Bifunctional materials, their preparation methods, and methods for treating automobile exhaust.

Abstract

This invention relates to the field of automotive exhaust treatment technology, specifically to a bifunctional material, its preparation method, and a method for treating automotive exhaust. The provided bifunctional material includes a catalyst and a carbon dioxide adsorbent; the catalyst includes an active component and a support; the active component is distributed on the surface and / or inside the support; the active component includes a noble metal. The preparation method of this bifunctional material includes loading a solution of a noble metal precursor onto the support via impregnation to obtain a first intermediate; mixing the carbon dioxide adsorbent precursor and the first intermediate and dispersing them to obtain a second intermediate; and calcining the second intermediate to obtain the bifunctional material. The bifunctional material provided by this invention successfully couples a catalyst and a carbon dioxide adsorbent, developing a bifunctional material that utilizes the synergistic effect of both to achieve near-zero emissions of gaseous pollutants and carbon dioxide during vehicle operation, and exhibits excellent regeneration and recycling performance.

Description

Technical Field

[0001] This invention relates to the field of automotive exhaust treatment technology, specifically to a dual-functional material, its preparation method, and a method for treating automotive exhaust. Background Technology

[0002] The transportation sector 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 a steady rise in emissions from this sector.

[0003] Pollutants emitted from transportation mainly include nitrogen oxides (NOx). x Vehicle emissions include carbon monoxide (CO), hydrocarbons (HCs), and particulate matter (PM). Transportation is also a major contributor to global greenhouse gas emissions. Given the significant role of the transportation sector in pollutant and CO2 emissions, developing vehicle-mounted carbon pollution co-control technologies is of paramount importance.

[0004] Currently, there is no mature technical solution for the synergistic treatment of carbon pollution in automotive exhaust systems. Existing adsorption materials are mostly limited to single functions, such as only adsorbing pollutants or only capturing carbon dioxide. Developing a dual-functional material that can simultaneously treat gaseous pollutants and capture carbon dioxide for automotive exhaust systems to achieve synergistic treatment of carbon pollution in automotive exhaust presents a significant technical challenge. Summary of the Invention

[0005] In view of this, the present invention aims to provide a bifunctional material and its preparation method, as well as a method for treating automobile exhaust gas. This method addresses the carbon pollution system of automobile exhaust gas, simultaneously achieving catalytic degradation of gaseous pollutants and in-situ adsorption and capture of carbon dioxide in automobile exhaust gas. It can achieve the effect of synergistic carbon pollution treatment in the same reactor, without the need for multiple modules to be used in series, thus simplifying the complexity of the capture process.

[0006] In order to solve the above technical problems, this application is implemented as follows:

[0007] This invention provides a bifunctional material comprising a catalyst and a carbon dioxide adsorbent;

[0008] The catalyst comprises an active component and a support; the active component is distributed on the surface and / or interior of the support; the active component comprises a noble metal;

[0009] The carrier includes metal oxides;

[0010] The specific surface area of ​​the carrier is 10m². 2 / g~500m 2 / g.

[0011] In any embodiment, the mass ratio of the catalyst to the carbon dioxide adsorbent is 1:100 to 10:1.

[0012] In any embodiment, the mass content of the precious metal is 0.01% to 20% based on the mass of the catalyst.

[0013] In any embodiment, the noble metal includes at least one of Pt, Pd, and Rh.

[0014] In any embodiment, the diameter of the noble metal is 0.1 nm to 10 nm.

[0015] In any embodiment, the metal oxide includes at least one of Al2O3, TiO2, ZrO2, CeO2, and La2O3.

[0016] In any embodiment, the diameter of the carrier is 10 nm to 100 μm.

[0017] In any embodiment, the carbon dioxide adsorbent includes at least one of CaO, Ca(OH)2, MgO, Mg(OH)2, and hydrotalcite-derived metal oxides.

[0018] In any embodiment, the hydrotalcite-derived metal oxide includes calcium-aluminum hydrotalcite-derived metal oxides.

[0019] In any embodiment, the diameter of the carbon dioxide adsorbent is 10 μm to 1000 μm.

[0020] A second aspect of the present invention provides a method for preparing a bifunctional material, comprising the following steps:

[0021] A solution of a noble metal precursor is selected and loaded onto a support by an impregnation method to obtain the first intermediate.

[0022] The carbon dioxide adsorbent precursor and the first intermediate are mixed and dispersed to obtain the second intermediate;

[0023] The second intermediate was calcined to obtain a bifunctional material.

[0024] In any embodiment, the specific process of the impregnation method is as follows:

[0025] The carrier was immersed in a solution of a noble metal precursor. After immersion, the resulting product was dried and calcined to obtain the first intermediate.

[0026] In any embodiment, the noble metal precursor solution comprises a noble metal salt, which includes at least one of noble metal chloride, noble metal sulfate, and noble metal carbonate.

[0027] In any embodiment, the immersion time is 2h to 24h.

[0028] In any embodiment, the drying temperature is 60°C to 120°C.

[0029] In any embodiment, the calcination temperature is 300℃~600℃, and the calcination time is 4h~8h.

[0030] In any embodiment, the mass ratio of the carbon dioxide adsorbent precursor to the first intermediate is 1:5 to 200:1.

[0031] 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.

[0032] In any embodiment, the calcium-containing compound includes at least one of calcium carbonate, calcium nitrate, calcium acetate, calcium citrate, and calcium hydroxide.

[0033] In any embodiment, the magnesium-containing compound includes at least one of magnesium carbonate, magnesium nitrate, magnesium acetate, magnesium citrate, and magnesium hydroxide.

[0034] In any embodiment, the aluminum-containing compound includes at least one of aluminum carbonate, aluminum nitrate, aluminum acetate, chlorine citrate, and aluminum hydroxide.

[0035] In any embodiment, the dispersion process includes ball milling.

[0036] In any embodiment, the conditions for ball milling are: grinding ball diameter of 5mm to 10cm, ball-to-material ratio of 10:1 to 1:1, rotation speed of 50rpm to 500rpm, and time of 30min to 300min.

[0037] In any embodiment, the calcination temperature is 500℃~800℃, and the calcination time is 2h~24h.

[0038] A third aspect of the present invention provides a method for treating automobile exhaust, comprising the following steps:

[0039] The exhaust gas from automobiles can be treated by passing it into a reactor containing dual-function materials for reaction.

[0040] The beneficial technical effects of the present invention through the above technical solution are as follows:

[0041] This invention successfully couples a catalyst and an adsorbent with a precious metal as the active component into a bifunctional material. The catalyst, with the precious metal as the active component, can efficiently decompose gaseous pollutants in automobile exhaust, generating carbon dioxide, nitrogen, and water. The carbon dioxide adsorbent can adsorb carbon dioxide in situ from automobile exhaust, and simultaneously adsorb carbon dioxide generated from 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 vehicle operation. Furthermore, the catalyst in the provided bifunctional material possesses a high Taman temperature and excellent anti-sintering ability. As a rigid framework material, it can improve the anti-sintering ability of the carbon dioxide adsorbent, avoiding the problem of reduced carbon dioxide adsorption capacity caused by subsequent sintering. Therefore, when the carbon dioxide adsorption in the bifunctional material is saturated, the material can be calcined to achieve desorption and regeneration of the saturated carbon dioxide adsorbent.

[0042] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0043] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof.

[0044] Figure 1 The diagram shown illustrates the working principle of the bifunctional material in this invention.

[0045] Figure 2 The diagram shown is a flowchart of the preparation process of the bifunctional material in this invention.

[0046] Legend in the attached figure:

[0047] 1-1: Noble metals in catalysts;

[0048] 1-2: Support in the catalyst;

[0049] 1-3: Carbon dioxide adsorbent. Detailed Implementation

[0050] This invention discloses a bifunctional material, its preparation method, and a method for treating automobile exhaust. Those skilled in the art can refer to the content of this document and appropriately modify the process parameters to achieve the desired results. It is particularly important to note that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in this invention. The methods and applications of this invention have been described through preferred embodiments. Those skilled in the art can clearly modify or appropriately change and combine the methods and applications described herein without departing from the content, spirit, and scope of this invention to realize and apply the technology of this invention.

[0051] In the description of this invention, the list of items connected by the term "at least one of" or other similar terms may mean any combination of the listed items. For example, if items A and B are listed, then 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, then 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 may contain a single element or multiple elements. Item B may contain a single element or multiple elements. Item C may contain a single element or multiple elements.

[0052] The endpoints and any values ​​of the ranges 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 endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges or individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0053] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0054] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0055] Unless otherwise specified, the terms "comprising" and "including" as used in this application can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0056] In the transportation sector, "carbon pollution synergy" technology aims to reduce gaseous pollutants (such as nitrogen oxides and particulate matter) in exhaust gases and capture carbon dioxide (CO2) through an integrated approach, thereby achieving the dual goals of pollution reduction and carbon reduction. Given the significant role of transportation in pollutant and CO2 emissions, developing vehicle-mounted carbon pollution synergy treatment technologies is highly necessary. However, existing adsorption materials are mostly limited to single functions (such as only adsorbing pollutants or only capturing carbon dioxide), making it difficult to meet the synergistic treatment requirements under dynamic operating conditions of mobile sources. Therefore, developing dual-functional materials that can simultaneously treat gaseous pollutants and capture carbon dioxide for automotive exhaust treatment systems to achieve synergistic carbon pollution treatment of automotive exhaust presents a significant technical challenge.

[0057] In view of this, this application develops a bifunctional material by coupling a high-performance catalyst and a carbon dioxide adsorbent. Utilizing the synergistic effect of the catalyst and carbon dioxide, it simultaneously achieves the catalytic degradation of gaseous pollutants in automobile exhaust and the in-situ adsorption and capture of carbon dioxide. This allows for synergistic carbon pollution control within a single reactor, eliminating the need for multiple modules connected in series and simplifying the capture process. The following provides a more detailed description of this application and its optional embodiments.

[0058] Dual-function materials:

[0059] In some embodiments, the present invention provides a bifunctional material comprising a catalyst and a carbon dioxide adsorbent;

[0060] The catalyst comprises an active component and a support; the active component is distributed on the surface and / or interior of the support; the active component comprises a noble metal;

[0061] The carrier includes metal oxides;

[0062] The specific surface area of ​​the carrier is 10m². 2 / g~500m 2 / g. As an example, the specific surface area of ​​the carrier can be 10m². 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 the two.

[0063] The bifunctional material of this invention comprises a catalyst and an adsorbent with a noble metal as the active component. The catalyst and carbon dioxide adsorbent are mechanically alloyed through a ball milling process, resulting in a randomly mixed distribution. The catalyst with the noble metal as the active component can efficiently decompose gaseous pollutants in automobile exhaust, generating carbon dioxide, nitrogen, and water. The carbon dioxide adsorbent can adsorb carbon dioxide in situ from automobile exhaust, and simultaneously adsorb carbon dioxide generated from 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 vehicle operation. Furthermore, the catalyst uses a metal oxide as a catalyst carrier, which has a high Taman temperature and excellent anti-sintering ability. In the bifunctional material, the catalyst acts as a rigid framework, preventing the sintering of the carbon dioxide adsorbent material and the decrease in adsorption capacity. In other words, the catalyst in the provided bifunctional material has a high Taman temperature and excellent anti-sintering ability; as a rigid framework material, it can improve the anti-sintering ability of the carbon dioxide adsorbent, avoiding the problem of reduced carbon dioxide adsorption capacity caused by subsequent sintering. Therefore, once the carbon dioxide adsorption in the bifunctional material is saturated, the bifunctional material can be calcined to achieve the desorption and regeneration of the saturated carbon dioxide adsorbent.

[0064] In this application, by adjusting the specific surface area of ​​the carrier within the above-mentioned range, it is beneficial to improve the Taman temperature and anti-sintering ability of the carrier, thereby increasing the carbon dioxide capacity after the bifunctional material is regenerated.

[0065] A schematic diagram illustrating the working principle of the dual-functional material of this invention is shown below. Figure 1 As shown, gaseous pollutants in automobile 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 noble metal 1-1 and a support 1-2 in the catalyst. The carbon dioxide in the automobile exhaust and the carbon dioxide (CO2) produced by the decomposition of gaseous pollutants are sealed and fixed in the carbon dioxide adsorbent 1-3, thereby achieving near-zero emissions of gaseous pollutants and carbon dioxide during automobile operation.

[0066] In this invention, the active component in the catalyst is distributed on the surface and / or inside the support. That is, the active component in the catalyst can be distributed on the surface of the support, distributed inside the support, or distributed on both the surface and inside the support.

[0067] Therefore, the bifunctional material provided by this invention, under the synergistic effect of a catalyst with precious metal as active component and metal oxide as support and a carbon dioxide adsorbent, achieves catalytic degradation of gaseous pollutants in automobile exhaust and in-situ adsorption and capture of carbon dioxide. Furthermore, the bifunctional material also has excellent cycle performance, which can extend the service life of the bifunctional catalyst.

[0068] 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 any range between the two.

[0069] In this invention, by controlling the mass ratio of catalyst to carbon dioxide adsorption within the aforementioned range, the efficiency of the catalyst in degrading gaseous pollutants can be maximized, as can the adsorption capacity of the carbon dioxide adsorbent. Furthermore, the excellent regeneration and recycling performance of the bifunctional material can be ensured. If the catalyst content 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 carbon dioxide adsorbent content in the bifunctional material is too high, the degradation efficiency of gaseous pollutants will decrease, and the pollutants cannot be completely decomposed. Simultaneously, an excessive carbon dioxide adsorbent content will weaken the catalyst's skeletal support, and the adsorption capacity of the carbon dioxide adsorbent will decrease after high-temperature sintering.

[0070] In some embodiments, the mass content of the precious metal is 0.01% to 20% based on the mass of the catalyst. As an 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%, or a range between any two, based on the mass of the catalyst.

[0071] In this invention, by controlling the mass content of precious metals in the catalyst within the above-mentioned range, it can be ensured that the precious metals in the catalyst have a high degree of dispersion and sufficient active sites, which can efficiently catalyze the degradation of gaseous pollutants.

[0072] In some embodiments, the precious metal includes, but is not limited to, at least one of Pt, Pd, and Rh; preferably, the precious metal includes all three: Pt, Pd, and Rh.

[0073] In this invention, the noble metal in the catalyst can be loaded onto the support in one or more mixed forms of nanoparticles, atomic clusters, and single atoms.

[0074] In this invention, based on the size of the noble metal active sites in the catalyst, they can be categorized into nanoparticles (particle size 1~100 nm), atomic clusters (size 0.1~1 nm), and single atoms (less than 0.1 nm). Nanoparticles and atomic clusters can be composed of a single type of atom, or two or more types of atoms. A single-atom active site refers to an active site containing only a single atom, but different active sites can be different types of single atoms, and therefore can also be mixtures of different noble metal elements. The same catalyst can simultaneously contain active sites of different forms, such as nanoparticles, atomic clusters, and single atoms.

[0075] 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 between any two.

[0076] In this invention, by controlling the diameter of the noble metal within the above-mentioned range, the active site density and particle stability of the catalyst can be balanced, thereby giving the catalyst higher catalytic efficiency and anti-sintering ability.

[0077] In some embodiments, the metal oxide includes at least one of Al2O3, TiO2, ZrO2, CeO2, and La2O3.

[0078] In this application, the aforementioned metal oxide is used as the catalyst support, which has a high Taman temperature and excellent anti-sintering ability. In the bifunctional material, the catalyst can act as a hard skeleton to prevent the carbon dioxide adsorbent material from sintering and the adsorption capacity from decreasing.

[0079] 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 between any two.

[0080] 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.

[0081] In some embodiments, the hydrotalcite-derived metal oxide includes calcium-aluminum hydrotalcite-derived metal oxides.

[0082] 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.

[0083] Therefore, the bifunctional material provided by this invention, under the synergistic effect of a catalyst with precious metals as active components and metal oxides as carriers and a carbon dioxide adsorbent, achieves catalytic degradation of gaseous pollutants in automobile exhaust and in-situ adsorption and capture of carbon dioxide. Furthermore, the bifunctional material also has excellent cycle performance, which can extend the service life of the bifunctional catalyst.

[0084] Preparation methods of bifunctional materials:

[0085] In some embodiments, a second aspect of the present invention provides a method for preparing a bifunctional material, comprising the following steps:

[0086] A solution of a noble metal precursor is selected and loaded onto a support by an impregnation method to obtain the first intermediate.

[0087] The carbon dioxide adsorbent precursor and the first intermediate are mixed and dispersed to obtain the second intermediate;

[0088] The second intermediate was calcined to obtain a bifunctional material.

[0089] The method for preparing bifunctional materials provided by this invention is as follows: Figure 2 As shown, a first intermediate is obtained by loading noble metals onto a carrier through an impregnation method. This first intermediate is then mechanically alloyed with a precursor of a carbon dioxide adsorbent through a solid-state grinding process. Finally, calcination successfully couples the catalyst and the carbon dioxide adsorbent, yielding a bifunctional material. This bifunctional material can efficiently decompose gaseous pollutants in automobile exhaust and also adsorb carbon dioxide and degraded carbon dioxide in situ from automobile exhaust, achieving synergistic treatment of gaseous pollutants and carbon dioxide in automobile exhaust, thereby achieving near-zero emissions of gaseous pollutants and carbon dioxide during vehicle operation. Furthermore, the preparation process does not involve complex chemical processes such as sol-gel and co-precipitation, making the production process simple and easily scalable for industrial production.

[0090] It should be understood that all the features and advantages described above for "bifunctional materials" also apply to the "preparation method of bifunctional materials", and will not be repeated here.

[0091] In some embodiments, the specific process of the impregnation method is as follows:

[0092] The carrier was immersed in a solution of a noble metal precursor. After immersion, the resulting product was dried and calcined to obtain the first intermediate.

[0093] In some embodiments, the noble metal precursor in the 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.

[0094] It should be noted that precious metal salts are not limited to the substances listed above, and this does not limit the purpose of the present invention. Other similar precious metal salts can also be used in the present invention.

[0095] In some embodiments, the immersion time is 2h to 24h. As an example, the immersion time can be any one of 2h, 5h, 10h, 12h, 15h, 20h, and 24h, or a range between any two.

[0096] In some embodiments, the drying temperature is 60°C to 120°C. As an example, the drying temperature can be any one of 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, and 120°C, or a range between any two.

[0097] In some embodiments, the calcination temperature is 300℃~600℃, and the calcination time is 4h~8h. As an example, the calcination temperature can be any one of 300℃, 350℃, 400℃, 450℃, 500℃, 550℃, and 600℃, or a range between any two; the calcination time can be any one of 4h, 4.5h, 5h, 5.5h, 6h, 6.5h, 7h, 7.5h, and 8h, or a range between any two.

[0098] In this invention, the above-mentioned impregnation involves uniformly loading noble metals onto a support. By controlling the drying and calcination conditions within the above-mentioned range, sufficient active sites and high noble metal dispersion can be formed on the support, thereby improving the catalytic activity, stability, dispersion, and anti-sintering ability of the catalyst.

[0099] As an example, the preparation of the first intermediate includes:

[0100] The carrier is immersed in a solution of a noble metal precursor, such as a solution of a noble metal salt, for 2 h to 24 h. After immersion, the obtained product is dried at 60 °C to 120 °C and then calcined at 300 °C to 600 °C for 4 h to 8 h to obtain the first intermediate.

[0101] 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 between any two.

[0102] In this invention, by controlling the mass ratio of the carbon dioxide adsorbent precursor and the first intermediate within the above-mentioned range, it can be ensured that the catalyst and carbon dioxide adsorbent in the final bifunctional material are in a suitable ratio, 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.

[0103] In some embodiments, the carbon dioxide adsorbent precursor includes, but is not limited to, at least one of a calcium-containing compound, a magnesium-containing compound, and an aluminum-containing compound.

[0104] 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.

[0105] 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.

[0106] In any embodiment, the aluminum-containing compound includes, but is not limited to, at least one of aluminum carbonate, aluminum nitrate, aluminum acetate, chlorine citrate, and aluminum hydroxide.

[0107] In some embodiments, the dispersion process includes ball milling.

[0108] In this invention, a solid-state grinding process based on mechanical alloying is employed to provide a prerequisite for the subsequent preparation of bifunctional materials with uniform structure, thereby improving the sintering resistance of the materials.

[0109] In some embodiments, the ball milling conditions are as follows: the grinding ball diameter is 5mm to 10cm, the ball-to-material ratio is 10:1 to 1:1, the rotation speed is 50rpm to 500rpm, and the time is 30min to 300min. As an example, the grinding ball diameter can be any one of 5mm, 1cm, 2cm, 5cm, 6cm, 8cm, and 10cm, or a range between any two; 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; the rotation speed can be any one of 50rpm, 100rpm, 200rpm, 300rpm, 400rpm, and 500rpm, or a range between any two; and the time can be any one of 30min, 50min, 100min, 150min, 200min, 250min, and 300min, or a range between any two.

[0110] In some embodiments, after the dispersion process is completed, the method further includes: sieving the product obtained after the dispersion process.

[0111] As an example, the preparation of the second intermediate includes:

[0112] The carbon dioxide adsorbent precursor and the first intermediate were mixed at a mass ratio of 1:5 to 200:1, and ball-milled for 30 to 300 minutes at a ball-to-material ratio of 10:1 to 1:1 and a rotation speed of 50 to 500 rpm using grinding balls with a diameter of 5 mm to 10 cm. The resulting product was then sieved to obtain the second intermediate.

[0113] In some embodiments, the calcination temperature is 500℃~800℃, and the calcination time is 2h~24h. As an example, the calcination temperature can be any one of 500℃, 550℃, 600℃, 650℃, 700℃, 750℃, and 800℃, or a range between any two; the calcination time can be any one of 2h, 5h, 10h, 12h, 20h, and 24h, or a range between any two.

[0114] In some embodiments, the calcination atmosphere is an air atmosphere.

[0115] As an example, the preparation of bifunctional materials includes:

[0116] The second intermediate was placed in a muffle furnace and calcined in an air atmosphere at a temperature of 500℃ to 800℃ for 2 hours to 24 hours. After calcination, the material was cooled in the furnace to obtain the bifunctional material.

[0117] A third aspect of the present invention provides a method for treating automobile exhaust, comprising the following steps:

[0118] The exhaust gas from automobiles can be treated by passing it into a reactor containing dual-function materials for reaction.

[0119] In this invention, the provided bifunctional material can reach temperatures above 150°C when heated by automobile exhaust. The catalyst, with precious metals as the active component, is activated, catalytically degrading gaseous pollutants such as CO, HCs, and NOx in the automobile exhaust. The reaction includes CO + O2. - →CO2, HCs + O2 - →CO2 + H2O, NOx + CO - →CO2+N2, etc.; CO2 produced by the decomposition of gaseous pollutants and CO2 originally contained in exhaust gas react with adsorbent materials and are captured, thereby achieving synergistic treatment of gaseous pollutants and CO2, and achieving near-zero emissions of gaseous pollutants and carbon dioxide during vehicle operation.

[0120] In some embodiments, the reaction temperature is 150~200°C, and the reaction time is 20~40 min. 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 between any two, and the reaction time can be any one of 20 min, 25 min, 30 min, 35 min, and 40 min, or a range between any two.

[0121] In this invention, the purpose of the reactor is to immobilize the bifunctional material and prevent its loss due to airflow impact or vibration. Conventional reactors in the art, such as fixed-bed reactors, can be selected. This invention does not limit the specific type of reactor.

[0122] When the carbon dioxide adsorbent in the bifunctional material is saturated, the reactor can be removed and calcined at high temperature to achieve desorption and regeneration of the saturated adsorbent and collection and utilization of CO2. During the high-temperature calcination process, the high specific surface area metal oxide support has a high Taman temperature, which can act as a hard skeleton to prevent the sintering of the carbon dioxide adsorbent material and the decrease in adsorption capacity.

[0123] The present invention will be further described in detail below through examples. All raw materials used in the examples are commercially available.

[0124] Example 1

[0125] The preparation method of bifunctional materials includes the following steps:

[0126] (1) The cerium dioxide carrier was immersed in an aqueous solution of platinum chloride with a concentration of 10 mg / mL for 12 h. After immersion, the product was dried at 80 °C and then calcined at 400 °C for 5 h to obtain the first intermediate.

[0127] (2) The carbon dioxide adsorbent precursor calcium hydroxide and the first intermediate were mixed at a mass ratio of 15:1, and then ball-milled for 60 minutes with grinding balls of 2 cm in diameter at a ball-to-material ratio of 5:1 and a rotation speed of 300 rpm. After ball milling, the product was sieved to obtain the second intermediate.

[0128] (3) The second intermediate was calcined at 700℃ for 4 hours to obtain the bifunctional material Pt / CeO2-CaO; wherein, the mass ratio of catalyst Pt / CeO2 and carbon dioxide adsorbent CaO in the bifunctional material Pt / CeO2-CaO was 1:10, the particle diameter of catalyst Pt / CeO2 was 50 nm, and the specific surface area of ​​support CeO2 in catalyst Pt / CeO2 was 80 m². 2 / g, based on the mass of the catalyst Pt / CeO2, with a Pt mass content of 1% and a carbon dioxide adsorbent CaO particle diameter of 200μm.

[0129] Example 2

[0130] The preparation method of bifunctional materials includes the following steps:

[0131] (1) The carrier aluminum oxide was immersed in an aqueous solution of a mixture of palladium chloride and rhodium chloride with a concentration of 5 mg / mL for 12 h. After immersion, the product was dried at 80 °C and then calcined at 400 °C for 5 h to obtain the first intermediate.

[0132] (2) The carbon dioxide adsorbent precursor calcium acetate and the first intermediate were mixed at a mass ratio of 60:1, and then ball-milled for 120 minutes at a ball-to-material ratio of 3:1 and a rotation speed of 200 rpm using grinding balls with a diameter of 2 cm. After ball milling, the resulting product was sieved to obtain the second intermediate.

[0133] (3) The second intermediate was calcined at 600℃ for 6 h to obtain the bifunctional material Pd-Rh / Al2O3-CaO; wherein, the mass ratio of catalyst Pd-Rh / Al2O3 to carbon dioxide adsorbent CaO in the bifunctional material Pd-Rh / Al2O3-CaO was 1:20; the particle diameter of catalyst Pd-Rh / Al2O3 was 1 μm, and the specific surface area of ​​support Al2O3 in catalyst Pd-Rh / Al2O3 was 68 m². 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.

[0134] Example 3

[0135] The preparation method of bifunctional materials includes the following steps:

[0136] (1) The titanium dioxide carrier was immersed in an aqueous solution of rhodium chloride with a concentration of 10 mg / mL for 12 h. After immersion, the product was dried at 80 °C and then calcined at 400 °C for 5 h to obtain the first intermediate.

[0137] (2) The carbon dioxide adsorbent precursor magnesium hydroxide and the first intermediate were mixed at a mass ratio of 22:1, and then ball-milled for 90 minutes at a ball-to-material ratio of 8:1 and a rotation speed of 400 rpm using grinding balls with a diameter of 2 cm. After ball milling, the resulting product was sieved to obtain the second intermediate.

[0138] (3) The second intermediate was calcined at 650℃ for 5 h to obtain the bifunctional material Rh / TiO2-MgO; wherein, the mass ratio of catalyst Rh / TiO2 and carbon dioxide adsorbent MgO in the bifunctional material Rh / TiO2-MgO was 1:15; the particle diameter of catalyst Rh / TiO2 was 200 nm, and the specific surface area of ​​support TiO2 in catalyst Rh / TiO2 was 120 m². 2 / g; based on the mass of catalyst Rh / TiO2, the mass content of Rh is 0.8%; the particle diameter of carbon dioxide adsorbent MgO is 800μm.

[0139] Example 4

[0140] The preparation method of bifunctional materials includes the following steps:

[0141] (1) The carrier zirconium dioxide was immersed in an aqueous solution of a mixture of platinum chloride and palladium chloride with a concentration of 20 mg / mL for 12 h. After immersion, the product was dried at 80 °C and then calcined at 400 °C for 5 h to obtain the first intermediate.

[0142] (2) The carbon dioxide adsorbent precursors calcium hydroxide and aluminum hydroxide (mass ratio 3:1) and the first intermediate were mixed at a mass ratio of 30:1. Then, the mixture was ball-milled for 150 min with grinding balls of 2 cm diameter at a ball-to-material ratio of 4:1 and a rotation speed of 250 rpm. After the ball milling was completed, the product was sieved to obtain the second intermediate.

[0143] (3) The second intermediate was calcined at 750℃ for 3 hours to obtain the bifunctional material Pt-Pd / ZrO2-calcium aluminum hydrotalcite-derived metal oxide, in which the calcium-aluminum ratio 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 support ZrO2 in the catalyst Pt-Pd / ZrO2 was 50 m². 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 calcium-aluminum hydrotalcite-derived metal oxide carbon dioxide adsorbent is 300μm.

[0144] Example 5

[0145] The preparation method of bifunctional materials includes the following steps:

[0146] (1) Lanthanum oxide support was immersed in an aqueous solution of platinum chloride with a concentration of 5 mg / mL for 12 h. After immersion, the product was dried at 80 °C and then calcined at 400 °C for 5 h to obtain the first intermediate.

[0147] (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. Then, the mixture was ball-milled for 180 min with grinding balls of 2 cm diameter at a ball-to-material ratio of 6:1 and a rotation speed of 350 rpm. After the ball milling was completed, the product was sieved to obtain the second intermediate.

[0148] (3) The second intermediate was calcined at 800℃ for 8 hours to obtain the bifunctional material Pt / La2O3-CaO-MgO; wherein the mass ratio of catalyst Pt / La2O3 and carbon dioxide adsorbent CaO-MgO in the bifunctional material Pt / La2O3-CaO-MgO was 1:15; the particle diameter of catalyst Pt / La2O3 was 800 nm, and the specific surface area of ​​support La2O3 in catalyst Pt / La2O3 was 95 m². 2 / g; based on the mass of catalyst Pt / La2O3, the mass content of Pt is 0.7%; the particle diameter of carbon dioxide adsorbent CaO-MgO is 1000μm.

[0149] Example 6

[0150] The preparation method of bifunctional materials includes the following steps:

[0151] (1) The carrier cerium dioxide was immersed in an aqueous solution of a mixture of platinum chloride, palladium chloride and rhodium chloride with a concentration of 10 mg / mL for 12 h. After immersion, the product was dried at 80 °C and then calcined at 400 °C for 5 h to obtain the first intermediate.

[0152] (2) The carbon dioxide adsorbent precursor calcium hydroxide and the first intermediate were mixed at a mass ratio of 15:1, and then ball-milled for 60 minutes with grinding balls of 2 cm in diameter at a ball-to-material ratio of 5:1 and a rotation speed of 300 rpm. After ball milling, the product was sieved to obtain the second intermediate.

[0153] (3) The second intermediate was calcined at 700℃ for 4 hours to obtain the bifunctional material Pt-Pd-Rh / CeO2-CaO; wherein, the mass ratio of catalyst Pt-Pd-Rh / CeO2 to carbon dioxide adsorbent CaO in the bifunctional material Pt-Pd-Rh / CeO2-CaO was 1:10, the particle diameter of catalyst Pt-Pd-Rh / CeO2 was 50 nm, and the specific surface area of ​​support CeO2 in catalyst Pt-Pd-Rh / CeO2 was 80 m². 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.

[0154] Comparative Example 1

[0155] The preparation method of bifunctional materials includes the following steps:

[0156] (1) The cerium dioxide carrier was immersed in an aqueous solution of platinum chloride with a concentration of 10 mg / mL for 12 h. After immersion, the product was dried at 80 °C and then calcined at 400 °C for 5 h to obtain the first intermediate.

[0157] (2) The carbon dioxide adsorbent precursor calcium hydroxide and the first intermediate were mixed at a mass ratio of 15:1 and calcined at 700℃ for 4 hours to obtain the bifunctional material Pt / CeO2-CaO; wherein, the mass ratio of catalyst Pt / CeO2 to carbon dioxide adsorbent CaO in the bifunctional material Pt / CeO2-CaO was 1:10, the particle diameter of catalyst Pt / CeO2 was 50 nm, and the specific surface area of ​​support CeO2 in catalyst Pt / CeO2 was 80 m². 2 / g, based on the mass of catalyst Pt / CeO2, with Pt content of 1% by mass.

[0158] Comparative Example 2

[0159] The single carbon dioxide adsorbent is CaO, and the particle diameter of CaO is 200 μm.

[0160] Comparative Example 3

[0161] The preparation of bifunctional materials includes the following steps:

[0162] (1) 100g of a mixture of citric acid and calcium nitrate (Ca(NO3)2·4H2O) with a molar ratio of 1:1 was added to 500mL of a water-ethanol mixture with a volume ratio of 4:1. The mixture was stirred with a magnetic stirrer at 50℃ until dissolved. Then, 10g of catalyst Pd-Rh / Al2O3 was dispersed and placed in a water bath at 80℃ for evaporation and dehydration for 8h to form a gel sample. The particle diameter of catalyst Pd-Rh / Al2O3 was 1μm, and the specific surface area of ​​Al2O3 support in catalyst Pd-Rh / Al2O3 was 72m². 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%;

[0163] (2) The gel sample was placed in an oven and dried at 130°C for 2 hours. Then the product was transferred to a muffle furnace and calcined at 400°C for 2 hours to obtain the intermediate.

[0164] (3) After grinding the intermediate, it was calcined at 800℃ for 2 hours to obtain the bifunctional material.

[0165] Test Example 1

[0166] Vehicle exhaust gas treatment performance test: Vehicle exhaust gas was passed into fixed-bed reactors containing the materials prepared in the examples and comparative examples, respectively, and reacted at 200°C for 30 minutes to complete the vehicle exhaust gas treatment. The results of the vehicle exhaust gas treatment performance test are shown in Table 1.

[0167] Table 1. Test results of automotive exhaust gas treatment performance of the materials in Examples 1-6 and Comparative Examples 1-3

[0168]

[0169] Test Example 2

[0170] Anti-sintering ability test: After the materials prepared in the examples and comparative examples in Test Example 1 reactor were saturated with carbon dioxide, the reactor was calcined at 850°C for 2 hours, and then automobile exhaust gas was introduced for reaction. The above process was repeated, and the carbon dioxide adsorption capacity of the material after 10 regenerations, 15 regenerations, and 20 regenerations was tested respectively. Then, the decay rate of the carbon dioxide adsorption capacity of the material after 10 regenerations, 15 regenerations, and 20 regenerations was calculated. The test results are shown in Table 2.

[0171] Table 2. Decrease rate of carbon dioxide adsorption capacity of materials in Examples 1-6 and Comparative Examples 1-3

[0172]

[0173] As shown in Tables 1 and 2, the bifunctional material 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 synergistic carbon pollution control within a single reactor with low system complexity. Furthermore, the bifunctional material prepared in the examples exhibits a carbon dioxide adsorption capacity decay rate of ≤15% after 20 regenerations, demonstrating excellent anti-sintering ability. It is also prepared using a mechanical ball milling alloying process, resulting in low preparation cost. In Comparative Example 1, the material was not mechanically ball-milled and alloyed, resulting in a loose structure and easy sintering. Comparative Example 2 used a single carbon dioxide adsorbent without catalytic components, failing to degrade automobile exhaust. The carbon dioxide adsorbent also lacked anti-sintering components, leading to a loose structure and easy sintering. Comparative Example 3 used a sol-gel method to prepare the bifunctional material, resulting in an uneven structure and poor anti-sintering ability.

[0174] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for treating automobile exhaust, characterized in that, Includes the following steps: The treatment of automobile exhaust can be completed by passing it into a reactor containing dual-functional materials for reaction. The bifunctional material includes a catalyst and a carbon dioxide adsorbent; The catalyst comprises an active component and a support; the active component is distributed on the surface and / or interior of the support; the active component comprises a noble metal; the noble metal comprises at least one of Pt, Pd, and Rh. The carrier includes metal oxides; The specific surface area of ​​the carrier is 10m². 2 / g~500m 2 / g; The carbon dioxide adsorbent includes at least one of CaO and MgO; The metal oxide includes at least one of Al2O3, TiO2, ZrO2, CeO2, and La2O3; The preparation method of the bifunctional material includes the following steps: The carrier was immersed in a solution of a noble metal precursor. After immersion, the resulting product was dried and calcined to obtain the first intermediate. The carbon dioxide adsorbent precursor and the first intermediate are mixed and dispersed to obtain the second intermediate; The second intermediate was calcined to obtain a bifunctional material; The dispersion treatment is ball milling, in which the catalyst and carbon dioxide adsorbent undergo mechanical alloying through the ball milling process.

2. The method for treating automobile exhaust gas 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 method for treating automobile exhaust gas according to claim 1, characterized in that, The catalyst satisfies at least one of the following technical features (1) to (3): (1) Based on the mass of the catalyst, the mass content of the precious metal is 0.01% to 20%; (2) The diameter of the precious metal is 0.1 nm to 10 nm; (3) The diameter of the carrier is 10nm~100μm.

4. The method for treating automobile exhaust gas according to claim 1, characterized in that, The diameter of the carbon dioxide adsorbent is 10 μm to 1000 μm.

5. The method for treating automobile exhaust gas according to claim 1, characterized in that, The noble metal precursor solution includes a noble metal salt, which includes at least one of a noble metal chloride and a noble metal sulfate. The soaking time is 2 hours to 24 hours; And / or, the drying temperature is 60℃~120℃; And / or, the calcination temperature is 300℃~600℃, and the calcination time is 4h~8h.

6. The method for treating automobile exhaust gas according to claim 1, characterized in that, 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 includes at least one of a calcium-containing compound and a magnesium-containing compound; The calcium-containing compound includes at least one of calcium nitrate, calcium acetate, calcium citrate, and calcium hydroxide; The magnesium-containing compound includes at least one of magnesium nitrate, magnesium acetate, magnesium citrate, and magnesium hydroxide.

7. The method for treating automobile exhaust gas according to claim 1, characterized in that, The conditions for ball milling are as follows: the diameter of the grinding balls is 5mm to 10cm, the ball-to-material ratio is 10:1 to 1:1, the rotation speed is 50rpm to 500rpm, and the time is 30min to 300min.

8. The method for treating automobile exhaust gas according to claim 1, characterized in that, The calcination temperature is 500℃~800℃, and the calcination time is 2h~24h.

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