constant current electrodeposition was carried out in a 50 ml electrolytic cell using a two-electrode system. The cathode was the polyhedral CeO2 prepared in step (1), and the electrolyte was a solution containing metal Pd ions; the working temperature was 25 °C, and the weight ratio of metal Pd to the amount of polyhedral CeO2 used was 0.1:100. Then, a second calcination was carried out at a temperature of 400 °C for 4 h.

[0159] Example 15

[0160] (1) 5.208 g of Ce(NO3)3·6H2O was mixed with 60 mL of deionized water to form a Ce(NO3)3 solution, then 1.5 g of polyvinylpyrrolidone was added, and the mixture was stirred for 20 min. Then, 12 mL of N2H4·H2O with a mass concentration of 85% was added and stirred for 15 min. Then, the mixed solution was placed in a 250 mL stainless steel autoclave with a polytetrafluoroethylene lining at 180 °C for crystallization for 12 h. Then, solid-liquid separation was carried out, and the solid-phase intermediate material was washed with deionized water and absolute ethanol, and then dried in an oven at 80 °C for 8 h. Finally, it was calcined in a tube furnace at 400 °C for 4 h to finally obtain polyhedral CeO2;

[0161] The polyhedral CeO2 was impregnated into an aqueous solution of NaNO3, then dried at 120 °C for 10 h, and finally subjected to a first calcination in a tube furnace at a temperature of 400 °C for 4 h. Among them, the weight ratio of NaNO3 (calculated as metal) to the amount of polyhedral CeO2 used was 10:100;

[0162] (2) A cathode constant current electrodeposition was carried out in a 50 ml electrolytic cell using a two-electrode system. The cathode was the polyhedral CeO2 prepared in step (1), and the electrolyte was a solution containing metal Pd ions; the working temperature was 25 °C, and the weight ratio of metal Pd to the amount of polyhedral CeO2 used was 0.1:100. Then, a second calcination was carried out at a temperature of 400 °C for 4 h.

[0163] Example 16

[0164] (1) Mix 5.208 g of Ce(NO3)3·6H2O with 60 mL of deionized water to form a Ce(NO3)3 solution. Then add 1.5 g of polyvinylpyrrolidone and stir for 20 min. Next, add 12 mL of N2H4·H2O with a mass concentration of 85% and stir for 15 min. Then place the mixed solution in a 250 mL stainless steel autoclave with a polytetrafluoroethylene lining at 180 °C for crystallization for 12 h. Then perform solid-liquid separation, wash the solid intermediate material with deionized water and absolute ethanol, then dry it in an oven at 80 °C for 8 h, and finally calcine it in a tube furnace at 400 °C for 4 h to finally obtain polyhedral CeO2;

[0165] Immerse the polyhedral CeO2 into an aqueous KNO3 solution, then dry it at 120 °C for 10 h, and finally perform the first calcination in a tube furnace at a temperature of 400 °C for 4 h, where the weight ratio of KNO3 (calculated as metal) to the amount of polyhedral CeO2 used is 10:100;

[0166] (2) Use a two-electrode system to perform cathodic constant current electrodeposition in a 50 ml electrolytic cell, where the cathode is the polyhedral CeO2 prepared in step (1), and the electrolyte is a solution containing metal Pd ions; the working temperature is 25 °C, and the weight ratio of metal Pd to the amount of polyhedral CeO2 used is 0.1:100. Then perform the second calcination at a temperature of 400 °C for 4 h.

[0167] Comparative Example 1

[0168] (1) Mix 3.472 g of Ce(NO3)3·6H2O with 20 mL of deionized water to form a Ce(NO3)3 solution. Mix 38.4 g of NaOH with 140 mL of deionized water to form an NaOH solution. Mix the Ce(NO3)3 solution and the NaOH solution and stir for 0.5 h. Then place the mixed solution in a 250 mL stainless steel autoclave with a polytetrafluoroethylene lining at 100 °C for crystallization for 24 h. Then perform solid-liquid separation, wash the solid intermediate material with deionized water and absolute ethanol, then dry it in an oven at 80 °C for 8 h, and finally calcine it in a tube furnace at 400 °C for 4 h to finally obtain rod-shaped CeO2;

[0169] (2) Use a two-electrode system to perform cathodic constant current electrodeposition in a 50 ml electrolytic cell, where the cathode is the rod-shaped CeO2 prepared in step (1), and the electrolyte is a solution containing metal Pd ions; the working temperature is 25 °C, and the weight ratio of metal Pd to the amount of rod-shaped CeO2 used is 0.1:100. Then perform the second calcination at a temperature of 400 °C for 4 h.

[0170] Comparative Example 2

[0171] (1) Mix 3.472 g of Ce(NO3)3·6H2O with 20 mL of deionized water to form a Ce(NO3)3 solution. Mix 38.4 g of NaOH with 140 mL of deionized water to form an NaOH solution. Mix the Ce(NO3)3 solution and the NaOH solution and stir for 0.5 h. Then place the mixed solution in a 250 mL stainless steel autoclave with a polytetrafluoroethylene lining at 180 °C for crystallization for 24 h. Then perform solid-liquid separation, wash the solid intermediate material with deionized water and absolute ethanol, then dry it in an oven at 80 °C for 8 h, and finally calcine it in a tube furnace at 400 °C for 4 h to finally obtain cubic CeO2;

[0172] (2) Use a two-electrode system to perform cathodic constant current electrodeposition in a 50 ml electrolytic cell, where the cathode is the cubic CeO2 prepared in step (1), and the electrolyte is a solution containing metal Pd ions; the working temperature is 25 °C, and the weight ratio of the amount of metal Pd to cubic CeO2 is 0.1:100. Then perform a second calcination, and the calcination temperature is 400 °C and the time is 4 h.

[0173] Comparative Example 3

[0174] (1) Mix 1.716 g of Ce(NO3)3·6H2O with 20 mL of deionized water to form a Ce(NO3)3 solution. Mix 0.015 g of Na3PO4 with 140 mL of deionized water to form an Na3PO4 solution. Mix the Ce(NO3)3 solution and the Na3PO4 solution and stir for 0.5 h. Then place the mixed solution in a 250 mL stainless steel autoclave with a polytetrafluoroethylene lining at 170 °C for crystallization for 10 h. Then perform solid-liquid separation, wash the solid intermediate material with deionized water and absolute ethanol, then dry it in an oven at 80 °C for 8 h, and finally calcine it in a tube furnace at 400 °C for 4 h to finally obtain octahedral CeO2;

[0175] (2) Use a two-electrode system to perform cathodic constant current electrodeposition in a 50 ml electrolytic cell, where the cathode is the octahedral CeO2 prepared in step (1), and the electrolyte is a solution containing metal Pd ions; the working temperature is 25 °C, and the weight ratio of the amount of metal Pd to octahedral CeO2 is 0.1:100. Then perform a second calcination, and the calcination temperature is 400 °C and the time is 4 h.

[0176] Comparative Example 4

[0177] (1) Mix 5.208 g of Ce(NO3)3·6H2O with 60 mL of deionized water to form a Ce(NO3)3 solution. Then add 1.5 g of polyvinylpyrrolidone and stir for 20 min. Next, add 12 mL of N2H4·H2O with a mass concentration of 85% and stir for 15 min. Then place the mixed solution in a 250 mL stainless steel autoclave with a polytetrafluoroethylene lining at 180 °C for crystallization for 12 h. Then perform solid-liquid separation, wash the solid intermediate material with deionized water and absolute ethanol, then dry it in an oven at 80 °C for 8 h, and finally calcine it in a tube furnace at 400 °C for 4 h to finally obtain polyhedral CeO2;

[0178] (2) Use a two-electrode system to perform cathodic constant current electrodeposition in a 50 ml electrolytic cell, where the cathode is the polyhedral CeO2 prepared in step (1), and the electrolyte is a solution containing metal Pd ions; the working temperature is 25 °C, and the weight ratio of metal Pd to the amount of polyhedral CeO2 used is 0.1:100. Then perform a second calcination, and the calcination temperature is 400 °C and the time is 4 h.

[0179] Comparative Example 5

[0180] Carry out the implementation according to the method of Example 1, the difference is that the same weight of metal Ag is used to replace metal Pd in step (2).

[0181] Comparative Example 6

[0182] Carry out the implementation according to the method of Example 5, the difference is that the same weight of metal Ag is used to replace metal Pd in step (2).

[0183] Comparative Example 7

[0184] Carry out the implementation according to the method of Example 9, the difference is that the same weight of metal Fe is used to replace metal Pd in step (2).

[0185] Comparative Example 8

[0186] Carry out the implementation according to the method of Example 13, the difference is that the same weight of metal Fe is used to replace metal Pd in step (2).

[0187] Test Example

[0188] Perform catalytic activity tests on the samples prepared in the examples and comparative examples. The test method is as follows: Load the samples into a fixed-bed reactor, and pass the feed gas into the fixed-bed reactor to contact the samples. Among them, the feed gas consists of 99.25 vol% of ethylene, 0.25 vol% of oxygen, and 0.5 vol% of hydrogen. The contact conditions are: the space velocity is 3000 h -1, the pressure is 0.25 MPa, the temperature is 120 °C, and the deoxidation rate is calculated according to the final oxygen content in the raw gas. The test results are shown in Table 1;

[0189] Table 1

[0190]

[0191]

[0192] It can be seen from the results in Table 1 that the olefin deoxidation catalyst containing CeO2 according to the present invention has good catalytic activity. The olefin deoxidation catalyst containing CeO2 has high catalytic activity and can deeply deoxidize the olefin raw gas with a low oxygen content. The highest deoxidation rate can reach 99.8%, and it has good application prospects in olefin deoxidation.

[0193] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. An olefin deoxidation catalyst containing CeO2, characterized in that, The olefin deoxidation catalyst containing CeO2 includes a support and an active component supported on the support; The support contains CeO2 and a promoter, the promoter is selected from one or more of Mn oxide, Zn oxide, Na oxide and K oxide, and the active component is Pd oxide.

2. The olefin deoxidation catalyst containing CeO2 according to claim 1, wherein The weight ratio of Pd oxide to CeO2 is 0.1-0.5:100, wherein Pd oxide is calculated as metal; Preferably, the weight ratio of the promoter to CeO2 is 0.1-20:100, wherein the promoter is calculated as metal.

3. The olefin deoxygenation catalyst containing CeO2 according to claim 1 or 2, characterized in that, The CeO2 is rod-shaped CeO2, cubic CeO2, octahedral CeO2 or polyhedral CeO2.

4. A method for preparing an olefin deoxidation catalyst containing CeO2, characterized in that, The method includes the following steps: (1) Mix CeO2 and a promoter precursor solution, and then perform a first calcination; (2) Load metal Pd onto the material obtained in step (1), and then perform a second calcination; The promoter precursor is selected from one or more of manganese salts, zinc salts, sodium salts and potassium salts.

5. The method according to claim 4, characterized in that The CeO2 is rod-shaped CeO2, cubic CeO2, octahedral CeO2 or polyhedral CeO2.

6. The method according to claim 5, characterized in that, The preparation method of the rod-shaped CeO2 includes: mixing a Ce salt aqueous solution and sodium hydroxide, then performing crystallization, and then performing calcination; The conditions of the crystallization include: temperature is 60-150 °C, time is 10-50 h; The conditions of the calcination include: temperature is 300-600 °C, time is 2-8 h.

7. The method according to claim 5, characterized in that, The preparation method of the cubic CeO2 includes: mixing a Ce salt aqueous solution and sodium hydroxide, then performing crystallization, and then performing calcination; The conditions of the crystallization include: temperature is 160-300 °C, time is 10-50 h; The conditions of the calcination include: temperature is 300-600 °C, time is 2-8 h.

8. The method according to claim 5, characterized in that, The preparation method of the octahedral CeO2 includes: mixing a Ce salt aqueous solution and Na3PO4, then performing crystallization, and then performing calcination; The conditions of the crystallization include: temperature is 100-300 °C, time is 6-30 h; The conditions of the calcination include: temperature is 300-600 °C, time is 2-8 h.

9. The method according to claim 5, wherein The preparation method of the polyhedral CeO2 includes: mixing a Ce salt aqueous solution, polyvinylpyrrolidone and hydrazine hydrate, then performing crystallization, and then performing calcination; The conditions of the crystallization include: temperature is 80-200 °C, time is 10-30 h; The conditions of the calcination include: temperature is 300-600 °C, time is 2-8 h.

10. The method according to any one of claims 4-9, characterized in that, In step (1), the weight ratio of the promoter precursor to the amount of CeO2 used is 0.1-20:100, wherein the promoter precursor is calculated as metal; Preferably, the conditions of the first calcination include: temperature is 350-500 °C, time is 3-6 h.

11. The method according to any one of claims 4-10, characterized in that, In step (2), the weight ratio of metal Pd to the amount of CeO2 used is 0.1-0.5:100; Preferably, in step (2), the loading method is selected from impregnation, ion sputtering or electrochemical deposition; Preferably, in step (2), the conditions of the second calcination include: temperature is 350-500 °C, time is 3-6 h.

12. An olefin deoxidation catalyst containing CeO₂ prepared by the method according to any one of claims 4 - 11.

13. Use of the olefin deoxidation catalyst containing CeO₂ according to any one of claims 1 - 3 and 12 in an olefin deoxidation reaction.

14. A method for olefin deoxygenation reaction, characterized in that, Contacting a feed gas with the catalyst; The feed gas contains olefins, oxygen and hydrogen; The catalyst is the olefin deoxidation catalyst containing CeO₂ according to any one of claims 1 - 3 and 12.

15. The method according to claim 14, characterized in that, The content of oxygen in the feed gas is ≤ 0.25% by volume, and the volume ratio of hydrogen to oxygen is ≤ 4.

16. The method according to claim 14 or 15, characterized in that, The conditions for the contact include: the space velocity is 2000 - 5000 h -1 , the pressure is 0.1 - 0.4 MPa, and the temperature is 100 - 200 °C.

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