Preparation method of photothermal catalytic material with low noble metal content and its application

Abstract

The present invention discloses a method for preparing a photothermal catalytic material with a low noble metal content and its application. The preparation method comprises the following steps: dissolving a metal salt, ferric nitrate, and cerium nitrate in deionized water, adding the solution dropwise to a NaOH solution, mixing, and performing a hydrothermal treatment; collecting the precipitate by centrifugation, washing, vacuum drying, grinding, and calcining the powder at high temperature; and cooling the precipitate to obtain a catalyst powder material. The photothermal catalytic material prepared by the present invention can be used in the catalysis of mixed gas reactions. The catalyst material reduces the start-up temperature of the reverse water gas reaction by 125°C, increases the CO2 conversion rate by 8.5 times at 450°C, and exhibits a high CO generation rate (326mmol g) under light conditions. cat ‑1 h ‑1 ) and stability, and the precious metal (Ru) content used in this catalyst is extremely low, only 0.02% to 0.25%, which is much lower than the commonly used content of 1% to 5% in other catalysts, effectively reducing the cost of raw materials.

Description

Technical Field

[0001] The present invention belongs to the field of catalyst technology, and specifically relates to a method for preparing a photothermal catalytic material with low noble metal content and an application thereof. Background Art

[0002] The widespread use of fossil fuels has led to a series of problems, including the greenhouse effect and energy shortages caused by massive carbon dioxide emissions. The catalytic hydrogenation of carbon dioxide not only consumes CO2, thereby contributing to the achievement of carbon peak and carbon neutrality goals, but also effectively utilizes CO2, converting it and green hydrogen into high-value-added chemicals and fuels. Therefore, the hydrogenation of CO2 has dual significance for environmental protection and the conversion of carbon resources into energy.

[0003] The reverse water gas reaction (CO2+H2→CO+H2O) is an effective method for large-scale production of CO. CO is an important chemical raw material that can be synthesized into high-value carbon-based chemicals and fuels through commercial methods such as the Fischer-Tropsch process and methanol synthesis. However, for traditional thermal catalysis, in order to achieve a higher reverse water gas reaction rate and conversion rate, a temperature of more than 500°C is often required. Such high temperature will lead to a large amount of energy consumption, which violates the original intention of converting carbon resources into energy and negates the benefits of large-scale implementation of the RWGS reaction. Chinese patent CN114146710A discloses a surface-loaded Na + and / or K + Co3O4 nanomaterials are used to thermally catalyze the reverse water-gas reaction. However, the problem with the thermal catalytic technology used in this patent is that it utilizes the heat energy generated by burning fossil fuels (a process that emits a large amount of CO2), and then uses this heat to catalyze the reaction of CO2 to produce CO. This reaction is clearly uneconomical from an energy and economic perspective (using fossil energy to produce CO) and irrational in terms of carbon cycle (emitting a large amount of CO2 while also utilizing some of it).

[0004] Therefore, lowering the reaction temperature and achieving clean energy input (using clean light energy to achieve the reverse water-gas reaction) are the key to the current reaction. Photothermal catalysis, which uses clean light energy to generate heat on the catalyst surface to drive the catalytic reaction, can solve these problems. Summary of the Invention

[0005] Purpose of the invention: In response to the problems existing in the prior art, the present invention provides a method for preparing photothermal catalytic materials with low precious metal content, which can effectively reduce the reaction temperature and realize the reliable use of light, and effectively reduce the cost of the catalyst by utilizing the extremely low precious metal content, thereby solving the problems of high temperature and clean energy in the reverse water gas reaction.

[0006] The present invention also provides application of the prepared photothermal catalytic material in a reverse water-gas catalytic reaction.

[0007] Technical solution: In order to achieve the above-mentioned purpose, the present invention provides a method for preparing a photothermal catalytic material with low noble metal content, comprising the following steps:

[0008] S1. Dissolve the metal salt, ferric nitrate and cerium nitrate in deionized water, stir evenly and then add dropwise to the NaOH solution, mix and then perform hydrothermal treatment;

[0009] S2. Collect the precipitate by centrifugation, wash, vacuum dry, grind, calcine the powder at high temperature, and obtain the catalyst powder material after cooling.

[0010] Furthermore, the metal in the metal salt in step (1) is any one of Ru, Cu, Ni, Co, and Rh.

[0011] Preferably, the metal material in step (1) is Ru.

[0012] Furthermore, in step (1), the molar content ratio of the metal salt, ferric nitrate and cerium nitrate is 0.02% to 0.25%: 0.1 to 0.9: 0.9 to 0.1.

[0013] Preferably, the molar content ratio of the metal salt, ferric nitrate and cerium nitrate in step (1) is 0.25%:0.3:0.7.

[0014] Furthermore, the concentration of the NaOH solution in step (1) is 0.1 mol / L to 10 mol / L.

[0015] Furthermore, the hydrothermal treatment temperature in step (1) is 100° C. to 120° C., and the treatment time is 23 h to 25 h.

[0016] Furthermore, the temperature of the high-temperature calcination in step (2) is 440° C. to 460° C., and the calcination time is 3.5 h to 4 h.

[0017] Preferably, the specific preparation steps are as follows:

[0018] S1. Dissolve ruthenium chloride (RuCl3·nH2O), ferric nitrate (Fe(NO3)3·9H2O), and cerium nitrate (Ce(NO3)3·6H2O) in deionized water at a molar ratio of 0.25%:0.3:0.7, and stir until completely dissolved. This is referred to as solution A.

[0019] S2. Prepare a sodium hydroxide solution of a certain concentration, NaOH, which is referred to as solution B.

[0020] S3, adding solution A dropwise to solution B, stirring evenly, allowing the mixture to stand after being fully mixed; placing the mixed solution into an autoclave for hydrothermal treatment;

[0021] S4. After hydrothermal treatment, the precipitate was collected by centrifugation, washed several times with deionized water, dried under vacuum at room temperature, and ground into fine powder. The powder was calcined at high temperature in hydrogen and cooled naturally to room temperature to obtain powdered Ru. 0.25％ :Ce 0.7 Fe 0.3 O2 material.

[0022] Application of the photothermal catalytic material with low noble metal content prepared by the present invention in the reverse water gas catalytic reaction.

[0023] Preferably, the application process is:

[0024] a. Place the catalyst powder into the catalytic reactor and spread it into a thin circular layer;

[0025] b. Passing reaction gases CO2, H2, and Ar into the catalyst powder, and irradiating the catalyst with a 300W xenon lamp;

[0026] c. Data analysis was performed using a micro gas chromatograph equipped with a micro thermal conductivity detector.

[0027] Preferably, the application process is:

[0028] a. Place the catalyst powder into the catalytic reactor and spread it into a thin circular layer;

[0029] b. Passing reaction gases CO2, H2, and Ar into the catalyst powder and heating the catalyst;

[0030] c. Data analysis was performed using a micro gas chromatograph equipped with a micro thermal conductivity detector.

[0031] Furthermore, in step b, the volume ratio of CO2, H2, and Ar is any one of 1:4:95, 32:64:4, 48:48:4, and 64:32:4, and the heating or illumination time is 5 min to 12 h.

[0032] The reaction mechanism is: the catalyst dopes Ru and Fe into CeO2 to form Ru 0.25％ :Ce 0.7 Fe 0.3 O2 solid solution enhances the catalyst's absorption of light in the UV-visible-near infrared band and converts light into heat energy, thereby heating the catalyst. Under the action of light and heat and the reducing atmosphere provided by H2, the catalyst will form a large number of oxygen vacancies and generate H2O. CO2 is adsorbed by the oxygen vacancies and further breaks the CO bond, converting to CO. Ru formed with CeO2 as the matrix0.25％ :Ce 0.7 Fe 0.3 O2 is rich in oxygen vacancies under reducing conditions, which is conducive to the reaction. And the metal Ru promotes the dissociation of H2 and the formation of oxygen vacancies, thereby reducing the activation energy of the reverse water gas reaction and thus reducing the reaction temperature. And Ru 0.25％ :Ce 0.7 Fe 0.3 The O2 solid solution is stable during the reaction, which greatly extends the service life of the catalyst.

[0033] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages:

[0034] 1. Compared with the traditional undoped non-solid solution Fe-based materials (such as Fe3O4 mixed with CeO2), the catalyst material of the present invention reduces the opening temperature of the reverse water gas reaction by nearly 125℃ (from 325℃ to 200℃), and the CO2 conversion rate at 450℃ is increased by 8.5 times. It shows a high CO generation rate (326mmol gcat) under light conditions. -1 h -1 ) and stability. And the doping of Fe and Ru enhances the absorption of light and realizes the effective utilization of light;

[0035] 2. The precious metal (Ru) content of the catalyst used in the preparation method of the present invention is extremely low, only 0.02% to 0.25%, far lower than the commonly used content of 1% to 5% in catalysts, effectively reducing raw material costs. Furthermore, the preparation method adopted by the present invention has good reproducibility, can be prepared on a large scale, and is durable. It achieves a green reaction between industrial waste gas CO2 and green hydrogen (hydrogen produced by electrolysis of water from wind power, hydropower, and photovoltaic power generation), realizing the utilization of renewable energy and the valuable storage of carbon resources.

[0036] 3. The preparation method of the present invention adopts photothermal catalysis, which uses clean light energy to drive the reaction, rather than thermal catalysis that uses fossil energy to burn heat. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 The Ru prepared by the present invention 0.25％ :Ce 0.7 Fe 0.3 Schematic diagram of photothermal catalysis and temperature distribution of O2 catalyst;

[0038] Figure 2 The Ru prepared by the present invention 0.25％ :Ce 0.7 Fe 0.3 Scanning electron microscope image of O2 catalyst;

[0039] Figure 3 The Ru prepared by the present invention0.25％ :Ce 0.7 Fe 0.3 Transmission electron microscopy image of the O2 catalyst;

[0040] Figure 4 The Ru prepared by the present invention 0.25％ :Ce 0.7 Fe 0.3 X-ray diffraction pattern of O2 catalyst;

[0041] Figure 5 The Ru prepared by the present invention 0.25％ :Ce 0.7 Fe 0.3 UV-visible-near-infrared diffuse reflectance spectra of O2 catalyst and other comparison catalysts;

[0042] Figure 6 The Ru prepared by the present invention 0.25％ :Ce 0.7 Fe 0.3 Synchrotron radiation X-ray near-edge absorption spectroscopy of O2 catalysts;

[0043] Figure 7 The Ru prepared by the present invention 0.25％ :Ce 0.7 Fe 0.3 Thermal catalytic mobile phase performance diagram of O2 catalyst and other comparative catalysts;

[0044] Figure 8 The Ru with different Ru contents prepared by the present invention 0.25％ :Ce 0.7 Fe 0.3 Photothermal catalytic sequencing batch reaction performance diagram of O2 catalyst;

[0045] Figure 9 The Ru prepared by the present invention 0.25％ :Ce 0.7 Fe 0.3 Photothermal catalytic sequencing batch reaction performance diagram of O2 catalyst under different CO2 and H2 ratios;

[0046] Figure 10 The Ru prepared by the present invention 0.25％ :Ce 0.7 Fe 0.3 Photothermal catalytic mobile phase stability test diagram of O2 catalyst. DETAILED DESCRIPTION

[0047] The experimental methods described in the examples are conventional methods unless otherwise specified; the reagents and materials described are commercially available unless otherwise specified.

[0048] Ferric nitrate manufacturer: Aladdin; CAS number: 7782-61-8; item number: F100208-100g,

[0049] Cerium nitrate manufacturer: Aladdin; CAS number: 10294-41-4; item number: C105378-500g,

[0050] Ruthenium chloride manufacturer: Aladdin; CAS number: 20759-14-2; product number: R191989-250mg,

[0051] Copper nitrate manufacturer: Aladdin; CAS number: 13778-31-9; item number: C102130-100g,

[0052] Cobalt nitrate manufacturer: Aladdin; CAS number: 10026-22-9; item number: C112729-25g,

[0053] Nickel nitrate manufacturer: Aladdin; CAS number: 13478-00-7; item number: N108891-100g,

[0054] Rhodium chloride manufacturer: Macklin; CAS number: 10049-07-7; product number: R833344-10mg.

[0055] Example 1

[0056] A photothermal catalytic material with low noble metal content Ru 0.25％ :Ce 0.7 Fe 0.3 The preparation method of O2, the specific steps are as follows:

[0057] S1. Dissolve cerium nitrate Ce(NO3)3·6H2O (2.8 mmol), iron nitrate Fe(NO3)3·9H2O (1.2 mmol), and ruthenium chloride RuCl3·nH2O (0.01 mmol) in 10 ml of deionized water and stir until completely dissolved. This is referred to as solution A.

[0058] S2. Prepare 70 mL of 10 mol / L NaOH solution, referred to as solution B. Add solution A dropwise to solution B, mix, and allow to stand for 30 min. After standing, place the mixed solution in an autoclave and perform hydrothermal treatment at 120° C. for 24 h.

[0059] S3. After treatment, the precipitate was collected by centrifugation, washed with deionized water until the pH of the clarified liquid was neutral, dried under vacuum at room temperature, and ground into fine powder. The powder was calcined at 450 ° C for 4 h in a concentration of 5% hydrogen and 95% argon Ar, and naturally cooled to room temperature to obtain the powder material Ru. 0.25％ :Ce 0.7 Fe 0.3 O2;

[0060] The ruthenium chloride RuCl3·nH2O in step S1 was replaced by copper nitrate Cu(NO3)2·nH2O, cobalt nitrate Co(NO3)2·6H2O, nickel nitrate Ni(NO3)2·6H2O, and rhodium chloride RhCl3, respectively, and then the above steps S1, S2 and S3 were repeated unchanged to prepare the powder materials Cu 0.25％ :Ce 0.7 Fe 0.3 O2、Co 0.25％ :Ce 0.7 Fe 0.3 O2,Ni 0.25％ :Ce 0.7 Fe 0.3 O2、Rh 0.25％ :Ce 0.7 Fe 0.3 O2. Figure 2 It can be seen that 0.25％ :Ce 0.7 Fe 0.3 O2 materials are composed of nanorods and nanoparticles, with nanorods being the main component. Figure 3 As shown, Ru 0.25％ :Ce 0.7 Fe 0.3 The crystal surface distribution and lattice fringes of O2 powder materials show the crystal structure of nanorods; Figure 4 The material shown is (CeO2) 0.7 :(FeO x ) 0.3 :(RuO2) 0.25％ solid solution.

[0061] Example 2

[0062] Photothermal catalytic materials Ru:Ce with different precious metal Ru contents 0.7 Fe 0.3 The preparation method of O2 is as follows:

[0063] S1. Dissolve cerium nitrate Ce(NO3)3·6H2O (2.8 mmol), iron nitrate Fe(NO3)3·9H2O (1.2 mmol), and ruthenium chloride RuCl3·nH2O (0.01 mmol) in 10 ml of deionized water and stir until completely dissolved. This is referred to as solution A.

[0064] S2. Prepare 70 mL of 10 mol / L NaOH solution, referred to as solution B. Add solution A dropwise to solution B, mix, and allow to stand for 30 min. After standing, place the mixed solution in an autoclave and perform hydrothermal treatment at 120° C. for 24 h.

[0065] S3. After treatment, the precipitate was collected by centrifugation, washed with deionized water until the pH of the clarified liquid was neutral, dried under vacuum at room temperature, and ground into fine powder. The powder was calcined at 450 ° C for 4 h in a concentration of 5% hydrogen and 95% argon Ar, and naturally cooled to room temperature to obtain the material Ru. 0.25％ :Ce 0.7 Fe 0.3 O2;

[0066] The amount of ruthenium chloride RuCl3·nH2O in step S1 was changed to 8×10 -4 mmol, 0.2mmol and without adding ruthenium chloride RuCl3·nH2O. Then repeat the above steps S1, S2 and S3 unchanged to prepare Ru with a Ru:Fe:Ce element molar ratio of 0.02%:0.3:0.7 and 5%:0.3:0.7 respectively. 0.02％ :Ce 0.7 Fe 0.3 O2 and Ru 5％ :Ce 0.7 Fe 0.3 O2 and elemental Ce without Ru 0.7 Fe 0.3 O2 powder material.

[0067] The preparation method of CeO2 powder is as follows:

[0068] S1. Dissolve cerium nitrate Ce(NO3)3·6H2O (2.8 mmol) in 10 ml of deionized water and stir until completely dissolved. This solution is referred to as solution A.

[0069] S2. Prepare 70 mL of 10 mol / L NaOH solution, referred to as solution B. Add solution A dropwise to solution B, mix, and allow to stand for 30 min. After standing, place the mixed solution in an autoclave and perform hydrothermal treatment at 120° C. for 24 h.

[0070] S3. After treatment, the precipitate is collected by centrifugation, washed with deionized water until the clarified liquid Ph is neutral, dried under vacuum at room temperature, and ground into fine powder. The powder is calcined at 450°C for 4 hours in a 5% hydrogen and 95% argon atmosphere, and cooled naturally to room temperature to obtain the material CeO2.

[0071] The preparation method of 30% Fe3O4 / CeO2 as a comparative sample is as follows:

[0072] 0.4 mmol of commercial Fe3O4 and 2.8 mmol of CeO2 prepared by the above method were placed in an agate mortar and ground for 30 minutes to obtain a 30% Fe3O4 / CeO2 comparative sample.

[0073] like Figure 5 The Ru prepared in Example 1 is shown 0.25％ :Ce 0.7 Fe 0.3 O2 powder material and comparative powder material Ce prepared in Example 2 0.7 Fe 0.3 UV-visible near-infrared diffuse reflectance spectra (300-2500nm) of O2, 30% Fe3O4 / CeO2, and CeO2. As can be seen from the figure, CeO2 exhibits band gap absorption in the ultraviolet region, while Ce 0.7 Fe 0.3 O2 and Ru 0.25％ :Ce 0.7 Fe 0.3 O2 solid solution shows full spectrum absorption up to 2500nm, while the physically mixed 30% Fe3O4 / CeO2 material only shows obvious enhancement in the near infrared band. 0.25％ :Ce 0.7 Fe 0.3 The light absorption of O2 is significantly stronger than that of Ce without Ru. 0.7 Fe 0.3 O2.

[0074] Example 3

[0075] The following experiments are performed to understand Ru 0.25％ :Ce 0.7 Fe 0.3 The reverse water gas reaction performance of O2 materials and the performance difference with comparison materials.

[0076] This experiment tested the Ru prepared in Example 1. 0.25％ :Ce 0.7 Fe 0.3 O2、Cu 0.25％ :Ce 0.7 Fe 0.3 O2、Co 0.25％:Ce 0.7 Fe 0.3 O2,Ni 0.25％ :Ce 0.7 Fe 0.3 O2 material and the comparative material prepared in Example 2 (30% Fe3O4 / CeO2, Ce 0.7 Fe 0.3 The performance of the reverse water-gas reaction was investigated under conditions of thermal catalysis (CO2) and photothermal catalysis (pure light). The reaction gas ratios were: CO2:H2:Ar = 1:4:95, 32:64:4, 48:48:4, or 64:32:4.

[0077] This experiment is mainly divided into the following three categories:

[0078] 1. Thermocatalytic mobile phase test has the following steps:

[0079] a. Weigh 30% Fe3O4 / CeO2 and Ce prepared in Example 1 and Example 2, respectively. 0.7 Fe 0.3 O2、Ru 0.25％ :Ce 0.7 Fe 0.3 O2、Cu 0.25％ :Ce 0.7 Fe 0.3 O2、Co 0.25％ :Ce 0.7 Fe 0.3 O2,Ni 0.25％ :Ce 0.7 Fe 0.3 O2 and Rh 0.25％ :Ce 0.7 Fe 0.3 O2 catalyst powder (6 mg) was placed in the catalytic reactor and spread into a thin layer;

[0080] b. Under normal pressure, the reaction gas (CO2:H2:Ar=1:4:95) was introduced into the catalytic reactor, the temperature of the reactor was adjusted to 450℃, and the reaction gas flow rate was 30sccm (cm under standard conditions). 3 The catalyst was treated for 30 minutes for activation.

[0081] c. While maintaining the flow of the reaction gas, immediately begin testing after 30 minutes of activation, using a micro gas chromatograph equipped with a micro thermal conductivity detector for data detection and analysis.

[0082] like Figure 7 As shown, the 30% Fe3O4 / CeO2, Ce prepared in Examples 1 and 2 0.7 Fe 0.3 O2、Ru0.25％ :Ce 0.7 Fe 0.3 O2、Cu 0.25％ :Ce 0.7 Fe 0.3 O2、Co 0.25％ :Ce 0.7 Fe 0.3 O2, Ni 0.25％ :Ce 0.7 Fe 0.3 O2 and Rh 0.25％ :Ce 0.7 Fe 0.3 Thermal catalytic mobile phase performance diagram of O2 material, gas concentration is CO2:H2:Ar=1:4:95. Through comparative analysis, among the 7 catalysts, Ru 0.25％ :Ce 0.7 Fe 0.3 O2 materials have the most significant effect on reducing the temperature of the reverse water gas reaction and improving the CO2 conversion rate. Compared with traditional undoped non-solid solution Fe-based materials (such as CeO2 mixed Fe3O4 catalyst 30% Fe3O4 / CeO2), Ru 0.25％ :Ce 0.7 Fe 0.3 The O2 catalyst lowered the activation temperature of the reverse water gas reaction (CO2+H2=CO+H2O) by 125°C (from 325°C to 200°C), and increased the CO2 conversion rate by 8.5 times (from 4.7% to 39.8%) at 450°C. Similarly, the above effects can be achieved by continuous irradiation activation with a 300W xenon lamp.

[0083] 2. The mobile phase test for photothermal catalysis (pure light conditions) has the following steps:

[0084] a. Weigh the Ru prepared in Example 1 0.25％ :Ce 0.7 Fe 0.3 O2 catalyst powder (50 mg) was placed in a catalytic reactor equipped with a quartz window for observation and illumination and spread into a thin layer with a diameter of about 4 cm;

[0085] b. Under normal pressure, the reaction gas (CO2:H2:Ar=48:48:4) was introduced into the catalytic reactor and continuously irradiated with a 300W xenon lamp. The reaction gas flow rate was 30sccm (cm under standard conditions). 3 The catalyst was treated for 30 minutes for activation.

[0086] c. While maintaining the flow of the reaction gas, immediately begin testing after 30 minutes of activation, using a micro gas chromatograph equipped with a micro thermal conductivity detector for data detection and analysis.

[0087] like Figure 1 The representative material Ru prepared by the present invention is shown. 0.25％ :Ce 0.7 Fe 0.3 Schematic diagram of photothermal catalysis and temperature distribution of O2 catalyst. Under the photothermal catalytic conditions, Figure 1 The left side shows the catalytic reaction driven by light, the upper right side shows a schematic diagram of the catalyst layer, and the lower right side shows the temperature distribution on the surface of the catalyst layer under light.

[0088] 3. The batch reaction of photothermal catalysis (pure light conditions) has the following steps:

[0089] a. Weigh the Ce prepared in Examples 1 and 2 respectively. 0.7 Fe 0.3 O2、Ru 0.02％ :Ce 0.7 Fe 0.3 O2, Ru 0.25％ :Ce 0.7 Fe 0.3 O2, Ru 5％ :Ce 0.7 Fe 0.3 O2 catalyst powder (50 mg) was placed in a catalytic reactor equipped with a quartz window for observation and illumination and spread into a thin layer with a diameter of about 4 cm;

[0090] b. Under normal pressure, the reaction gas (CO2:H2:Ar=1:4:95 or 32:64:4 or 48:48:4 or 64:32:4) was introduced into the catalytic reactor and irradiated with a 300W xenon lamp. The reaction gas flow rate was 30sccm (cm under standard conditions). 3 The catalyst was treated for 30 minutes for activation.

[0091] c. Close the reactor's gas outlet, increase the reaction gas flow rate, and quickly increase the reactor pressure to 0.2 MPa before stopping the gas flow. At this pressure, illuminate the reactor with a 300W xenon lamp for 5 minutes or 1 hour, then turn off the light to terminate the reaction. After 5 minutes or 1 hour of reaction, analyze the gas data using a micro gas chromatograph equipped with a micro thermal conductivity detector.

[0092] like Figure 6 As shown 0.25％ :Ce 0.7 Fe 0.3The synchrotron radiation X-ray near-edge absorption spectrum of the O2 material shows the change in the valence state of Fe atoms after the reaction at different temperatures. The decrease in the Fe valence state proves that under the reducing atmosphere provided by hydrogen, the catalyst prepared by the present invention produces more vacancies, thereby promoting the reverse water gas reaction, enhancing the catalyst activity and reducing the reaction temperature.

[0093] like Figure 8 As shown in the figure, through comparative analysis, when the reaction time under light is 1h and the gas concentration is CO2:H2:Ar=1:4:95, different Ru contents (Ru 0.02％ :Ce 0.7 Fe 0.3 O2、Ru 0.25％ :Ce 0.7 Fe 0.3 O2、Ru 5％ :Ce 0.7 Fe 0.3 The photothermal catalytic batch reaction performance of the catalyst of O2) increases with the increase of Ru content, CO2 conversion rate gradually increases, but CO selectivity gradually decreases. 0.25％ :Ce 0.7 Fe 0.3 O2 material is the most preferred. But it is worth noting that even if the Ru doping (Ru 0.02％ :Ce 0.7 Fe 0.3 O2) also effectively improved the performance of the reverse water-gas reaction, demonstrating the effectiveness of our low-noble-metal doping method. Similarly, the performance of the reverse water-gas reaction was also effectively improved when the gas concentrations of CO2:H2:Ar were 32:64:4, 48:48:4, and 64:32:4.

[0094] like Figure 9 As shown, under light irradiation, the reaction time was 5 minutes and Ru 0.25％ :Ce 0.7 Fe 0.3 The photothermal catalytic batch reaction performance of O2 catalyst under different reaction gas concentrations (CO2:H2:Ar=32:64:4, 48:48:4 and 64:32:4) showed that when the gas concentration was CO2:H2:Ar=48:48:4, the production rate of product CO in the reverse water gas reaction was 326mmol g -1 h -1 .

[0095] like Figure 10 As shown, for Ru 0.25％ :Ce 0.7 Fe 0.3The photothermal catalytic mobile phase stability of the O2 catalyst was tested, and it was found that when the gas concentration was CO2:H2:Ar=48:48:4 and a 300W xenon lamp was used for continuous irradiation, after 12 hours of operation, the selectivity of CO and the conversion rate of CO2 remained stable, indicating that the material has good stability.

Claims

1. Application of a photothermal catalytic material with a low noble metal content in a reverse water gas catalytic reaction, wherein the method for preparing the photothermal catalytic material with a low noble metal content comprises the following steps: (1) Dissolve the metal salt, ferric nitrate and cerium nitrate in deionized water, stir evenly and then add dropwise to the NaOH solution, mix and then perform hydrothermal treatment; (2) Collect the precipitate by centrifugation, wash, vacuum dry, grind, calcine the powder at high temperature, and then cool it to obtain the catalyst powder material; The metal in the metal salt in step (1) is any one of Ru, Cu, Ni, Co, and Rh.

2. The use according to claim 1, characterized in that The molar content ratio of the metal salt, ferric nitrate and cerium nitrate in step (1) is 0.02% ~ 0.25%: 0.1 ~ 0.9: 0.9 ~ 0.

1.

3. The use according to claim 1, characterized in that The concentration of the NaOH solution in step (1) is 0.1 mol / L to 10 mol / L.

4. The use according to claim 1, characterized in that The hydrothermal treatment temperature in step (1) is 100° C. to 120° C., and the treatment time is 23 h to 25 h.

5. The use according to claim 1, characterized in that The temperature of the high-temperature calcination in step (2) is 440° C. to 460° C., and the calcination time is 3.5 h to 4 h.

6. The use according to claim 1, characterized in that The application process is: a. Place the catalyst powder into the catalytic reactor and spread it into a thin circular layer; b. Passing reaction gases CO2, H2, and Ar into the catalyst powder and heating or irradiating the catalyst; c. Use gas chromatograph for data analysis.

7. The use according to claim 6, characterized in that In the step b, the volume ratio of CO2, H2, and Ar is any one of 1:4:95, 32:64:4, 48:48:4, and 64:32:4, and the heating or illumination time is 5 minutes to 12 hours.

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