Difunctional material, preparation method thereof and automobile exhaust treatment method

Abstract

The invention relates to the technical field of automobile exhaust treatment, in particular to a bifunctional material, a preparation method thereof and an automobile exhaust treatment method. The provided bifunctional material comprises a catalyst and a carbon dioxide adsorbent, the catalyst comprises an active component and a carrier, the active component is distributed on the surface and / or in the carrier; the active component comprises noble metal. The preparation method of the bifunctional material comprises the following steps: loading a solution of a noble metal precursor onto a carrier through an impregnation method to obtain a first intermediate; mixing a carbon dioxide adsorbent precursor with the first intermediate, and performing dispersion treatment to obtain a second intermediate; and calcining the second intermediate to obtain the bifunctional material. The difunctional material provided by the invention is successfully coupled with a catalyst and a carbon dioxide adsorbent, the difunctional material is developed, near-zero emission of gaseous pollutants and carbon dioxide in the running process of an automobile is realized by utilizing the synergistic effect of the catalyst and the carbon dioxide adsorbent, and the difunctional material has excellent regeneration cycle performance.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile exhaust treatment, and in particular to a dual-function material and a preparation method thereof, and a method for treating automobile exhaust. Background Art

[0002] The transportation industry is one of the major contributors to carbon dioxide and air pollutant emissions. With global economic growth and accelerated urbanization, transportation demand continues to increase, leading to rising emissions from the industry.

[0003] Pollutants emitted by transportation mainly include nitrogen oxides (NO x ), carbon monoxide (CO), hydrocarbons (HCs), and particulate matter (PM). These pollutants not only damage the environment but also have serious impacts on human health. Transportation is also a major contributor to global greenhouse gas emissions. Given the transportation sector's crucial role in pollutant and CO2 emissions, the development of on-board carbon pollution coordinated governance technologies is highly necessary.

[0004] Currently, there are no mature technical solutions for the coordinated management of carbon pollution in vehicle exhaust treatment systems. Existing adsorption materials are often limited to single functions, such as adsorbing pollutants or capturing only carbon dioxide. Developing dual-functional materials for vehicle exhaust treatment systems that can simultaneously treat gaseous pollutants and capture carbon dioxide, thereby achieving coordinated management of carbon pollution in vehicle exhaust, presents significant technical challenges. Summary of the Invention

[0005] In view of this, the present invention is committed to providing a dual-functional material and its preparation method and a method for treating automobile exhaust, which is aimed at the systematic treatment of carbon pollution in automobile exhaust, while realizing the catalytic degradation of gaseous pollutants in automobile exhaust and the in-situ adsorption capture of carbon dioxide. The effect of coordinated carbon pollution treatment can be achieved in the same reactor, without the need for multiple modules to be used in series, which simplifies the complexity of the capture process.

[0006] In order to solve the above technical problems, this application is implemented as follows: The present invention provides a dual-function material, which includes a catalyst and a carbon dioxide adsorbent; The catalyst comprises an active component and a carrier; the active component is distributed on the surface and / or inside of the carrier; the active component comprises a noble metal; The support comprises a metal oxide; The specific surface area of the carrier is 10m 2 / g~500m 2 / g.

[0007] In any embodiment, the mass ratio of the catalyst to the carbon dioxide adsorbent is 1:100 to 10:1.

[0008] In any embodiment, based on the mass of the catalyst, the mass content of the precious metal is 0.01% to 20%.

[0009] In any embodiment, the noble metal includes at least one of Pt, Pd, and Rh.

[0010] In any embodiment, the diameter of the noble metal is 0.1 nm to 10 nm.

[0011] In any embodiment, the metal oxide includes at least one of Al2O3, TiO2, ZrO2, CeO2, and La2O3.

[0012] In any embodiment, the carrier has a diameter of 10 nm to 100 μm.

[0013] In any embodiment, the carbon dioxide adsorbent includes at least one of CaO, Ca(OH)2, MgO, Mg(OH)2, and a hydrotalcite-like derived metal oxide.

[0014] In any embodiment, the hydrotalcite-like derived metal oxide comprises a calcium aluminum hydrotalcite-like derived metal oxide.

[0015] In any embodiment, the diameter of the carbon dioxide adsorbent is 10 μm to 1000 μm.

[0016] A second aspect of the present invention provides a method for preparing a dual-functional material, comprising the following steps: Selecting a solution of a noble metal precursor and loading it onto a support by an impregnation method to obtain a first intermediate; mixing a carbon dioxide adsorbent precursor and a first intermediate, and performing a dispersion treatment to obtain a second intermediate; The second intermediate is calcined to obtain a dual-functional material.

[0017] In any embodiment, the specific process of the impregnation method is: The carrier is placed in a solution of a noble metal precursor for impregnation, and after the impregnation is completed, the obtained product is dried and calcined to obtain a first intermediate.

[0018] In any embodiment, the noble metal precursor in the solution of the noble metal precursor includes a noble metal salt, and the noble metal salt includes at least one of a noble metal chloride, a noble metal sulfate, and a noble metal carbonate.

[0019] In any embodiment, the immersion time is 2 hours to 24 hours.

[0020] In any embodiment, the drying temperature is 60°C to 120°C.

[0021] In any embodiment, the calcination temperature is 300° C. to 600° C., and the calcination time is 4 h to 8 h.

[0022] In any embodiment, the mass ratio of the carbon dioxide adsorbent precursor to the first intermediate is 1:5 to 200:1.

[0023] In any embodiment, the carbon dioxide adsorbent precursor includes at least one of a calcium-containing compound, a magnesium-containing compound, and an aluminum-containing compound.

[0024] In any embodiment, the calcium-containing compound includes at least one of calcium carbonate, calcium nitrate, calcium acetate, calcium citrate, and calcium hydroxide.

[0025] In any embodiment, the magnesium-containing compound includes at least one of magnesium carbonate, magnesium nitrate, magnesium acetate, magnesium citrate, and magnesium hydroxide.

[0026] In any embodiment, the aluminum-containing compound includes at least one of aluminum carbonate, aluminum nitrate, aluminum acetate, chlorocitrate, and aluminum hydroxide.

[0027] In any embodiment, the dispersion process comprises ball milling.

[0028] In any embodiment, the ball milling conditions are: grinding ball diameter of 5 mm to 10 cm, ball-to-material ratio of 10:1 to 1:1, rotation speed of 50 rpm to 500 rpm, and time of 30 min to 300 min.

[0029] In any embodiment, the calcination temperature is 500° C. to 800° C., and the calcination time is 2 h to 24 h.

[0030] A third aspect of the present invention provides a method for treating automobile exhaust, comprising the following steps: The automobile exhaust gas is passed into a reactor filled with dual-functional materials for reaction, thereby completing the treatment of the automobile exhaust gas.

[0031] Through the above technical solution, the beneficial technical effects of the present invention are: The dual-function material of the present invention successfully couples a catalyst with a precious metal as an active component and an adsorbent, wherein the catalyst with a precious metal as an active component can efficiently decompose gaseous pollutants in automobile exhaust to generate carbon dioxide, nitrogen and water; the carbon dioxide adsorbent can in situ adsorb carbon dioxide in automobile exhaust, and can also adsorb carbon dioxide produced by the decomposition of gaseous pollutants, thereby achieving synergistic treatment of gaseous pollutants and carbon dioxide in automobile exhaust, and thus achieving near-zero emissions of gaseous pollutants and carbon dioxide during automobile operation. In addition, the catalyst in the provided dual-function material has a high Tamman temperature and excellent sintering resistance. As a hard skeleton material, it can improve the sintering resistance of the carbon dioxide adsorbent and avoid the problem of a reduction in the carbon dioxide adsorption capacity of the carbon dioxide adsorbent caused by subsequent sintering. Therefore, when the carbon dioxide adsorption in the dual-function material is saturated, the dual-function material can be calcined to achieve desorption and regeneration of the saturated carbon dioxide adsorbent.

[0032] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention, but do not constitute a limitation of the present invention.

[0034] Figure 1 Shown is a schematic diagram of the working principle of the dual-functional material in the present invention.

[0035] Figure 2 Shown is a flow chart for preparing the dual-functional material of the present invention.

[0036] The legend in the accompanying drawings: 1-1: Noble metals in catalysts; 1-2: Support in catalyst; 1-3: Carbon dioxide adsorbent. DETAILED DESCRIPTION

[0037] The present invention discloses a dual-functional material, a method for preparing the same, and a method for treating automobile exhaust. Those skilled in the art can refer to the contents of this document and appropriately improve the process parameters to achieve the desired results. It should be noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in the present invention. The methods and applications of the present invention have been described through preferred embodiments, and relevant personnel can obviously modify or appropriately alter and combine the methods and applications described herein without departing from the content, spirit, and scope of the present invention to implement and apply the technology of the present invention.

[0038] In the description of the present invention, a list of items connected by the term "at least one of" or other similar terms can mean any combination of the listed items. For example, if items A and B are listed, the phrase "at least one of A and B" means only A; only B; or A and B. In another example, if items A, B, and C are listed, the phrase "at least one of A, B, and C" means only A; or only B; only C; A and B (excluding C); A and C (excluding B); B and C (excluding A); or all of A, B, and C. Item A can include a single element or multiple elements. Item B can include a single element or multiple elements. Item C can include a single element or multiple elements.

[0039] The endpoints of the ranges and any values disclosed herein are not limited to the precise ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range or the individual point values, and the individual point values can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0040] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0041] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0042] Unless otherwise specified, the terms "include" and "comprising" used in this application may be open-ended or closed-ended. For example, "include" and "comprising" may mean that other components not listed may also be included or that only the listed components are included.

[0043] In the transportation sector, "carbon pollution synergy" technology aims to reduce gaseous pollutants (such as nitrogen oxides, particulate matter, etc.) in exhaust gas and capture carbon dioxide (CO2) through an integrated approach, thereby achieving the dual goals of pollution reduction and carbon reduction. Given the important position of the transportation sector in pollutant and carbon dioxide emissions, the development of on-board carbon pollution synergistic governance technology is extremely necessary. However, existing adsorption materials are mostly limited to a single function (such as only adsorbing pollutants or only capturing carbon dioxide), which makes it difficult to meet the needs of synergistic governance under dynamic operating conditions of mobile sources. Therefore, how to develop dual-functional materials for automobile exhaust treatment systems that can simultaneously treat gaseous pollutants and capture carbon dioxide to achieve carbon pollution synergistic governance of automobile exhaust is extremely technically challenging.

[0044] In light of this, this application has developed a dual-functional material by coupling a high-performance catalyst with a carbon dioxide adsorbent. This material utilizes the synergistic effect of the catalyst and carbon dioxide to simultaneously catalytically degrade gaseous pollutants in vehicle exhaust and capture carbon dioxide through in-situ adsorption. This allows for synergistic carbon pollution control within the same reactor, eliminating the need for multiple modules in series and simplifying the capture process. The following describes this application and its optional implementations in more detail.

[0045] Dual-function materials: In some embodiments, the present invention provides a bifunctional material comprising a catalyst and a carbon dioxide adsorbent; The catalyst comprises an active component and a carrier; the active component is distributed on the surface and / or inside of the carrier; the active component comprises a noble metal; The support comprises a metal oxide; The specific surface area of the carrier is 10m 2 / g~500m 2 As an example, the specific surface area of the carrier can be 10m 2 / g, 50m 2 / g、100m 2 / g, 200m 2 / g、300m 2 / g, 400m 2 / g and 500m 2 Any point value in / g or any range of values between them.

[0046] The bifunctional material of the present invention includes a catalyst and an adsorbent with a precious metal as an active component, wherein the catalyst and the carbon dioxide adsorbent are mechanically alloyed through a ball milling process, and the two are randomly mixed and distributed. The catalyst with the precious metal as the active component can efficiently decompose gaseous pollutants in automobile exhaust to produce carbon dioxide, nitrogen, and water; the carbon dioxide adsorbent can in situ adsorb carbon dioxide from automobile exhaust, and can also adsorb carbon dioxide produced by the decomposition of gaseous pollutants, achieving synergistic treatment of gaseous pollutants and carbon dioxide in automobile exhaust, thereby achieving near-zero emissions of gaseous pollutants and carbon dioxide during automobile operation. In addition, the catalyst uses a metal oxide as a catalyst carrier, which has a high Tamman temperature and excellent sintering resistance. In the bifunctional material, the catalyst can act as a hard skeleton to prevent sintering of the carbon dioxide adsorbent material and a decrease in adsorption capacity. In other words, the catalyst in the provided bifunctional material has a high Tamman temperature and excellent sintering resistance. As a hard skeleton material, it can improve the sintering resistance of the carbon dioxide adsorbent, avoiding the problem of subsequent sintering causing a decrease in the carbon dioxide adsorption capacity of the carbon dioxide adsorbent. Therefore, when the carbon dioxide adsorption in the dual-functional material is saturated, the dual-functional material can be calcined to achieve desorption and regeneration of the saturated carbon dioxide adsorbent.

[0047] In the present application, by regulating the specific surface area of the carrier within the above range, it is beneficial to increase the Tammann temperature and sintering resistance of the carrier, thereby increasing the carbon dioxide capacity of the dual-functional material after regeneration.

[0048] The working principle diagram of the dual-function material of the present invention is as follows Figure 1 As shown in FIG. Gaseous pollutants in vehicle exhaust, such as carbon monoxide (CO), hydrocarbons (HCs), and nitric oxide (NO), are catalytically degraded into carbon dioxide (CO2), nitrogen (N2), and water (H2O) by a catalyst composed of a precious metal 1-1 and a carrier 1-2. The carbon dioxide in the vehicle exhaust and the carbon dioxide (CO2) produced by the decomposition of the gaseous pollutants are then sealed and fixed in a carbon dioxide adsorbent 1-3, thereby achieving near-zero emissions of gaseous pollutants and carbon dioxide during vehicle operation.

[0049] In the present invention, the active components in the catalyst are distributed on the surface and / or inside the carrier. That is, the active components in the catalyst can be distributed on the surface of the carrier, can be distributed inside the carrier, or can be distributed on the surface and inside the carrier.

[0050] Therefore, the bifunctional material provided by the present invention, under the synergistic action of a catalyst with precious metals as active components and metal oxides as carriers and a carbon dioxide adsorbent, can achieve catalytic degradation of gaseous pollutants in automobile exhaust and in-situ adsorption and capture of carbon dioxide. In addition, the bifunctional material has excellent recycling performance and can extend the service life of the bifunctional catalyst.

[0051] In some embodiments, the mass ratio of the catalyst to the carbon dioxide adsorbent is 1:100 to 10:1. As an example, the mass ratio of the catalyst to the carbon dioxide adsorbent can be any one of 1:100, 1:50, 1:20, 1:10, 1:5, 1:2, 1:1, 2:2, 5:1, and 10:1, or a range therebetween.

[0052] In the present invention, by controlling the mass ratio of catalyst to carbon dioxide adsorbent within the above range, the efficiency of the catalyst in degrading gaseous pollutants can be maximized, the amount of carbon dioxide adsorbent adsorbed can be maximized, and the excellent regeneration and recycling performance of the bifunctional material can be ensured. If the content of catalyst in the bifunctional material is too high, the material's adsorption capacity for carbon dioxide will be insufficient, and carbon dioxide cannot be completely captured. If the content of carbon dioxide adsorbent in the bifunctional material is too high, the degradation efficiency of gaseous pollutants will be reduced, and the pollutants cannot be completely decomposed. At the same time, an excessive content of carbon dioxide adsorbent will weaken the skeletal support of the catalyst, and the adsorption capacity of the carbon dioxide adsorbent will be reduced after high-temperature sintering.

[0053] In some embodiments, the mass content of the precious metal is 0.01% to 20% based on the mass of the catalyst. For example, the mass content of the precious metal can be any one of 0.01%, 0.05%, 0.1%, 0.5%, 1%, 5%, 10%, 15%, and 20% based on the mass of the catalyst, or a range therebetween.

[0054] In the present invention, by controlling the mass content of the noble metal in the catalyst within the above range, it is possible to ensure that the noble metal in the catalyst has a high dispersion, sufficient active sites, and can efficiently catalyze the degradation of gaseous pollutants.

[0055] In some embodiments, the noble metal includes, but is not limited to, at least one of Pt, Pd, and Rh; preferably, the noble metal includes Pt, Pd, and Rh.

[0056] In the present invention, the noble metal in the catalyst can be loaded on the carrier in the form of nanoparticles, atomic clusters and single atoms, or in a mixed form of multiple forms.

[0057] In the present invention, the size of the noble metal active sites in the catalyst can be divided into nanoparticles (particle size 1-100nm), atomic clusters (size 0.1-1nm), and single atoms (less than 0.1nm). Nanoparticles and atomic clusters can be composed of a single type of atoms, or they can be composed of two or more types of atoms. Single-atom active sites refer to active sites with only a single atom, but different active sites can be different types of single atoms, so they can also be mixtures of different noble metal elements. Active sites of different forms, such as nanoparticles, atomic clusters, and single atoms, can coexist in the same catalyst.

[0058] In some embodiments, the diameter of the noble metal is 0.1 nm to 10 nm. As an example, the diameter of the noble metal can be any one of 0.1 nm, 0.5 nm, 1 nm, 2 nm, 4 nm, 5 nm, 6 nm, 8 nm, and 10 nm, or a range therebetween.

[0059] In the present invention, by regulating the diameter of the noble metal within the above range, the active site density and particle stability of the catalyst can be balanced, thereby the catalyst has higher catalytic efficiency and anti-sintering ability.

[0060] In some embodiments, the metal oxide includes at least one of Al2O3, TiO2, ZrO2, CeO2 and La2O3.

[0061] In the present application, the above-mentioned metal oxide is used as a catalyst carrier, which has a higher Tamman temperature and excellent sintering resistance. In the dual-functional material, the catalyst can act as a hard skeleton to prevent the sintering of the carbon dioxide adsorbent material and the decrease in adsorption capacity.

[0062] In some embodiments, the diameter of the carrier is 10 nm to 100 μm. As an example, the diameter of the carrier can be any one of 10 nm, 50 nm, 100 nm, 500 nm, 1 μm, 5 μm, 10 μm, 50 μm and 100 μm, or a range therebetween.

[0063] In some embodiments, the carbon dioxide adsorbent includes, but is not limited to, at least one of CaO, Ca(OH)2, MgO, Mg(OH)2, and hydrotalcite-derived metal oxides.

[0064] In some embodiments, the hydrotalcite-like derived metal oxide comprises a calcium aluminum hydrotalcite-like derived metal oxide.

[0065] In some embodiments, the diameter of the carbon dioxide adsorbent is 10 μm to 1000 μm. As an example, the diameter of the carbon dioxide adsorbent can be any one of 10 μm, 50 μm, 100 μm, 200 μm, 500 μm, 700 μm and 100 μm, or a range between any two of them.

[0066] Therefore, the bifunctional material provided by the present invention, under the synergistic action of a catalyst with precious metals as active components and metal oxides as carriers and a carbon dioxide adsorbent, can achieve catalytic degradation of gaseous pollutants in automobile exhaust and in-situ adsorption and capture of carbon dioxide. In addition, the bifunctional material has excellent recycling performance and can extend the service life of the bifunctional catalyst.

[0067] Preparation method of dual-functional materials: In some embodiments, the second aspect of the present invention provides a method for preparing a dual-functional material, comprising the following steps: Selecting a solution of a noble metal precursor and loading it onto a support by an impregnation method to obtain a first intermediate; mixing a carbon dioxide adsorbent precursor and a first intermediate, and performing a dispersion treatment to obtain a second intermediate; The second intermediate is calcined to obtain a dual-functional material.

[0068] The preparation method of the dual-functional material provided by the present invention is as follows Figure 2 As shown, the precious metal is loaded onto the carrier by an impregnation method to obtain a first intermediate, the first intermediate is then subjected to a solid-state grinding process based on mechanical alloying with a precursor of a carbon dioxide adsorbent, and finally the catalyst and the carbon dioxide adsorbent are successfully coupled by calcination to prepare a bifunctional material. This bifunctional material can not only efficiently decompose gaseous pollutants in automobile exhaust, but also in situ adsorb carbon dioxide in automobile exhaust and carbon dioxide produced by degradation, achieving synergistic treatment of gaseous pollutants and carbon dioxide in automobile exhaust, thereby achieving near-zero emissions of gaseous pollutants and carbon dioxide during automobile operation. In addition, the preparation process does not involve complex chemical processes such as sol-gel and coprecipitation, the production process is simple, and industrial production is easy to achieve.

[0069] It should be understood that all the features and advantages described above for the "dual-functional material" are also applicable to the "method for preparing the dual-functional material" and will not be described in detail here.

[0070] In some embodiments, the specific process of the impregnation method is: The carrier is placed in a solution of a noble metal precursor for impregnation, and after the impregnation is completed, the obtained product is dried and calcined to obtain a first intermediate.

[0071] In some embodiments, the noble metal precursor in the noble metal precursor solution includes, but is not limited to, a noble metal salt; the noble metal salt includes, but is not limited to, at least one of a noble metal chloride, a noble metal sulfate, and a noble metal carbonate.

[0072] It should be noted that the noble metal salts are not limited to the substances listed above, and do not limit the purpose of the present invention. Other similar noble metal salts can also be used in the present invention.

[0073] In some embodiments, the immersion time is 2 hours to 24 hours. As an example, the immersion time can be any one of 2 hours, 5 hours, 10 hours, 12 hours, 15 hours, 20 hours and 24 hours, or a range between any two of them.

[0074] In some embodiments, the drying temperature is 60° C. to 120° C. As an example, the drying temperature may be any one of 60° C., 70° C., 80° C., 90° C., 100° C., 110° C., and 120° C., or a range therebetween.

[0075] In some embodiments, the calcination temperature is 300° C. to 600° C., and the calcination time is 4 h to 8 h. As an example, the calcination temperature can be any one of 300° C., 350° C., 400° C., 450° C., 500° C., 550° C., and 600° C., or a range therebetween, and the calcination time can be any one of 4 h, 4.5 h, 5 h, 5.5 h, 6 h, 6.5 h, 7 h, 7.5 h, and 8 h, or a range therebetween.

[0076] In the present invention, the above-mentioned impregnation is to uniformly load the precious metal on the carrier. By controlling the drying and calcination conditions within the above-mentioned range, sufficient active sites and a higher precious metal dispersion can be formed on the carrier, thereby improving the catalytic activity, stability, dispersion and anti-sintering ability of the catalyst.

[0077] As an example, the preparation of the first intermediate includes: The support is placed in a solution of a noble metal precursor, such as a solution of a noble metal salt, and impregnated for 2 hours to 24 hours. After the impregnation, the obtained product is dried at 60° C. to 120° C., and then calcined at 300° C. to 600° C. for 4 hours to 8 hours to obtain a first intermediate.

[0078] In some embodiments, the mass ratio of the carbon dioxide adsorbent precursor to the first intermediate is 1:5 to 200:1. As an example, the mass ratio of the carbon dioxide precursor to the intermediate can be any one of 1:5, 1:1, 10:1, 20:1, 50:1, 100:1, 150:1, and 200:1, or a range therebetween.

[0079] In the present invention, by controlling the mass ratio of the carbon dioxide adsorbent precursor and the first intermediate within the above-mentioned range, it is possible to ensure that the ratio of the catalyst and the carbon dioxide adsorbent in the final bifunctional material is within an appropriate range, which can maximize the efficiency of the catalyst in degrading gaseous pollutants, maximize the adsorption capacity of the carbon dioxide adsorbent, and ensure that the bifunctional material has excellent regeneration and recycling performance.

[0080] In some embodiments, the carbon dioxide sorbent precursor includes, but is not limited to, at least one of a calcium-containing compound, a magnesium-containing compound, and an aluminum-containing compound.

[0081] In some embodiments, the calcium-containing compound includes, but is not limited to, at least one of calcium carbonate, calcium nitrate, calcium acetate, calcium citrate, and calcium hydroxide.

[0082] In any embodiment, the magnesium-containing compound includes, but is not limited to, at least one of magnesium carbonate, magnesium nitrate, magnesium acetate, magnesium citrate, and magnesium hydroxide.

[0083] In any embodiment, the aluminum-containing compound includes, but is not limited to, at least one of aluminum carbonate, aluminum nitrate, aluminum acetate, aluminum chloride, and aluminum hydroxide.

[0084] In some embodiments, the dispersion process comprises ball milling.

[0085] In the present invention, a solid-state grinding process based on mechanical alloying is adopted to provide a prerequisite for the subsequent preparation of a structurally uniform dual-functional material, thereby improving the material's sintering resistance.

[0086] In some embodiments, the ball milling conditions are as follows: the grinding ball diameter is 5 mm to 10 cm, the ball-to-material ratio is 10:1 to 1:1, the rotation speed is 50 rpm to 500 rpm, and the time is 30 min to 300 min. As an example, the grinding ball diameter can be any one of 5 mm, 1 cm, 2 cm, 5 cm, 6 cm, 8 cm, and 10 cm, or a range between any two of them; the ball-to-material ratio can be any one of 10:1, 8:1, 6:1, 5:1, 4:1, 2:1, and 1:1, or a range between any two of them; the rotation speed is any one of 50 rpm, 100 rpm, 200 rpm, 300 rpm, 400 rpm, and 500 rpm, or a range between any two of them; and the time can be any one of 30 min, 50 min, 100 min, 150 min, 200 min, 250 min, and 300 min, or a range between any two of them.

[0087] In some embodiments, after the dispersion treatment is completed, the method further includes: screening the product obtained after the dispersion treatment is completed.

[0088] As an example, the preparation of the second intermediate includes: The carbon dioxide adsorbent precursor and the first intermediate are mixed in a mass ratio of 1:5 to 200:1, ball milled for 30 min to 300 min using grinding balls with a diameter of 5 mm to 10 cm at a ball-to-material ratio of 10:1 to 1:1 and a rotation speed of 50 rpm to 500 rpm, and then the resulting product is sieved to obtain a second intermediate.

[0089] In some embodiments, the calcination temperature is 500° C. to 800° C., and the calcination time is 2 h to 24 h. As an example, the calcination temperature can be any one of 500° C., 550° C., 600° C., 650° C., 700° C., 750° C., and 800° C., or a range therebetween, and the calcination time can be any one of 2 h, 5 h, 10 h, 12 h, 20 h, and 24 h, or a range therebetween.

[0090] In some embodiments, the calcination atmosphere is an air atmosphere.

[0091] As an example, the preparation of dual-functional materials includes: The second intermediate is placed in a muffle furnace and calcined in an air atmosphere at a temperature of 500°C to 800°C for a time of 2h to 24h. After the calcination is completed, the furnace is cooled to obtain a dual-functional material.

[0092] A third aspect of the present invention provides a method for treating automobile exhaust, comprising the following steps: The automobile exhaust gas is passed into a reactor filled with dual-functional materials for reaction, thereby completing the treatment of the automobile exhaust gas.

[0093] In the present invention, the provided dual-functional material can reach above 150°C when heated by automobile exhaust, and the catalyst with precious metal as active component is activated to catalyze the degradation of gaseous pollutants such as CO, HCs, NOx, etc. in automobile exhaust. The reaction includes CO+O2 - →CO2, HCs+O2 - →CO2+H2O, NOx+CO - →CO2+N2, etc.; the CO2 generated by the decomposition of gaseous pollutants and the CO2 originally contained in the exhaust gas react with the adsorbent material and are captured, thereby achieving coordinated control of gaseous pollutants and CO2, and achieving near-zero emissions of gaseous pollutants and carbon dioxide during vehicle operation.

[0094] In some embodiments, the reaction temperature is 150-200° C., and the reaction time is 20-40 minutes. As an example, the reaction temperature can be any one of 150° C., 160° C., 170° C., 180° C., 190° C., and 200° C., or a range therebetween, and the reaction time can be any one of 20 minutes, 25 minutes, 30 minutes, 35 minutes, and 40 minutes, or a range therebetween.

[0095] In the present invention, the purpose of the reactor is to fix the dual-function material and prevent the dual-function material from being lost due to airflow impact or vibration. Conventional reactors in the art, such as fixed-bed reactors, can be selected. The present invention does not limit the specific type of reactor.

[0096] When the carbon dioxide adsorbent in the dual-functional material is saturated, the reactor can be removed and calcined under high temperature conditions to achieve desorption and regeneration of the saturated adsorbent and collection and utilization of CO2. During the high-temperature calcination process, since the high specific surface area metal oxide support has a higher Tamman temperature, it can act as a hard skeleton to organize the sintering of the carbon dioxide adsorbent material and the decrease in adsorption capacity.

[0097] The present invention is further described in detail below by way of examples. The raw materials used in the examples can all be obtained through commercial sources.

[0098] Example 1 The preparation method of the dual-functional material comprises the following steps: (1) The carrier cerium dioxide was placed in an aqueous solution of platinum chloride with a concentration of 10 mg / mL and impregnated for 12 hours. After the impregnation, the obtained product was dried at 80°C and then calcined at 400°C for 5 hours to obtain a first intermediate; (2) Calcium hydroxide, a precursor of the carbon dioxide adsorbent, and the first intermediate were mixed in a mass ratio of 15:1, and then ball-milled for 60 min using a grinding ball with a diameter of 2 cm at a ball-to-material ratio of 5:1 and a rotation speed of 300 rpm. After the ball milling, the obtained product was sieved to obtain a second intermediate; (3) The second intermediate was calcined at 700 °C for 4 h to obtain a bifunctional material Pt / CeO2-CaO; wherein the mass ratio of the catalyst Pt / CeO2 and the carbon dioxide adsorbent CaO in the bifunctional material Pt / CeO2-CaO is 1:10, the particle diameter of the catalyst Pt / CeO2 is 50 nm, and the specific surface area of the carrier CeO2 in the catalyst Pt / CeO2 is 80 m 2 / g, based on the mass of the catalyst Pt / CeO2, the mass content of Pt is 1%, and the particle diameter of the carbon dioxide adsorbent CaO is 200μm.

[0099] Example 2 The preparation method of the dual-functional material comprises the following steps: (1) The carrier aluminum oxide was placed in an aqueous solution of a mixture of palladium chloride and rhodium chloride at a concentration of 5 mg / mL and impregnated for 12 hours. After the impregnation, the obtained product was dried at 80°C and then calcined at 400°C for 5 hours to obtain a first intermediate; (2) Calcium acetate, a precursor of the carbon dioxide adsorbent, and the first intermediate were mixed in a mass ratio of 60:1, and then ball-milled for 120 min using a grinding ball with a diameter of 2 cm at a ball-to-material ratio of 3:1 and a rotation speed of 200 rpm. After the ball milling, the obtained product was sieved to obtain a second intermediate; (3) The second intermediate was calcined at 600 °C for 6 h to obtain a bifunctional material Pd-Rh / Al2O3-CaO; wherein the mass ratio of the catalyst Pd-Rh / Al2O3 and the carbon dioxide adsorbent CaO in the bifunctional material Pd-Rh / Al2O3-CaO was 1:20; the particle diameter of the catalyst Pd-Rh / Al2O3 was 1 μm, and the specific surface area of the carrier Al2O3 in the catalyst Pd-Rh / Al2O3 was 68 m 2 / g; based on the mass of the catalyst Pd-Rh / Al2O3, the mass content of Pd is 0.5%, and the mass content of Rh is 0.3%; the particle diameter of the carbon dioxide adsorbent CaO is 500μm.

[0100] Example 3 The preparation method of the dual-functional material comprises the following steps: (1) The carrier titanium dioxide was placed in an aqueous solution of rhodium chloride with a concentration of 10 mg / mL and impregnated for 12 hours. After the impregnation, the obtained product was dried at 80°C and then calcined at 400°C for 5 hours to obtain a first intermediate; (2) Mixing the carbon dioxide adsorbent precursor magnesium hydroxide and the first intermediate in a mass ratio of 22:1, and then ball milling them with a grinding ball with a diameter of 2 cm at a ball-to-material ratio of 8:1 and a rotation speed of 400 rpm for 90 minutes. After the ball milling, the obtained product is sieved to obtain the second intermediate; (3) The second intermediate was calcined at 650 °C for 5 h to obtain the bifunctional material Rh / TiO2-MgO; wherein the mass ratio of the catalyst Rh / TiO2 and the carbon dioxide adsorbent MgO in the bifunctional material Rh / TiO2-MgO was 1:15; the particle diameter of the catalyst Rh / TiO2 was 200 nm, and the specific surface area of the carrier TiO2 in the catalyst Rh / TiO2 was 120 m 2 / g; based on the mass of the catalyst Rh / TiO2, the mass content of Rh is 0.8%; the particle diameter of the carbon dioxide adsorbent MgO is 800μm.

[0101] Example 4 The preparation method of the dual-functional material comprises the following steps: (1) The carrier zirconium dioxide was placed in an aqueous solution of a mixture of platinum chloride and palladium chloride at a concentration of 20 mg / mL and impregnated for 12 hours. After the impregnation, the obtained product was dried at 80°C and then calcined at 400°C for 5 hours to obtain a first intermediate; (2) The carbon dioxide adsorbent precursors calcium hydroxide and aluminum hydroxide (mass ratio 3:1) and the first intermediate were mixed in a mass ratio of 30:1, and then ball milled for 150 min using a grinding ball with a diameter of 2 cm at a ball-to-material ratio of 4:1 and a rotation speed of 250 rpm. After the ball milling, the obtained product was sieved to obtain the second intermediate; (3) The second intermediate was calcined at 750 °C for 3 h to obtain a bifunctional material Pt-Pd / ZrO2-calcium-aluminum hydrotalcite-derived metal oxide, wherein the ratio of calcium to aluminum in the calcium-aluminum hydrotalcite-derived metal oxide was 3:1; wherein the mass ratio of the catalyst Pt-Pd / ZrO2 and the carbon dioxide adsorbent calcium-aluminum hydrotalcite-derived metal oxide in the bifunctional material Pt-Pd / ZrO2-calcium-aluminum hydrotalcite-derived metal oxide was 1:20; the particle diameter of the catalyst Pt-Pd / ZrO2 was 500 nm, and the specific surface area of the carrier ZrO2 in the catalyst Pt-Pd / ZrO2 was 50 m 2 / g; based on the mass of the catalyst Pt-Pd / ZrO2, the mass content of Pt is 0.6%, and the mass content of Pd is 0.4%; the particle diameter of the carbon dioxide adsorbent calcium aluminum hydrotalcite-derived metal oxide is 300μm.

[0102] Example 5 The preparation method of the dual-functional material comprises the following steps: (1) The carrier lanthanum oxide was placed in an aqueous solution of platinum chloride with a concentration of 5 mg / mL and impregnated for 12 hours. After the impregnation, the obtained product was dried at 80°C and then calcined at 400°C for 5 hours to obtain a first intermediate; (2) The carbon dioxide adsorbent precursors calcium hydroxide and magnesium hydroxide (mass ratio 6.3:1) and the first intermediate were mixed at a mass ratio of 20:1, and then ball milled for 180 min using a grinding ball with a diameter of 2 cm at a ball-to-material ratio of 6:1 and a rotation speed of 350 rpm. After the ball milling, the obtained product was sieved to obtain the second intermediate; (3) The second intermediate was calcined at 800 °C for 8 h to obtain a bifunctional material Pt / La2O3-CaO-MgO; wherein the mass ratio of the catalyst Pt / La2O3 and the carbon dioxide adsorbent CaO-MgO in the bifunctional material Pt / La2O3-CaO-MgO was 1:15; the particle diameter of the catalyst Pt / La2O3 was 800 nm, and the specific surface area of the carrier La2O3 in the catalyst Pt / La2O3 was 95 m 2 / g; based on the mass of the catalyst Pt / La2O3, the mass content of Pt is 0.7%; the particle diameter of the carbon dioxide adsorbent CaO-MgO is 1000μm.

[0103] Example 6 The preparation method of the dual-functional material comprises the following steps: (1) The carrier cerium dioxide is placed in an aqueous solution of a mixture of platinum chloride, palladium chloride and rhodium chloride at a concentration of 10 mg / mL and impregnated for 12 hours. After the impregnation, the obtained product is dried at 80°C and then calcined at 400°C for 5 hours to obtain a first intermediate; (2) Calcium hydroxide, a precursor of the carbon dioxide adsorbent, and the first intermediate were mixed in a mass ratio of 15:1, and then ball-milled for 60 min using a grinding ball with a diameter of 2 cm at a ball-to-material ratio of 5:1 and a rotation speed of 300 rpm. After the ball milling, the obtained product was sieved to obtain a second intermediate; (3) The second intermediate was calcined at 700 °C for 4 h to obtain a bifunctional material Pt-Pd-Rh / CeO2-CaO; wherein the mass ratio of the catalyst Pt-Pd-Rh / CeO2 and the carbon dioxide adsorbent CaO in the bifunctional material Pt-Pd-Rh / CeO2-CaO was 1:10, the particle diameter of the catalyst Pt-Pd-Rh / CeO2 was 50 nm, and the specific surface area of the carrier CeO2 in the catalyst Pt-Pd-Rh / CeO2 was 80 m 2 / g, based on the mass of the catalyst Pt-Pd-Rh / CeO2, the mass content of Pt is 1%, the mass content of Pd is 0.5%, and the mass content of Rh is 0.3%; the particle diameter of the carbon dioxide adsorbent CaO is 200μm.

[0104] Comparative Example 1 The preparation method of the dual-functional material comprises the following steps: (1) The carrier cerium dioxide was placed in an aqueous solution of platinum chloride with a concentration of 10 mg / mL and impregnated for 12 hours. After the impregnation, the obtained product was dried at 80°C and then calcined at 400°C for 5 hours to obtain a first intermediate; (2) The carbon dioxide adsorbent precursor calcium hydroxide and the first intermediate were mixed in a mass ratio of 15:1 and calcined at 700 °C for 4 h to obtain a bifunctional material Pt / CeO2-CaO; wherein the mass ratio of the catalyst Pt / CeO2 and the carbon dioxide adsorbent CaO in the bifunctional material Pt / CeO2-CaO was 1:10, the particle diameter of the catalyst Pt / CeO2 was 50 nm, and the specific surface area of the carrier CeO2 in the catalyst Pt / CeO2 was 80 m 2 / g, based on the mass of the catalyst Pt / CeO2, the mass content of Pt is 1%.

[0105] Comparative Example 2 The single carbon dioxide adsorbent CaO has a particle diameter of 200 μm.

[0106] Comparative Example 3 The preparation of the dual-functional material comprises the following steps: (1) 100 g of a mixture of citric acid and calcium nitrate (Ca(NO3)2·4H2O) with a molar ratio of 1:1 was added to 500 mL of a water-ethanol mixed solvent with a volume ratio of 4:1; the mixture was stirred at 50°C with a magnetic stirrer until dissolved; then 10 g of the catalyst Pd-Rh / Al2O3 was dispersed and placed in an 80°C water bath for evaporation and dehydration for 8 h to form a gel sample; the particle diameter of the catalyst Pd-Rh / Al2O3 was 1 μm, and the specific surface area of the carrier Al2O3 in the catalyst Pd-Rh / Al2O3 was 72 m 2 / g; based on the mass of the catalyst Pd-Rh / Al2O3, the mass content of Pd is 0.5% and the mass content of Rh is 0.3%; (2) The gel sample was placed in an oven and dried at 130 °C for 2 h, and then the obtained product was transferred to a muffle furnace and calcined at 400 °C for 2 h to obtain an intermediate; (3) The intermediate was ground and calcined at 800 °C for 2 h to obtain the dual-functional material.

[0107] Test Example 1 Automobile exhaust treatment performance test: Automobile exhaust gas was introduced into a fixed-bed reactor containing the materials prepared in the examples and comparative examples, respectively, and reacted at 200°C for 30 minutes to complete automobile exhaust treatment. The results of the automobile exhaust treatment performance test are shown in Table 1.

[0108] Table 1 Test results of automobile exhaust treatment performance of materials in Examples 1 to 6 and Comparative Examples 1 to 3 Test Example 2 Sintering resistance test: After the materials prepared in the examples and comparative examples in the reactor of Test Example 1 were fully adsorbed with carbon dioxide, the reactor was calcined at 850°C for 2 hours, and then automobile exhaust was introduced to react. This process was repeated, and the carbon dioxide adsorption capacity of the materials after 10 regenerations, 15 regenerations, and 20 regenerations was tested. The carbon dioxide adsorption capacity decay rates of the materials after 10 regenerations, 15 regenerations, and 20 regenerations were then calculated. The test results are shown in Table 2.

[0109] Table 2 Decay rate of carbon dioxide adsorption capacity of materials in Examples 1 to 6 and Comparative Examples 1 to 3 As shown in Tables 1 and 2, the dual-functional materials prepared in the examples can simultaneously achieve catalytic degradation of gaseous pollutants in automobile exhaust and in-situ adsorption and capture of carbon dioxide, achieving a coordinated carbon pollution control effect within a single reactor with low system complexity. Furthermore, the dual-functional materials prepared in the examples have a carbon dioxide adsorption capacity decay rate of ≤15% after 20 regenerations, exhibiting excellent sintering resistance. Furthermore, the materials prepared using a mechanical ball milling and alloying process have low production costs. The material in Comparative Example 1 was not subjected to mechanical ball milling and alloying, resulting in a loose structure and easy sintering. Comparative Example 2 used a single carbon dioxide adsorbent without a catalytic component, which was unable to degrade automobile exhaust. The carbon dioxide adsorbent lacked an anti-sintering component, resulting in a loose structure and easy sintering. Comparative Example 3 used a sol-gel method to prepare the dual-functional material, resulting in an uneven structure and poor sintering resistance.

[0110] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A dual-function material, characterized in that: The bifunctional material includes a catalyst and a carbon dioxide adsorbent; The catalyst comprises an active component and a carrier; the active component is distributed on the surface and / or inside of the carrier; the active component comprises a noble metal; The support comprises a metal oxide; The specific surface area of the carrier is 10m 2 / g~500m 2 / g.

2. The dual-function material according to claim 1, characterized in that The mass ratio of the catalyst to the carbon dioxide adsorbent is 1:100 to 10:

1.

3. The dual-function material according to claim 1, characterized in that The catalyst satisfies at least one of the following technical features (1) to (5): (1) Based on the mass of the catalyst, the mass content of the precious metal is 0.01% to 20%; (2) The noble metal includes at least one of Pt, Pd and Rh; (3) The diameter of the noble metal is 0.1 nm to 10 nm; (4) The metal oxide includes at least one of Al2O3, TiO2, ZrO2, CeO2 and La2O3; (5) The diameter of the carrier is 10 nm to 100 μm.

4. The dual-function material according to any one of claims 1 to 3, characterized in that: The carbon dioxide adsorbent comprises at least one of CaO, Ca(OH)2, MgO, Mg(OH)2 and a hydrotalcite-derived metal oxide; The hydrotalcite-like derived metal oxide includes a calcium aluminum hydrotalcite-like derived metal oxide; And / or, the diameter of the carbon dioxide adsorbent is 10 μm to 1000 μm.

5. A method for preparing a dual-functional material, characterized in that: The following steps are involved: Selecting a solution of a noble metal precursor and loading it onto a support by an impregnation method to obtain a first intermediate; mixing a carbon dioxide adsorbent precursor and a first intermediate, and performing a dispersion treatment to obtain a second intermediate; The second intermediate is calcined to obtain a dual-functional material.

6. The method for preparing a dual-functional material according to claim 5, characterized in that: The specific process of the impregnation method is: The carrier is placed in a solution of a noble metal precursor for impregnation, and after the impregnation, the obtained product is dried and calcined to obtain a first intermediate; The noble metal precursor in the noble metal precursor solution includes a noble metal salt, and the noble metal salt includes at least one of a noble metal chloride, a noble metal sulfate, and a noble metal carbonate; The dipping time is 2h~24h; And / or, the drying temperature is 60°C to 120°C; And / or, the calcination temperature is 300° C. to 600° C., and the calcination time is 4 h to 8 h.

7. The method for preparing a dual-functional material according to claim 5, wherein: The mass ratio of the carbon dioxide adsorbent precursor to the first intermediate is 1:5 to 200:1; and / or, the carbon dioxide adsorbent precursor comprises at least one of a calcium-containing compound, a magnesium-containing compound, and an aluminum-containing compound; The calcium-containing compound includes at least one of calcium carbonate, calcium nitrate, calcium acetate, calcium citrate and calcium hydroxide; The magnesium-containing compound includes at least one of magnesium carbonate, magnesium nitrate, magnesium acetate, magnesium citrate and magnesium hydroxide; The aluminum-containing compound includes at least one of aluminum carbonate, aluminum nitrate, aluminum acetate, citric acid chloride and aluminum hydroxide.

8. The method for preparing a dual-functional material according to claim 5, wherein: The dispersion treatment includes ball milling; The ball milling conditions are as follows: the diameter of the grinding balls is 5 mm to 10 cm, the ball-to-material ratio is 10:1 to 1:1, the rotation speed is 50 rpm to 500 rpm, and the time is 30 min to 300 min.

9. The method for preparing a dual-functional material according to any one of claims 5 to 8, characterized in that: The calcination temperature is 500° C. to 800° C., and the calcination time is 2 h to 24 h.

10. A method for treating automobile exhaust, characterized in that: The following steps are involved: The automobile exhaust gas is passed into a reactor containing a dual-functional material for reaction, thereby completing the treatment of the automobile exhaust gas. The dual-function material is the dual-function material according to any one of claims 1 to 4 and / or the dual-function material prepared by the preparation method according to any one of claims 5 to 9.

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