Process for the preparation of platinum / spherical ceria catalysts for the dehydrogenation of methylcyclohexane

Abstract

This invention discloses a method for preparing a platinum / spherical cerium dioxide catalyst for the dehydrogenation of methylcyclohexane, specifically comprising the following steps: Step 1, preparing spherical CeO2; Step 2, preparing Pt / spherical CeO2 based on the product obtained in Step 1; Step 3, preparing a three-dimensional Pt / spherical CeO2 catalyst based on the product obtained in Step 2. The catalyst prepared by the method of this invention can improve the dehydrogenation conversion rate of liquid hydrogen storage.

Description

Technical Field

[0001] This invention belongs to the field of hydrogen energy utilization technology and relates to a method for preparing a platinum / spherical cerium dioxide catalyst for the dehydrogenation of methylcyclohexane. Background Technology

[0002] The combustion of fossil fuels is currently the world's primary energy source, but it also brings problems such as energy depletion and environmental degradation. Developing new energy industries has become crucial. Hydrogen energy boasts high-quality energy density; 1 kg of hydrogen has a calorific value of 34,000 kcal, three times that of gasoline, and is environmentally friendly and non-toxic. Its sources are also very diverse. Currently, hydrogen is widely produced through water electrolysis, but storage and transportation are difficult. Liquid hydrogen storage is an emerging technology to solve this problem. Methylcyclohexane is the most promising liquid organic storage compound, and the widespread application of efficient and stable dehydrogenation catalysts is of great significance for the safe storage and transportation of hydrogen energy. Summary of the Invention

[0003] The purpose of this invention is to provide a method for preparing a platinum / spherical cerium dioxide catalyst for the dehydrogenation of methylcyclohexane. The catalyst prepared by this method can improve the dehydrogenation conversion rate of liquid hydrogen storage.

[0004] The technical solution adopted in this invention is a method for preparing a platinum / spherical cerium dioxide catalyst for the dehydrogenation of methylcyclohexane, which specifically includes the following steps:

[0005] Step 1: Prepare spherical CeO2;

[0006] Step 2: Prepare Pt / spherical CeO2 based on the product obtained in Step 1;

[0007] Step 3: Prepare a three-dimensional Pt / spherical CeO2 catalyst based on the product obtained in Step 2.

[0008] The invention is further characterized by:

[0009] The specific process of step 1 is as follows: Take 0.5g-2g of cerium nitrate, add 0.2g-0.6g of PVP, then pour in 2mL-5mL of deionized water and 20mL-40mL of ethylene glycol, stir for 20min-30min, transfer the resulting mixture into a reaction vessel, place it in a muffle furnace at 120℃-160℃ for hydrothermal reaction for 6h-8h, cool the reaction vessel to room temperature, open it and pour out the suspension, centrifuge it and wash it 3-5 times with deionized water and ethanol respectively, and then put it in an oven at 60℃-80℃ for 10h-12h to obtain spherical CeO2.

[0010] The specific process of step 2 is as follows:

[0011] Step 2.1: Disperse 0.5g-1g of spherical CeO2 in 15mL-30mL of deionized water, add 25mg-50mg of platinum nitrate, and sonicate for 0.5h-1h to obtain the catalyst precursor;

[0012] Step 2.2: Prepare 30mL-50mL of deionized water and add it to 0.1g-0.5g of sodium borohydride to obtain a sodium borohydride solution. Add the sodium borohydride solution dropwise into the catalyst precursor, let it stand for 6h-8h, centrifuge, wash it with deionized water 3-5 times, and dry it in an oven at 60℃-80℃ for 10h-12h to obtain the Pt / spherical CeO2 catalyst.

[0013] The specific process of step 3 is as follows:

[0014] Take 0.1g-0.5g of silicon carbide and 0.1g-0.5g of Pt / spherical CeO2 catalyst, mix them and put them into a ball mill. Ball mill for 20min-30min, sieve through a 100-120 mesh sieve, add 10mL-15mL of deionized water to make a slurry, take 5g-10g of polyurethane filter cotton, pour the slurry onto it, put it into a vacuum drying oven, dry at 80℃-105℃ for 6h-8h, then put it into a muffle furnace, raise the temperature to 900℃-1000℃ at a heating rate of 5℃ / min-10℃ / min, then raise the temperature to 1100℃-1200℃ at a heating rate of 2℃ / min-5℃ / min, hold for 30min-60min, and after calcination, obtain a three-dimensional Pt / spherical CeO2 catalyst.

[0015] The dehydrogenation process of Pt / spherical CeO2 catalyst is as follows: 0.2g-0.5g of three-dimensional Pt / spherical CeO2 catalyst is placed in the catalyst stationary, N2 is introduced, the pressure is adjusted to 0.2Mpa-0.4Mpa, the temperature is raised to 350℃-400℃, the gas flow rate is adjusted to 10mL / min-30mL / min, and the methylcyclohexane injection rate is 0.03mL / min-0.12mL / min.

[0016] The beneficial effects of this invention are as follows: It utilizes PVP to prepare spherical CeO2, increasing the specific surface area of ​​the support; introduces platinum as the catalytic active center; uses polyurethane filter cotton as the substrate; coats it with silicon carbide and Pt / spherical CeO2 catalyst; and then performs high-temperature sintering and foaming molding. This transforms the powdered catalyst into a three-dimensional structure catalyst, increasing the catalytic contact area, improving dispersion, and achieving a methylcyclohexane dehydrogenation conversion rate of over 90%. Attached Figure Description

[0017] Figure 1 This is a three-dimensional SEM image of Pt / spherical CeO2 prepared in Example 1 of the method for preparing platinum / spherical cerium dioxide catalyst for dehydrogenation of methylcyclohexane according to the present invention;

[0018] Figure 2 This is a macroscopic morphology diagram of three-dimensional Pt / spherical CeO2 prepared in Example 1 of the method for preparing platinum / spherical cerium dioxide catalyst for dehydrogenation of methylcyclohexane according to the present invention;

[0019] Figure 3 This is a test graph showing the catalytic performance of the three-dimensional Pt / spherical CeO2 catalyst prepared in Example 1 of the preparation method of the platinum / spherical cerium dioxide catalyst for the dehydrogenation of methylcyclohexane according to the present invention for the dehydrogenation of methylcyclohexane. Detailed Implementation

[0020] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0021] The present invention provides a method for preparing a platinum / spherical cerium dioxide catalyst for the dehydrogenation of methylcyclohexane, which specifically includes the following steps:

[0022] Step 1, the preparation of spherical CeO2, specifically involves:

[0023] Take 0.5-2 g of cerium nitrate, add 0.2-0.6 g of PVP, pour in 2-5 mL of deionized water and 20-40 mL of ethylene glycol, stir vigorously for 20-30 min, transfer the resulting mixture to a reaction vessel, and place it in a muffle furnace at 120℃-160℃ for hydrothermal reaction for 6-8 h. After the reaction vessel cools to room temperature, open it, pour out the suspension, centrifuge, wash 3-5 times with deionized water and ethanol, and then dry it in an oven at 60-80℃ for 10-12 h to obtain spherical CeO2 support.

[0024] Step 2, the preparation of Pt / spherical CeO2, specifically involves:

[0025] Disperse 0.5-1 g of spherical CeO2 in 15-30 mL of deionized water, add 25-50 mg of platinum nitrate, and sonicate for 0.5-1 h to obtain the catalyst precursor. Prepare 30-50 mL of deionized water, add 0.1-0.5 g of sodium borohydride, and slowly add it dropwise to the catalyst precursor. Let stand for 6-8 h, centrifuge, wash 3-5 times with deionized water, and dry in an oven at 60-80℃ for 10-12 h to obtain the Pt / spherical CeO2 catalyst.

[0026] Step 3, the preparation of the three-dimensional Pt / spherical CeO2 catalyst, specifically involves:

[0027] Take 0.1-0.5g of silicon carbide and 0.1-0.5g of Pt / spherical CeO2 catalyst, mix them and put them into a ball mill. Ball mill for 20-30min, sieve through a 100-120 mesh sieve, add 10-15mL of deionized water to make a slurry, take 5-10g of polyurethane filter cotton, pour the slurry onto it, and put it into a vacuum drying oven to dry at 80-105℃ for 6-8h. Then put it into a muffle furnace and heat it to 900-1000℃ at a heating rate of 5-10℃ / min, then heat it to 1100-1200℃ at a heating rate of 2-5℃ / min, hold it for 30-60min, and obtain a three-dimensional Pt / spherical CeO2 catalyst after calcination.

[0028] The catalytic performance of three-dimensional Pt / spherical CeO2 catalyst for the dehydrogenation of methylcyclohexane

[0029] Place 0.2-0.5g of three-dimensional Pt / spherical CeO2 catalyst into the catalytic fixation chamber, introduce N2, adjust the pressure to 0.2-0.4Mpa, raise the temperature to 350-400℃, adjust the gas flow rate to 10-30mL / min, and the methylcyclohexane injection rate to 0.03-0.12mL / min.

[0030] Example 1

[0031] Step 1: Take 1g of cerium nitrate, add 0.4g of PVP, pour in 2mL of deionized water and 30mL of ethylene glycol, stir vigorously for 20min, transfer the resulting mixture to a reaction vessel, and place it in a muffle furnace at 160℃ for hydrothermal reaction for 8h. After the reaction vessel cools to room temperature, open it, pour out the suspension, centrifuge, wash three times with deionized water and ethanol, and then dry it in an oven at 60℃ for 12h to obtain spherical CeO2 support.

[0032] Step 2: Disperse 0.5g of spherical CeO2 in 15mL of deionized water, add 28mg of platinum nitrate, and sonicate for 1h to obtain the catalyst precursor. Prepare 30mL of deionized water, add 0.3g of sodium borohydride, and slowly add it dropwise to the catalyst precursor. Let stand for 8h, centrifuge, wash three times with deionized water, and dry in an oven at 60℃ for 12h to obtain the Pt / spherical CeO2 catalyst.

[0033] Step 3: Take 0.3g of silicon carbide and 0.2g of Pt / spherical CeO2 catalyst, mix them and put them into a ball mill, ball mill for 20min, sieve through a 100-mesh sieve, add 10mL of deionized water to make a slurry, take 7.5g of polyurethane filter cotton, pour the slurry onto it, put it into a vacuum drying oven, and dry at 105℃ for 8h. Then put it into a muffle furnace, raise the temperature to 900℃ at a heating rate of 10℃ / min, then raise the temperature to 1100℃ at a heating rate of 2℃ / min, hold for 30min, and obtain a three-dimensional Pt / spherical CeO2 catalyst after calcination.

[0034] The catalytic performance of three-dimensional Pt / spherical CeO2 catalyst for the dehydrogenation of methylcyclohexane

[0035] 0.3g of silicon carbide three-dimensional foamed Pt / spherical CeO2 catalyst was placed in the catalytic fixation chamber, N2 was introduced, the pressure was adjusted to 0.3 MPa, the temperature was raised to 370℃, the gas flow rate was adjusted to 20 mL / min, and the methylcyclohexane injection rate was 0.05 mL / min.

[0036] Comparative Example 1 (In experimental step 1, PVP was not added, deionized water was used as the solvent, and hydrothermal treatment was used to obtain a cerium dioxide support with no special morphology and poor catalytic performance)

[0037] Step 1: Take 1g of cerium nitrate, pour it into 32mL of deionized water, stir vigorously for 20min, transfer the resulting mixture into a reaction vessel, and place it in a muffle furnace at 160℃ for hydrothermal reaction for 8h. After the reaction vessel cools to room temperature, open it and pour out the suspension. After centrifugation, wash it three times with deionized water and ethanol, and then place it in an oven at 60℃ for drying for 12h to obtain the CeO2 support.

[0038] Step 2: Disperse 0.5g CeO2 in 15mL deionized water, add 28mg platinum nitrate, and sonicate for 1h to obtain the catalyst precursor. Prepare 30mL deionized water, add 0.3g sodium borohydride, and slowly add it dropwise to the catalyst precursor. Let stand for 8h, centrifuge, wash three times with deionized water, and dry in an oven at 60℃ for 12h to obtain the Pt / CeO2 catalyst.

[0039] Step 3: Take 0.3g of silicon carbide and 0.2g of Pt / CeO2 catalyst, mix them and put them into a ball mill, ball mill for 20min, sieve through a 100-mesh sieve, add 10mL of deionized water to make a slurry, take 7.5g of polyurethane filter cotton, pour the slurry onto it, put it into a vacuum drying oven, and dry at 105℃ for 8h. Then put it into a muffle furnace, raise the temperature to 900℃ at a heating rate of 10℃ / min, then raise the temperature to 1100℃ at a heating rate of 2℃ / min, hold for 30min, and obtain the three-dimensional Pt / CeO2 catalyst after calcination.

[0040] 0.3 g of three-dimensional Pt / CeO2 catalyst was placed in the catalytic fixation chamber, N2 was introduced, the pressure was adjusted to 0.3 MPa, the temperature was raised to 370 °C, the gas flow rate was adjusted to 20 mL / min, and the methylcyclohexane injection rate was 0.05 mL / min.

[0041] Comparative Example 2 (In experimental step 3, 0.1g of silicon carbide was taken; the foaming did not form a solid shape, and the catalytic performance was poor)

[0042] Step 1: Take 1g of cerium nitrate, add 0.4g of PVP, pour in 2mL of deionized water and 30mL of ethylene glycol, stir vigorously for 20min, transfer the resulting mixture to a reaction vessel, and place it in a muffle furnace at 160℃ for hydrothermal reaction for 8h. After the reaction vessel cools to room temperature, open it, pour out the suspension, centrifuge, wash three times with deionized water and ethanol, and then dry it in an oven at 60℃ for 12h to obtain spherical CeO2 support.

[0043] Step 2: Disperse 0.5g of spherical CeO2 in 15mL of deionized water, add 28mg of platinum nitrate, and sonicate for 1h to obtain the catalyst precursor. Prepare 30mL of deionized water, add 0.3g of sodium borohydride, and slowly add it dropwise to the catalyst precursor. Let stand for 8h, centrifuge, wash three times with deionized water, and dry in an oven at 60℃ for 12h to obtain the Pt / spherical CeO2 catalyst.

[0044] Step 3: Take 0.1g of silicon carbide and 0.2g of Pt / spherical CeO2 catalyst, mix them and put them into a ball mill, ball mill for 20min, sieve through a 100-mesh sieve, add 10mL of deionized water to make a slurry, take 7.5g of polyurethane filter cotton, pour the slurry onto it, put it into a vacuum drying oven, and dry at 105℃ for 8h. Then put it into a muffle furnace, raise the temperature to 900℃ at a heating rate of 10℃ / min, then raise the temperature to 1100℃ at a heating rate of 2℃ / min, hold for 30min, and after calcination, obtain the three-dimensional Pt / spherical CeO2 catalyst.

[0045] 0.3 g of three-dimensional Pt / spherical CeO2 catalyst was placed in the catalytic fixation chamber, N2 was introduced, the pressure was adjusted to 0.3 MPa, the temperature was raised to 370 °C, the gas flow rate was adjusted to 20 mL / min, and the methylcyclohexane injection rate was 0.05 mL / min.

[0046] Comparative Example 3 (In experimental step 3, the heating rate was changed to 5℃ / min to 900℃, resulting in poor catalytic effect)

[0047] Step 1: Take 1g of cerium nitrate, add 0.4g of PVP, pour in 2mL of deionized water and 30mL of ethylene glycol, stir vigorously for 20min, transfer the resulting mixture to a reaction vessel, and place it in a muffle furnace at 160℃ for hydrothermal reaction for 8h. After the reaction vessel cools to room temperature, open it, pour out the suspension, centrifuge, wash three times with deionized water and ethanol, and then dry it in an oven at 60℃ for 12h to obtain spherical CeO2 support.

[0048] Step 2: Disperse 0.5g of spherical CeO2 in 15mL of deionized water, add 28mg of platinum nitrate, and sonicate for 1h to obtain the catalyst precursor. Prepare 30mL of deionized water, add 0.3g of sodium borohydride, and slowly add it dropwise to the catalyst precursor. Let stand for 8h, centrifuge, wash three times with deionized water, and dry in an oven at 60℃ for 12h to obtain the Pt / spherical CeO2 catalyst.

[0049] Step 3: Take 0.1g of silicon carbide and 0.2g of Pt / spherical CeO2 catalyst, mix them and put them into a ball mill, ball mill for 20min, sieve through a 100-mesh sieve, add 10mL of deionized water to make a slurry, take 7.5g of polyurethane filter cotton, pour the slurry onto it, put it into a vacuum drying oven, and dry at 105℃ for 8h. Then put it into a muffle furnace, raise the temperature to 900℃ at a heating rate of 5℃ / min, then raise the temperature to 1100℃ at a heating rate of 2℃ / min, hold for 30min, and after calcination, obtain the three-dimensional Pt / spherical CeO2 catalyst.

[0050] 0.3 g of three-dimensional Pt / spherical CeO2 catalyst was placed in the catalytic fixation chamber, N2 was introduced, the pressure was adjusted to 0.3 MPa, the temperature was raised to 370 °C, the gas flow rate was adjusted to 20 mL / min, and the methylcyclohexane injection rate was 0.05 mL / min.

[0051] Table 1 below compares the catalytic performance of the catalysts prepared in Example 1 with those in Comparative Examples 1 to 3 for catalyzing methylcyclohexane:

[0052] Table 1

[0053]

[0054]

[0055] like Figure 1 As shown, the three-dimensional framework is doped with spherical cerium dioxide, which has a large specific surface area, which is beneficial to improving catalytic activity and dispersing platinum particles.

[0056] like Figure 2 As shown, the three-dimensional structure can be applied to fixed-bed dehydrogenation reactions more effectively and conveniently, increasing the contact area with the reactant gases and improving catalytic utilization.

[0057] like Figure 3As shown in Table 1, the catalyst in Example 1 exhibits superior catalytic performance and strong stability compared to other comparative experiments. Comparative Example 1, lacking PVP to alter the morphology of cerium dioxide, has a smaller specific surface area, affecting platinum activity and resulting in poor conversion and stability. The foaming failure in Comparative Example 2 is likely due to insufficient silicon carbide addition, affecting the macroscopic three-dimensional framework and thus limiting the contact area with gas during the dehydrogenation reaction, thereby impacting conversion. In Comparative Example 3, the change in heating rate and excessive calcination time may have affected catalyst activity.

[0058] Example 2

[0059] Step 1: Take 0.5g of cerium nitrate, add 0.2g of PVP, pour in 3mL of deionized water and 20mL of ethylene glycol, stir vigorously for 25min, transfer the resulting mixture to a reaction vessel, and place it in a muffle furnace at 140℃ for hydrothermal reaction for 7h. After the reaction vessel cools to room temperature, open it and pour out the suspension. After centrifugation, wash it four times with deionized water and ethanol respectively, and then place it in an oven at 70℃ for 11h to obtain spherical CeO2 support.

[0060] Step 2: Disperse 0.8g of spherical CeO2 in 25mL of deionized water, add 25mg of platinum nitrate, and sonicate for 0.5h to obtain the catalyst precursor. Prepare 40mL of deionized water and add 0.1g of sodium borohydride. Slowly add the sodium borohydride solution dropwise to the catalyst precursor, let stand for 7h, centrifuge, wash 4 times with deionized water, and dry in an oven at 70℃ for 11h to obtain the Pt / spherical CeO2 catalyst.

[0061] Step 3: Take 0.1g of silicon carbide and 0.1g of Pt / spherical CeO2 catalyst, mix them and put them into a ball mill, ball mill for 25min, sieve through a 110-mesh sieve, add 12mL of deionized water to make a slurry, take 5g of polyurethane filter cotton, pour the slurry onto it, put it in a vacuum drying oven, and dry at 95℃ for 7h. Then put it into a muffle furnace, raise the temperature to 950℃ at a heating rate of 8℃ / min, then raise the temperature to 1150℃ at a heating rate of 4℃ / min, hold for 40min, and obtain the three-dimensional Pt / spherical CeO2 catalyst after calcination.

[0062] The catalytic performance of three-dimensional Pt / spherical CeO2 catalyst for the dehydrogenation of methylcyclohexane

[0063] 0.2g of silicon carbide three-dimensional foamed Pt / spherical CeO2 catalyst was placed in the catalytic fixation chamber, N2 was introduced, the pressure was adjusted to 0.2 MPa, the temperature was raised to 350℃, the gas flow rate was adjusted to 10 mL / min, and the methylcyclohexane injection rate was 0.03 mL / min.

[0064] Example 3

[0065] Step 1: Take 2g of cerium nitrate, add 0.6g of PVP, pour in 5mL of deionized water and 40mL of ethylene glycol, stir vigorously for 30min, transfer the resulting mixture to a reaction vessel, and place it in a muffle furnace at 120℃ for hydrothermal reaction for 6h. After the reaction vessel cools to room temperature, open it and pour out the suspension. After centrifugation, wash it 5 times each with deionized water and ethanol, and then dry it in an oven at 80℃ for 10h to obtain spherical CeO2 support.

[0066] Step 2: Disperse 1g of spherical CeO2 in 30mL of deionized water, add 50mg of platinum nitrate, and sonicate for 1h to obtain the catalyst precursor. Prepare 50mL of deionized water and add 0.5g of sodium borohydride. Slowly add the sodium borohydride solution dropwise to the catalyst precursor, let stand for 8h, centrifuge, wash 5 times with deionized water, and dry in an oven at 80℃ for 12h to obtain the Pt / spherical CeO2 catalyst.

[0067] Step 3: Take 0.5g of silicon carbide and 0.5g of Pt / spherical CeO2 catalyst, mix them and put them into a ball mill, ball mill for 30min, sieve through a 120-mesh sieve, add 15mL of deionized water to make a slurry, take 10g of polyurethane filter cotton, pour the slurry onto it, put it in a vacuum drying oven, and dry at 80℃ for 6h. Then put it into a muffle furnace, raise the temperature to 1000℃ at a heating rate of 5℃ / min, then raise the temperature to 1200℃ at a heating rate of 5℃ / min, hold for 60min, and after calcination, obtain the three-dimensional Pt / spherical CeO2 catalyst.

[0068] The catalytic performance of three-dimensional Pt / spherical CeO2 catalyst for the dehydrogenation of methylcyclohexane

[0069] 0.5g of silicon carbide three-dimensional foamed Pt / spherical CeO2 catalyst was placed in the catalytic fixation chamber, N2 was introduced, the pressure was adjusted to 0.4 MPa, the temperature was raised to 400℃, the gas flow rate was adjusted to 30 mL / min, and the methylcyclohexane injection rate was 0.12 mL / min.

Claims

1. A method for preparing a platinum / spherical cerium dioxide catalyst for the dehydrogenation of methylcyclohexane, characterized in that: Specifically, the steps include the following: Step 1, Preparation of spherical CeO2; The specific process of Step 1 is as follows: Take 0.5g-2g of cerium nitrate, add 0.2g-0.6g of PVP, then pour in 2mL-5mL of deionized water and 20mL-40mL of ethylene glycol, stir for 20min-30min, transfer the resulting mixture into a reaction vessel, place it in a muffle furnace at 120℃-160℃ for hydrothermal reaction for 6h-8h, cool the reaction vessel to room temperature, open and pour out the suspension, centrifuge, wash with deionized water and ethanol 3-5 times respectively, and then place it in an oven at 60℃-80℃ for 10h-12h to obtain spherical CeO2; Step 2: Prepare Pt / spherical CeO2 based on the product obtained in Step 1. The specific process of Step 2 is as follows: Step 2.1: Disperse 0.5g-1g of spherical CeO2 in 15mL-30mL of deionized water, add 25mg-50mg of platinum nitrate, and sonicate for 0.5h-1h to obtain the catalyst precursor; Step 2.2: Prepare 30mL-50mL of deionized water and add it to 0.1g-0.5g of sodium borohydride to obtain a sodium borohydride solution. Add the sodium borohydride solution dropwise into the catalyst precursor, let it stand for 6h-8h, centrifuge, wash with deionized water 3-5 times, and dry in an oven at 60℃-80℃ for 10h-12h to obtain the Pt / spherical CeO2 catalyst. Step 3: Prepare a three-dimensional Pt / spherical CeO2 catalyst based on the product obtained in Step 2. The specific process of Step 3 is as follows: Take 0.3g-0.5g of silicon carbide and 0.2g-0.5g of Pt / spherical CeO2 catalyst, mix them and put them into a ball mill. Ball mill for 20min-30min, sieve through a 100-120 mesh sieve, add 10mL-15mL of deionized water to make a slurry, take 7.5g-10g of polyurethane filter cotton, pour the slurry onto it, put it into a vacuum drying oven, dry at 80℃-105℃ for 6h-8h, then put it into a muffle furnace, raise the temperature to 900℃-1000℃ at a heating rate of 8~10℃ / min, then raise the temperature to 1100℃-1200℃ at a heating rate of 2℃ / min-5℃ / min, hold for 30min-60min, and after calcination, obtain a three-dimensional Pt / spherical CeO2 catalyst.

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