Supported bimetallic catalysts and methods for their preparation

Abstract

The application provides a supported bimetallic catalyst and a preparation method thereof. The supported bimetallic catalyst comprises a rare earth metal oxide carrier and a metal active component supported on the rare earth metal oxide carrier, the metal active component comprises a nickel component and a noble metal component, the content of the nickel component is 0.5-5% by mass based on the total mass of the supported bimetallic catalyst, the content of the noble metal component is 0.01-0.2% by mass, and the content of the rare earth metal oxide carrier is 94.8-99.4% by mass. The supported bimetallic catalyst has excellent catalytic performance, and the VOCs dry reforming reaction activity and stability of the supported bimetallic catalyst are obviously higher than those of traditional single metal catalysts (for example, a nickel-based catalyst and a noble metal-based catalyst).

Description

Technical Field

[0001] This invention relates to a supported bimetallic catalyst, belonging to the field of catalysts. Background Technology

[0002] Volatile organic compounds (VOCs), as one of the main pollutants in flue gas, pose significant threats to the environment and human health. Traditional VOCs treatment methods include adsorption, combustion, and condensation, but these methods suffer from low efficiency, complex operation, and high costs, making it difficult to meet increasingly stringent environmental protection requirements. Therefore, finding efficient and economical VOCs removal technologies has become an important research direction in the current environmental protection field.

[0003] Catalytic reforming is a potential VOCs removal technology. By introducing a suitable catalyst, it utilizes the reforming reaction between CO2 and VOCs to convert VOCs into products such as CO and H2, thus achieving effective removal of VOCs from flue gas. Meanwhile, as CO2 is a major component of flue gas, its utilization helps reduce greenhouse gas emissions and achieve carbon neutrality.

[0004] Nickel (Ni)-based catalysts are the most commonly used catalysts in dry reforming reactions due to their high activation capacity for CH and C-C bonds and their relatively low cost. However, nickel-based catalysts face challenges such as deactivation caused by coke deposition and particle sintering.

[0005] Therefore, finding efficient and economical VOCs removal technologies remains a pressing technical challenge. Summary of the Invention

[0006] The problem the invention aims to solve

[0007] In view of the technical problems existing in the present invention, the purpose of this invention is to provide a supported bimetallic catalyst with excellent catalytic activity and stability in VOCs dry reforming reaction and a method for preparing the same.

[0008] Solution for solving the problem

[0009] To address the aforementioned issues, the inventors conducted in-depth research and discovered that by using nickel (Ni) as the main active component and noble metals as secondary active components to exert a synergistic effect, and by loading Ni and noble metals onto a rare earth metal oxide support via a wet impregnation method, a supported bimetallic catalyst was obtained. Compared to traditional single-metal catalysts (such as nickel (Ni)-based catalysts), the supported bimetallic catalyst of this invention can significantly improve catalytic activity and stability.

[0010] That is, the present invention is as follows.

[0011] [1]. A supported bimetallic catalyst, wherein the supported bimetallic catalyst comprises: a rare earth metal oxide support, and a metal active component supported on the rare earth metal oxide support.

[0012] The active metal component includes a nickel component and a noble metal component.

[0013] Based on the total mass of the supported bimetallic catalyst as 100%, the content of the nickel component is 0.5~5% by mass, the content of the noble metal component is 0.01~0.2% by mass, and the content of the rare earth metal oxide support is 94.8~99.4% by mass.

[0014] [2]. The supported bimetallic catalyst according to [1], wherein the rare earth metal oxide support includes a cerium dioxide support;

[0015] The precious metal component includes at least one of ruthenium, rhodium, platinum and palladium.

[0016] [3]. A method for preparing a supported bimetallic catalyst according to [1] or [2], wherein the preparation method comprises:

[0017] Step A: Mix the nickel source compound and the noble metal source compound to obtain the first mixed solution;

[0018] Step B: The first mixed solution is impregnated on a rare earth metal oxide support and dried to obtain a catalyst precursor;

[0019] Step C: The catalyst precursor is calcined to obtain a supported bimetallic catalyst.

[0020] [4]. According to the preparation method described in [3], wherein step A satisfies at least one of the following properties (a) to (f):

[0021] (a) The nickel source compound is a soluble salt of nickel;

[0022] (b) The nickel source compound is an inorganic salt of nickel;

[0023] (c) The nickel source compound includes at least one of nickel nitrate, nickel acetylacetonate, nickel chloride, nickel sulfate, nickel acetate, and nickel oxalate;

[0024] (d) The noble metal source compound includes a ruthenium source compound, a rhodium source compound, a palladium source compound, or a platinum source compound;

[0025] (e) The precious metal source compound includes at least one of a chloride salt of a precious metal and a nitrate salt of a precious metal;

[0026] (f) The noble metal source compound includes at least one of ruthenium chloride and ruthenium(III) nitrosyl nitrate.

[0027] [5]. According to the preparation method described in [3], wherein step B satisfies at least one of the following properties (g) to (j):

[0028] (g) The rare earth metal oxide support comprises a cerium dioxide support;

[0029] (h) Based on the total mass of the supported bimetallic catalyst being 100%, the content of the rare earth metal oxide support is 94.8~99.4% by mass;

[0030] (i) The drying temperature is 80~120℃;

[0031] (j) The drying time is 6~12h.

[0032] [6]. According to the preparation method described in [3], the calcination treatment includes:

[0033] The first calcination process involves calcination in an air atmosphere; and

[0034] The second calcination step involves reducing and calcining the calcined material obtained in the first calcination step under a reducing atmosphere.

[0035] [7]. According to the preparation method described in [6], in the first calcination step, the first calcination temperature is 300~800℃, the heating rate of the first calcination is 1~10℃ / min, and the holding time of the first calcination temperature in the first calcination step is 2~4h;

[0036] In the second calcination process, the second calcination temperature is 400~800℃, the heating rate of the second calcination is 1~10℃ / min, and the holding time of the second calcination temperature in the second calcination process is 2~4h;

[0037] In the second calcination step, the reducing atmosphere includes hydrogen.

[0038] In the second calcination step, the flow rate of the reducing atmosphere is 80~200 mL / min.

[0039] [8]. Application of the supported bimetallic catalyst according to [1] or [2] in the removal of volatile organic compounds from flue gas.

[0040] [9]. A method for treating waste gas, wherein the method comprises: treating the waste gas using a supported bimetallic catalyst according to [1] or [2].

[0041]

[10] . According to the treatment method described in [9], the waste gas includes at least one of the following: flue gas from thermal power plants, flue gas from industrial kilns, waste gas from cement manufacturing, waste gas from waste incineration, waste gas from glass melting furnaces, and waste gas from steel coke ovens.

[0042] The effects of the invention

[0043] The supported bimetallic catalyst of the present invention has excellent catalytic performance, and its VOCs dry reforming reaction activity and stability are significantly higher than those of traditional single metal catalysts (such as nickel-based catalysts and noble metal-based catalysts).

[0044] The preparation method of the present invention is simple and easy to implement, highly operable, and the raw materials are easy to obtain, making it suitable for mass production. Attached Figure Description

[0045] Figure 1 SEM and HR-TEM images of the CeO2 support prepared in the preparation example are shown.

[0046] Figure 2 The XRD patterns of the catalysts prepared in Examples 1-3 and Comparative Examples 1-3 are shown.

[0047] Figure 3 The VOCs dry reforming reaction performance of the catalysts prepared in Examples 1-3 and Comparative Examples 1-5 is shown in the diagram. Detailed Implementation

[0048] Various exemplary embodiments, features, and aspects of the present invention will be described in detail below. The term "exemplary" as used herein means "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as superior to or better than other embodiments.

[0049] Furthermore, to better illustrate the present invention, numerous specific details are set forth in the following detailed embodiments. Those skilled in the art should understand that the present invention can be practiced without certain specific details. In other instances, methods, means, apparatus, and steps well known to those skilled in the art have not been described in detail in order to highlight the spirit of the present invention.

[0050] Unless otherwise stated, all units used in this specification are international standard units, and all numerical values ​​and ranges appearing in this invention should be understood to include systematic errors that are unavoidable in industrial production.

[0051] In this specification, the word "may" has two meanings: to perform a certain process and not to perform a certain process.

[0052] In this specification, references to "some specific / preferred embodiments," "other specific / preferred embodiments," "implementation," etc., refer to specific elements (e.g., features, structures, properties, and / or characteristics) related to that embodiment, which are included in at least one of the embodiments described herein and may or may not be present in other embodiments. Furthermore, it should be understood that these elements may be combined in any suitable manner in various embodiments.

[0053] In this specification, the range of values ​​referred to as "value A to value B" refers to the range including the endpoint values ​​A and B.

[0054] <Supported bimetallic catalysts>

[0055] This invention provides a supported bimetallic catalyst, comprising: a rare earth metal oxide support, and a metal active component supported on the rare earth metal oxide support.

[0056] The active metal component includes a nickel component and a noble metal component.

[0057] Based on the total mass of the supported bimetallic catalyst as 100%, the content of nickel component is 0.5~5% by mass, the content of ruthenium component is 0.01~0.2% by mass, and the content of rare earth metal oxide support is 94.8~99.4% by mass.

[0058] In this invention, nickel is used as the main active component, which can provide highly efficient catalytic activation. Noble metal components are used as secondary active components to exert a synergistic effect, which can improve the catalytic activity and anti-carbon deposition ability of nickel, so that the entire catalytic system can maintain highly efficient and stable catalytic performance. Rare earth metal oxides are used as supports. Rare earth metal oxides have abundant oxygen vacancies and can have strong metal-support interactions with the supported metal. Thus, the electronic and chemical properties of nickel can be regulated through strong metal-support interactions, thereby improving the catalytic activity and stability of nickel.

[0059] In some specific implementation schemes, based on the total mass of the supported bimetallic catalyst as 100%, the content of nickel component is 0.5% by mass, 1% by mass, 1.5% by mass, 2% by mass, 2.5% by mass, 3% by mass, 3.5% by mass, 4% by mass, 4.5% by mass, or 5% by mass; the content of ruthenium component is 0.01% by mass, 0.05% by mass, 0.08% by mass, 0.1% by mass, 0.13% by mass, 0.15% by mass, 0.18% by mass, or 0.2% by mass; and the content of rare earth metal oxide support is 94.8% by mass, 95% by mass, 95.5% by mass, 96% by mass, 96.5% by mass, 97% by mass, 97.5% by mass, 98% by mass, 98.5% by mass, 99% by mass, or 99.4% by mass.

[0060] In some preferred embodiments, the precious metal component includes at least one of ruthenium, rhodium, rhenium, platinum, palladium, silver, iridium, and gold.

[0061] In some preferred embodiments, the rare earth metal oxide includes cerium dioxide. The reducing oxide support cerium dioxide has abundant oxygen vacancies and can undergo strong metal-support interactions with the supported metal, making it an ideal catalyst support. It exhibits excellent activity in VOCs dry reforming reactions, thereby providing catalysts with excellent catalytic activity and stability.

[0062] In some preferred embodiments, the rare earth oxide support has a nanorod-like structure. The diameter of the rare earth oxide support is preferably 8-17 nm, the length is preferably 30-100 nm, and it is more preferably a porous structure with pores of about 2 nm.

[0063] In some preferred embodiments, the main exposed crystal planes of cerium dioxide exhibit a crystal plane spacing of 0.31 nm, corresponding to the (111) crystal plane.

[0064]

[0065] The method for preparing the supported bimetallic catalyst of the present invention includes:

[0066] Step A: Mix the nickel source compound and the noble metal source compound to obtain the first mixed solution;

[0067] Step B: The first mixed solution described above is impregnated onto a rare earth metal oxide support and dried to obtain the catalyst precursor; and

[0068] Step C: The above catalyst precursor is calcined to obtain a supported bimetallic catalyst.

[0069] In this invention, nickel is used as the main active component, providing highly efficient catalytic activation. Noble metal components are used as secondary active components to exert a synergistic effect, enhancing the catalytic activity and anti-carbon deposition ability of nickel, thus maintaining the overall catalytic system's high efficiency and stable catalytic performance. Ni and noble metals are loaded onto a rare earth metal oxide support via a wet impregnation method. The rare earth metal oxide has abundant oxygen vacancies, allowing for strong metal-support interactions with the supported metal. These strong metal-support interactions modulate the electronic and chemical properties of nickel, thereby improving its catalytic activity and stability. The supported bimetallic catalyst of this invention exhibits excellent catalytic performance, with significantly higher VOCs dry reforming reaction activity and stability compared to single-metal nickel-based catalysts and single-metal noble metal-based catalysts.

[0070] In addition, the preparation method of the present invention is simple, the raw materials are readily available, easy to control, and economically feasible for industrialization.

[0071] Process A

[0072] As a nickel source compound, a nickel salt is preferred, a soluble salt of nickel is more preferred, and an inorganic salt of nickel is even more preferred.

[0073] In some preferred embodiments, the nickel source compound includes at least one of nickel nitrate, nickel acetylacetone, nickel chloride, nickel sulfate, nickel acetate, and nickel oxalate.

[0074] Preferred precious metal source compounds include ruthenium source compounds, rhodium source compounds, palladium source compounds, platinum source compounds, rhenium source compounds, silver source compounds, iridium source compounds, or gold source compounds.

[0075] In some preferred embodiments, the noble metal source compound includes at least one of a chloride salt of a noble metal and a nitrate salt of a noble metal.

[0076] In some preferred embodiments, the noble metal source compound is a ruthenium source compound, more preferably a ruthenium salt, and even more preferably an inorganic salt of ruthenium.

[0077] In some preferred embodiments, the ruthenium source compound is preferably at least one of ruthenium chloride and ruthenium nitrate. These ruthenium salts are readily soluble in water to form a homogeneous aqueous solution.

[0078] In some preferred embodiments, the ruthenium source compound includes ruthenium chloride, ruthenium(III) nitrosyl nitrate, etc.

[0079] In some preferred embodiments, the mass ratio of the nickel source compound to the noble metal source compound is 4:1 to 50:1.

[0080] In some specific implementation schemes, the mass ratio of the nickel source compound to the noble metal source compound is 4:1, 4.5:1, 5:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1, 45:1, or 50:1.

[0081] In some preferred embodiments, the nickel source compound and the noble metal source compound are prepared as an aqueous solution.

[0082] In some preferred embodiments, step A includes:

[0083] Step A1: Mix the nickel source compound with water to obtain mixed solution A;

[0084] Step A2: Mix the noble metal source compound with water to obtain mixed solution B; and

[0085] Step A3: Mix solution A and solution B to obtain the first mixed solution.

[0086] In some preferred embodiments, the nickel source compound and the noble metal source compound are mixed at room temperature (23~25°C).

[0087] In step A1, magnetic stirring can be used to mix the nickel source compound to ensure complete dissolution. The preferred stirring speed is 250-350 r / min, for example, 250 r / min, 300 r / min, or 350 r / min. The stirring time can be 5-10 min, for example, 5 min, 6 min, 7 min, 8 min, 9 min, or 10 min.

[0088] In step A2, magnetic stirring can be used to ensure complete dissolution of the noble metal source compound. The preferred stirring speed is 250–350 r / min, for example, 250 r / min, 300 r / min, or 350 r / min. The stirring time can be 5–10 min, for example, 5 min, 6 min, 7 min, 8 min, 9 min, or 10 min.

[0089] In step A3, to ensure thorough mixing of the nickel source compound and the noble metal source compound, magnetic stirring can be used. The preferred stirring speed is 250–350 r / min, for example, 250 r / min, 300 r / min, or 350 r / min. The stirring time can be 0.5–2 h, for example, 0.5 h, 1 h, 1.5 h, or 2 h.

[0090] In some preferred embodiments, there is no particular limitation on the amount of water used in the above-mentioned steps A1 and A2, but it is preferable to prepare an aqueous solution in which the nickel source compound and the noble metal source compound are fully dissolved.

[0091] Process B

[0092] In some preferred embodiments, a hydrothermal method is used to prepare rare earth metal oxide supports.

[0093] In some preferred embodiments, the rare earth metal oxide support is preferably prepared by mixing a rare earth metal salt solution and an alkaline solution and then carrying out a hydrothermal reaction. After the reaction, the mixture is cooled, and the solid and liquid are separated, washed, and dried to obtain the rare earth metal oxide support.

[0094] In some preferred embodiments, the rare earth metal salt solution includes a cerium salt solution.

[0095] In some preferred embodiments, the cerium salt solution includes at least one of cerium nitrate solution, cerium chloride solution, or cerium sulfate solution.

[0096] In some preferred embodiments, the alkaline solution comprises sodium hydroxide solution and / or potassium hydroxide solution.

[0097] In some preferred embodiments, the mass fraction of the alkali solution is 20-40 wt%.

[0098] In some specific implementations, the mass fraction of the alkali solution is 20wt%, 25wt%, 30wt%, 35wt%, or 40wt%.

[0099] In some preferred embodiments, the hydrothermal reaction temperature is 100~110°C.

[0100] In some specific implementations, the hydrothermal reaction temperature is 100°C, 102°C, 105°C, 108°C, or 110°C.

[0101] In some preferred embodiments, the hydrothermal reaction time is 24-30 hours.

[0102] In some specific implementation schemes, the hydrothermal reaction time is 24h, 25h, 26h, 27h, 28h, 29h, or 30h.

[0103] In some preferred embodiments, the solid-liquid separation includes filtration or centrifugation.

[0104] For centrifugal separation, horizontal or disc centrifuges can be used, for example. In some preferred embodiments, a centrifuge is used to centrifuge at 6000-8000 r / min for 1-5 min.

[0105] In some preferred embodiments, the washing is a water wash, washing the reaction product until it is neutral.

[0106] In some preferred embodiments, the drying can be performed using an oven or the like. There are no particular limitations on the drying temperature and time; for example, the drying temperature can be 80-100°C, and the drying time can be 10-15 hours.

[0107] In some preferred embodiments, the dried solid is further subjected to heat treatment. The preferred heat treatment temperature is 600–700°C; the preferred heat treatment time is 2–3 hours. By setting the heat treatment temperature and time within the above ranges, the size of the rare earth oxide support can be controlled at the nanometer level.

[0108] In some preferred embodiments, the preparation method of rare earth metal oxide support preferably includes: dissolving rare earth metal salt and alkali in water to form solutions, adding the rare earth metal salt solution to the alkali solution, stirring at room temperature for 0.5 to 1 hour, transferring to a high-pressure hydrothermal reactor, cooling to room temperature after hydrothermal reaction, filtering or centrifuging to separate, washing the precipitate with deionized water until the pH value reaches about 7, and then drying and heat-treating to obtain nano-sized rare earth metal oxide support.

[0109] In some preferred embodiments, the rare earth metal oxide support is preferably a cerium dioxide support.

[0110] In this invention, rare earth metal oxides are used as supports. Rare earth metal oxides have abundant oxygen vacancies and can interact strongly with the supported metal. Through this strong metal-support interaction, the electronic and chemical properties of nickel can be modulated, thereby improving the catalytic activity and stability of nickel and providing a catalyst with excellent catalytic activity and stability.

[0111] In some preferred embodiments, nickel and noble metals are loaded onto rare earth metal oxides using an impregnation method.

[0112] In some preferred embodiments, a rare earth metal oxide support is added to a first mixed solution, stirred thoroughly, and then evaporated and dried.

[0113] In some preferred embodiments, the stirring rate is preferably 200~300 r / min; the stirring time is preferably 8~24h, such as 8h, 10h, 12h, 14h, 16h, 18h, 20h, 22h or 24h, to form a suspension.

[0114] In some preferred embodiments, the evaporation drying temperature is preferably 80~120°C, for example 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C or 120°C.

[0115] In some preferred embodiments, the drying time is preferably 6 to 12 hours, for example 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours or 12 hours.

[0116] In some preferred embodiments, the content of rare earth metal oxide support is preferably 94.8 to 99.4% by mass, based on 100% of the total mass of the supported bimetallic catalyst. By controlling the content of rare earth metal oxide support within the above range, the active metal component can be well supported on the support and highly uniformly dispersed on the support. Strong metal-support interactions occur between the rare earth metal oxide support and the supported metal, resulting in a catalyst with excellent catalytic activity and stability.

[0117] Process C

[0118] In step C, the above-mentioned catalyst precursor is calcined to obtain a supported bimetallic catalyst.

[0119] In some preferred embodiments, the calcination treatment preferably includes a multi-stage calcination process, which comprises the following steps:

[0120] The first calcination process involves calcination in an air atmosphere; and

[0121] The second calcination process involves reducing and calcining the calcined material obtained in the first calcination process under a reducing atmosphere.

[0122] In the first calcination step, the preferred calcination temperature is 300~800℃, for example, 300℃, 350℃, 400℃, 450℃, 500℃, 550℃, 600℃, 650℃, 700℃, 750℃, or 800℃. The preferred heating rate for the first calcination is 1~10℃ / min, for example, 1℃ / min, 2℃ / min, 3℃ / min, 4℃ / min, 5℃ / min, 6℃ / min, 7℃ / min, 8℃ / min, 9℃ / min, or 10℃ / min. The preferred holding time for the first calcination temperature in the first calcination step is 2~4 hours, for example, 2 hours, 2.5 hours, 3 hours, 3.5 hours, or 4 hours. The holding time for the first calcination temperature refers to the time after reaching the first calcination temperature and maintaining that temperature.

[0123] In the second calcination process, the second calcination temperature is preferably 400~800℃, for example 400℃, 450℃, 500℃, 550℃, 600℃, 650℃, 700℃, 750℃ or 800℃.

[0124] In the second calcination step, the heating rate of the second calcination is preferably 1~10℃ / min, for example 1℃ / min, 2℃ / min, 3℃ / min, 4℃ / min, 5℃ / min, 6℃ / min, 7℃ / min, 8℃ / min, 9℃ / min or 10℃ / min.

[0125] In the second calcination step, the holding time of the second calcination temperature is preferably 2 to 4 hours, for example, 2 hours, 2.5 hours, 3 hours, 3.5 hours, or 4 hours. The holding time of the second calcination temperature refers to the time after the second calcination temperature is reached and maintained at the second calcination temperature.

[0126] In the second calcination step, the reducing atmosphere for the reduction calcination is preferably a mixture of hydrogen and a protective gas. The protective gas preferably includes nitrogen, an inert gas, etc., and the volume fraction of hydrogen in the mixture is preferably 5% or more and less than 100%, for example, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 99%.

[0127] In the second calcination step, the flow rate of the reducing atmosphere is preferably 80~200 mL / min, for example 80 mL / min, 100 mL / min, 120 mL / min, 140 mL / min, 150 mL / min, 160 mL / min, 180 mL / min or 200 mL / min.

[0128] <Application of Supported Bimetallic Catalysts in the Removal of Volatile Organic Compounds from Flue Gas>

[0129] The present invention also provides the application of the supported bimetallic catalyst according to the present invention in the removal of volatile organic compounds from flue gas.

[0130]

[0131] The present invention provides a method for treating waste gas, comprising: treating the waste gas using a supported bimetallic catalyst according to the present invention.

[0132] In some preferred embodiments, the aforementioned exhaust gases include flue gas from thermal power plants, flue gas from industrial kilns, exhaust gas from cement manufacturing, exhaust gas from waste incineration, exhaust gas from glass melting furnaces, and exhaust gas from steel coke ovens.

[0133] Example

[0134] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0135] Preparation example: Preparation of CeO2 support

[0136] Dissolve 55g of sodium hydroxide (NaOH) in 50mL of deionized water to prepare mixed solution A.

[0137] Dissolve 4.8g of cerium nitrate hexahydrate (Ce(NO3)·6H2O) in 50mL of deionized water to prepare mixed solution B.

[0138] Solution A and solution B were stirred at 300 r / min for 10 min to completely dissolve sodium hydroxide and cerium nitrate hexahydrate.

[0139] While stirring solution A at 300 r / min, add solution B dropwise to solution A to obtain mixed solution C.

[0140] Solution C was stirred at 300 r / min for 1 h at room temperature (25 °C).

[0141] Add 120 mL of deionized water to solution C to obtain solution D.

[0142] Transfer solution D to a 300 mL Teflon-lined stainless steel hydrothermal reactor.

[0143] Place the stainless steel hydrothermal reactor in a 100°C oven for 24 hours, then remove it and allow it to cool naturally at room temperature for 8 hours.

[0144] Centrifuge the resulting solution at 8000 r / min for 2 min, discard the supernatant, and circulate it with deionized water until the pH of the supernatant is 7.

[0145] The resulting solid was dried in an oven at 95 °C for 12 h.

[0146] The dried solid was heated to 700°C at 10°C / min in a muffle furnace under still air, held for 3 hours, and then naturally cooled to room temperature to obtain nanorod CeO2 support.

[0147] Example 1: Preparation of supported bimetallic catalyst 1

[0148] Dissolve 0.0249 g of nickel nitrate hexahydrate (Ni(NO3)2·6H2O) in 50 mL of deionized water to prepare mixed solution E, and stir at 300 r / min for 10 min.

[0149] Dissolve 0.0052 g of ruthenium chloride hexahydrate (RuCl3·6H2O) in 50 mL of deionized water to prepare mixed solution F, and stir at 300 r / min for 10 min.

[0150] While stirring solution E at 300 r / min, add solution F dropwise to solution E to obtain mixed solution G.

[0151] While stirring solution G at 300 r / min, add 1 g of cerium dioxide (CeO2) prepared in the above preparation example to obtain suspension H.

[0152] Suspension H was stirred at 90°C and 300 r / min until all water was evaporated.

[0153] The resulting solid was dried in an oven at 95°C for 12 hours.

[0154] The dried solid was placed in a muffle furnace and heated to 700°C at a rate of 10°C / min in a still air atmosphere, held for 3 hours, and then allowed to cool naturally to room temperature.

[0155] The calcined solid was placed in a tube furnace and heated to 500°C at a hydrogen flow rate of 100 mL / min and a rate of 10°C / min. The temperature was maintained for 2 hours and then naturally cooled to room temperature to obtain the supported bimetallic catalyst 1.

[0156] In this supported bimetallic catalyst 1, based on the total mass of the supported bimetallic catalyst being 100%, the content of nickel component is 0.5% by mass, the content of ruthenium component is 0.2% by mass, and the content of CeO2 support is 99.3% by mass, denoted as 0.5Ni-0.2Ru / CeO2.

[0157] Example 2: Preparation of supported bimetallic catalyst 2

[0158] Dissolve 0.1015g of nickel nitrate hexahydrate (Ni(NO3)2·6H2O) in 50mL of deionized water to prepare mixed solution E, and stir at 300r / min for 10min.

[0159] Dissolve 0.0053 g of ruthenium chloride hexahydrate (RuCl3·6H2O) in 50 mL of deionized water to prepare mixed solution F, and stir at 300 r / min for 10 min.

[0160] While stirring solution E at 300 r / min, add solution F dropwise to solution E to obtain mixed solution G.

[0161] While stirring solution G at 300 r / min, add 1 g of cerium dioxide (CeO2) prepared in the above preparation example to obtain suspension H.

[0162] Suspension H was stirred at 90 °C and 300 r / min until all water was evaporated.

[0163] The resulting solid was dried in an oven at 95 °C for 12 h.

[0164] The dried solid was placed in a muffle furnace and heated to 700°C at a rate of 10°C / min in a still air atmosphere, held for 3 hours, and then allowed to cool naturally to room temperature.

[0165] The calcined solid was heated to 500°C at a hydrogen flow rate of 10°C / min in a tube furnace, held for 2 hours, and then naturally cooled to room temperature to obtain the supported bimetallic catalyst 2.

[0166] In this supported bimetallic catalyst 2, based on the total mass of the supported bimetallic catalyst being 100%, the content of nickel component is 2 by mass, the content of ruthenium component is 0.2 by mass, and the content of CeO2 support is 97.8 by mass, denoted as 2Ni-0.2Ru / CeO2.

[0167] Example 3: Preparation of supported bimetallic catalyst 3

[0168] Dissolve 0.2614 g of nickel nitrate hexahydrate (Ni(NO3)2·6H2O) in 50 mL of deionized water to prepare mixed solution E, and stir at 300 r / min for 10 min.

[0169] Dissolve 0.0055 g of ruthenium chloride hexahydrate (RuCl3·6H2O) in 50 mL of deionized water to prepare mixed solution F, and stir at 300 r / min for 10 min.

[0170] While stirring solution E at 300 r / min, add solution F dropwise to solution E to obtain mixed solution G.

[0171] While stirring solution G at 300 r / min, add 1 g of cerium dioxide (CeO2) prepared in the above preparation example to obtain suspension H.

[0172] Suspension H was stirred at 90 °C and 300 r / min until all water was evaporated.

[0173] The resulting solid was dried in an oven at 95 °C for 12 h.

[0174] The dried solid was placed in a muffle furnace and heated to 700°C at a rate of 10°C / min in a still air atmosphere, held for 3 hours, and then allowed to cool naturally to room temperature.

[0175] The calcined solid was heated to 500°C at a hydrogen flow rate of 10°C / min in a tube furnace, held for 2 hours, and then naturally cooled to room temperature to obtain the supported bimetallic catalyst 3.

[0176] In this supported bimetallic catalyst 3, based on the total mass of the supported bimetallic catalyst being 100%, the content of nickel component is 5% by mass, the content of ruthenium component is 0.2% by mass, and the content of CeO2 support is 94.8% by mass, denoted as 5Ni-0.2Ru / CeO2.

[0177] Example 4

[0178] Dissolve 0.1015g of nickel nitrate hexahydrate (Ni(NO3)2·6H2O) in 50mL of deionized water to prepare mixed solution E, and stir at 300r / min for 10min.

[0179] Dissolve 0.0053 g of ruthenium chloride hexahydrate (RuCl3·6H2O) in 50 mL of deionized water to prepare mixed solution F, and stir at 300 r / min for 10 min.

[0180] While stirring solution E at 300 r / min, add solution F dropwise to solution E to obtain mixed solution G.

[0181] While stirring solution G at 300 r / min, add 1 g of cerium dioxide (CeO2) prepared in the above preparation example to obtain suspension H.

[0182] Suspension H was stirred at 90 °C and 300 r / min until all water was evaporated.

[0183] The resulting solid was dried in an oven at 95°C for 12 hours.

[0184] The dried solid was placed in a muffle furnace and heated to 700°C at a rate of 5°C / min in a still air atmosphere, held for 3 hours, and then allowed to cool naturally to room temperature.

[0185] The calcined solid was heated to 500°C at a hydrogen flow rate of 100 mL / min and a rate of 5°C / min in a tube furnace, held for 2 hours, and then naturally cooled to room temperature to obtain the supported bimetallic catalyst 4.

[0186] In this supported bimetallic catalyst 4, based on the total mass of the bimetallic catalyst being 100%, the content of nickel component is 2% by mass, the content of ruthenium component is 0.2% by mass, and the content of CeO2 support is 97.8% by mass.

[0187] Example 5

[0188] Dissolve 0.1015g of nickel nitrate hexahydrate (Ni(NO3)2·6H2O) in 50mL of deionized water to prepare mixed solution E, and stir at 300r / min for 10min.

[0189] Dissolve 0.0053 g of ruthenium chloride hexahydrate (RuCl3·6H2O) in 50 mL of deionized water to prepare mixed solution F, and stir at 300 r / min for 10 min.

[0190] While stirring solution E at 300 r / min, add solution F dropwise to solution E to obtain mixed solution G.

[0191] While stirring solution G at 300 r / min, add 1 g of cerium dioxide (CeO2) prepared in the above preparation example to obtain suspension H.

[0192] Suspension H was stirred at 90 °C and 300 r / min until all water was evaporated.

[0193] The resulting solid was dried in an oven at 95°C for 12 hours.

[0194] The dried solid was placed in a muffle furnace and heated to 500°C at a rate of 10°C / min in a still air atmosphere, held for 3 hours, and then allowed to cool naturally to room temperature.

[0195] The calcined solid was heated to 700°C at a hydrogen flow rate of 100 mL / min in a tube furnace, held for 2 hours, and then naturally cooled to room temperature to obtain the supported bimetallic catalyst 5.

[0196] In this supported bimetallic catalyst 5, based on the total mass of the bimetallic catalyst being 100%, the content of nickel component is 2% by mass, the content of ruthenium component is 0.2% by mass, and the content of CeO2 support is 97.8% by mass.

[0197] Example 6

[0198] Dissolve 0.1015g of nickel nitrate hexahydrate (Ni(NO3)2·6H2O) in 50mL of deionized water to prepare mixed solution E, and stir at 300r / min for 10min.

[0199] Dissolve 0.0053 g of ruthenium chloride hexahydrate (RuCl3·6H2O) in 50 mL of deionized water to prepare mixed solution F, and stir at 300 r / min for 10 min.

[0200] While stirring solution E at 300 r / min, add solution F dropwise to solution E to obtain mixed solution G.

[0201] While stirring solution G at 300 r / min, add 1 g of cerium dioxide (CeO2) prepared in the above preparation example to obtain suspension H.

[0202] Suspension H was stirred at 90 °C and 300 r / min until all water was evaporated.

[0203] The resulting solid was dried in an oven at 95°C for 12 hours.

[0204] The dried solid was placed in a muffle furnace and heated to 700°C at a rate of 10°C / min in a still air atmosphere, held for 2 hours, and then allowed to cool naturally to room temperature.

[0205] The calcined solid was heated to 500°C at a hydrogen flow rate of 10°C / min in a tube furnace, held for 3 hours, and then naturally cooled to room temperature to obtain the supported bimetallic catalyst 6.

[0206] In this supported bimetallic catalyst 6, based on the total mass of the bimetallic catalyst being 100%, the content of nickel component is 2% by mass, the content of ruthenium component is 0.2% by mass, and the content of CeO2 support is 97.8% by mass.

[0207] Comparative Example 1: Preparation of Ni / CeO2 Single Metal Catalyst 1

[0208] Dissolve 0.0249 g of nickel nitrate hexahydrate (Ni(NO3)2·6H2O) in 50 mL of deionized water to prepare mixed solution E, and stir at 300 r / min for 10 min.

[0209] While stirring solution E at 300 r / min, add 1 g of cerium dioxide (CeO2) prepared in the above preparation example to obtain suspension F.

[0210] Suspension F was stirred at 90 °C and 300 r / min until all water was evaporated.

[0211] The resulting solid was dried in an oven at 95 °C for 12 h.

[0212] The dried solid was placed in a muffle furnace and heated to 700°C at a rate of 10°C / min in a still air atmosphere, held for 3 hours, and then allowed to cool naturally to room temperature.

[0213] The calcined solid was heated to 500°C at a hydrogen flow rate of 10°C / min in a tube furnace, held for 2 hours, and then naturally cooled to room temperature to obtain Ni / CeO2 single metal catalyst 1.

[0214] In this single-metal catalyst 1, with the total mass of the single-metal catalyst being 100%, the content of nickel component is 0.5% by mass, and the content of CeO2 support is 99.5% by mass, denoted as 0.5Ni / CeO2.

[0215] Comparative Example 2: Preparation of Ni / CeO2 Single Metal Catalyst 2

[0216] Dissolve 0.1015g of nickel nitrate hexahydrate (Ni(NO3)2·6H2O) in 50mL of deionized water to prepare mixed solution E, and stir at 300r / min for 10min.

[0217] While stirring solution E at 300 r / min, add 1 g of cerium dioxide (CeO2) prepared in the above preparation example to obtain suspension F.

[0218] Suspension F was stirred at 90 °C and 300 r / min until all water was evaporated.

[0219] The resulting solid was dried in an oven at 95 °C for 12 h.

[0220] The dried solid was placed in a muffle furnace and heated to 700°C at a rate of 10°C / min in a still air atmosphere, held for 3 hours, and then allowed to cool naturally to room temperature.

[0221] The calcined solid was heated to 500°C at a hydrogen flow rate of 10°C / min in a tube furnace, held for 2 hours, and then naturally cooled to room temperature to obtain Ni / CeO2 single metal catalyst 2.

[0222] In this single-metal catalyst 2, with the total mass of the single-metal catalyst being 100%, the content of nickel component is 2 by mass, and the content of CeO2 support is 98 by mass, denoted as 2Ni / CeO2.

[0223] Comparative Example 3: Preparation of Ni / CeO2 Single Metal Catalyst 3

[0224] Dissolve 0.2614 g of nickel nitrate hexahydrate (Ni(NO3)2·6H2O) in 50 mL of deionized water to prepare mixed solution E, and stir at 300 r / min for 10 min.

[0225] While stirring solution E at 300 r / min, add 1 g of cerium dioxide (CeO2) prepared in the above preparation example to obtain suspension F.

[0226] Suspension F was stirred at 90 °C and 300 r / min until all water was evaporated.

[0227] The resulting solid was dried in an oven at 95 °C for 12 h.

[0228] The dried solid was placed in a muffle furnace and heated to 700°C at a rate of 10°C / min in a still air atmosphere, held for 3 hours, and then allowed to cool naturally to room temperature.

[0229] The calcined solid was heated to 500°C at a hydrogen flow rate of 10°C / min in a tube furnace, held for 2 hours, and then naturally cooled to room temperature to obtain Ni / CeO2 single metal catalyst 3.

[0230] In this single-metal catalyst 3, with the total mass of the single-metal catalyst being 100%, the content of nickel component is 5% by mass, and the content of CeO2 support is 95% by mass, denoted as 5Ni / CeO2.

[0231] Comparative Example 4: Preparation of Ru / CeO2 Single Metal Catalyst 4

[0232] Dissolve 0.0052 g of ruthenium chloride hexahydrate (RuCl3·6H2O) in 50 mL of deionized water to prepare mixed solution E, and stir at 300 r / min for 10 min.

[0233] While stirring solution E at 300 r / min, add 1 g of cerium dioxide (CeO2) prepared in the above preparation example to obtain suspension F.

[0234] Suspension F was stirred at 90 °C and 300 r / min until all water was evaporated.

[0235] The resulting solid was dried in an oven at 95 °C for 12 h.

[0236] The dried solid was placed in a muffle furnace and heated to 700°C at a rate of 10°C / min in a still air atmosphere, held for 3 hours, and then allowed to cool naturally to room temperature.

[0237] The calcined solid was heated to 500°C at a hydrogen flow rate of 10°C / min in a tube furnace, held for 2 hours, and then naturally cooled to room temperature to obtain the single metal catalyst 4.

[0238] In this single-metal catalyst 4, based on the total mass of the single-metal catalyst being 100%, the content of the ruthenium component is 0.2% by mass, and the content of the CeO2 support is 99.8% by mass, denoted as 0.2Ru / CeO2.

[0239] Comparative Example 5

[0240] Dissolve 0.1015g of nickel nitrate hexahydrate (Ni(NO3)2·6H2O) in 50mL of deionized water to prepare mixed solution E, and stir at 300r / min for 10min.

[0241] Dissolve 0.0053 g of ruthenium chloride hexahydrate (RuCl3·6H2O) in 50 mL of deionized water to prepare mixed solution F, and stir at 300 r / min for 10 min.

[0242] While stirring solution E at 300 r / min, add solution F dropwise to solution E to obtain mixed solution G.

[0243] Solution G was stirred at 300 r / min, and 1 g of silica (SiO2, Sigma-Aldrich, CAS No.: 7631-86-9) was added to obtain suspension H.

[0244] Suspension H was stirred at 90 °C and 300 r / min until all water was evaporated.

[0245] The resulting solid was dried in an oven at 95°C for 12 hours.

[0246] The dried solid was placed in a muffle furnace and heated to 700°C at a rate of 10°C / min in a still air atmosphere, held for 3 hours, and then allowed to cool naturally to room temperature.

[0247] The calcined solid was heated to 500°C at a hydrogen flow rate of 10°C / min in a tube furnace, held for 2 hours, and then naturally cooled to room temperature to obtain the comparative bimetallic catalyst 1.

[0248] In this comparative bimetallic catalyst 1, with the total mass of the bimetallic catalyst being 100%, the content of nickel component is 2 by mass, the content of ruthenium component is 0.2 by mass, and the content of SiO2 support is 97.8 by mass, denoted as 2Ni-0.2Ru / SiO2.

[0249] <Catalyst Structure Characterization and Catalytic Performance>

[0250] (Structural characterization of rare earth oxide support (cerium dioxide))

[0251] The morphological characteristics of CeO2 were characterized using scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HR-TEM).

[0252] SEM and HR-TEM: such as Figure 1 As shown in (a), the morphological characteristics of CeO2 prepared in the above preparation example were characterized by scanning electron microscopy (SEM), confirming its nanorod structure. High-resolution transmission electron microscopy (HR-TEM) further revealed the structure of the CeO2 nanorods, which had a diameter of 8–17 nm and a length of 30–100 nm, and a large number of pores with a diameter of approximately 2 nm were observed on the nanorods. Figure 1 (b)). The exposed crystal planes of CeO2 show an interplanar spacing of 0.31 nm, which is the characteristic size of the CeO2(111) crystal plane. Figure 1 (c)

[0253] XRD: Figure 2 XRD patterns of the catalysts prepared in Examples 1-3 and Comparative Examples 1-3 are shown. Characteristic peaks at 28.6°, 33.1°, 47.5°, and 56.4° correspond to the (111), (200), (220), and (311) planes of cubic fluorite CeO2. Furthermore, Ni diffraction peaks were observed at 45.5°, 53.0°, and 78.3° in the monometallic catalyst 3 of Comparative Example 3 and the supported bimetallic catalyst 3 of Example 3, representing the (111), (200), and (220) planes of Ni, respectively. However, these Ni diffraction peaks are not present in other catalysts, indicating high Ni dispersion. The catalysts of Examples 1 and 2 had low Ni loadings, therefore no Ni diffraction peaks were detected. Since the Ru loadings of the catalysts of Examples 1-3 were only 0.2%, no Ru diffraction peaks were detected in any of them.

[0254] (Catalytic performance)

[0255] Activity evaluation experiments were conducted on the catalysts prepared in Examples 1-3 and Comparative Examples 1-5. The reaction was carried out in a fixed-bed reactor and maintained at 700°C. The CO2 reactant was controlled at a flow rate of 50 mL / min using a mass flow meter. Acetic acid was selected as the model compound for VOCs. Acetic acid was injected into the vaporizer at a rate of 40 µL / min using a syringe pump. The vaporization chamber temperature was 160°C. N2 was introduced into the vaporization chamber at a flow rate of 30 mL / min, carrying the vaporized acetic acid into the fixed-bed reactor. The gaseous products at the outlet of the quartz tube reactor were analyzed using gas chromatography.

[0256] Figure 3 The VOCs dry reforming reaction performance of the catalysts prepared in Examples 1-3 and Comparative Examples 1-5 is shown. Figure 3 As shown, by comparing the bimetallic catalysts and monometallic catalysts with the same Ni loading (Example 1 vs. Comparative Example 1, Example 2 vs. Comparative Example 2, Example 3 vs. Comparative Example 3), it can be seen that the supported bimetallic catalysts prepared in Examples 1-3 exhibit higher catalytic activity and longer lifespan in the VOCs dry reforming reaction compared to the monometallic catalysts in Comparative Examples 1-3, fully demonstrating their superior catalytic performance. The stability and high efficiency of such supported bimetallic catalysts provide significant potential for industrial applications and are expected to achieve commercialization in the fields of VOCs emission reduction and environmental protection.

[0257] In addition, compared with the Ru / CeO2 monometallic catalyst of Comparative Example 4 and the Ni-Ru / SiO2 catalyst of Comparative Example 5, the supported bimetallic catalysts prepared in Examples 1-3 have higher catalytic activity and longer service life.

[0258] It should be noted that although the technical solution of the present invention has been described with specific examples, those skilled in the art will understand that the present invention should not be limited thereto.

[0259] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. The application of a supported bimetallic catalyst in the dry reforming reaction of volatile organic compounds, characterized in that, The supported bimetallic catalyst comprises: a rare earth metal oxide support, and a metal active component supported on the rare earth metal oxide support. The active metal component includes a nickel component and a noble metal component. Based on the total mass of the supported bimetallic catalyst as 100%, the content of the nickel component is 2-5% by mass, the content of the noble metal component is 0.05-0.2% by mass, and the content of the rare earth metal oxide support is 94.8-99.4% by mass. The precious metal component is a ruthenium component. The rare earth metal oxide support includes a cerium dioxide support.

2. The application according to claim 1, characterized in that, The preparation method of the supported bimetallic catalyst includes: Step A: Mix the nickel source compound and the noble metal source compound to obtain the first mixed solution; Step B: The first mixed solution is impregnated on a rare earth metal oxide support and dried to obtain a catalyst precursor; Step C: The catalyst precursor is calcined to obtain a supported bimetallic catalyst.

3. The application according to claim 2, characterized in that, The process A satisfies at least one of the following properties (a) to (f): (a) The nickel source compound is a soluble salt of nickel; (b) The nickel source compound is an inorganic salt of nickel; (c) The nickel source compound includes at least one of nickel nitrate, nickel acetylacetonate, nickel chloride, nickel sulfate, nickel acetate, and nickel oxalate; (d) The noble metal source compound includes a ruthenium source compound; (e) The precious metal source compound includes at least one of a chloride salt of a precious metal and a nitrate salt of a precious metal; (f) The noble metal source compound includes at least one of ruthenium chloride and ruthenium(III) nitrosyl nitrate.

4. The application according to claim 2, characterized in that, Process B satisfies at least one of the following properties (g) to (j): (g) The rare earth metal oxide support comprises a cerium dioxide support; (h) Based on the total mass of the supported bimetallic catalyst as 100%, the content of the rare earth metal oxide support is 94.8~99.4% by mass; (i) The drying temperature is 80~120℃; (j) The drying time is 6~12h.

5. The application according to claim 2, characterized in that, The calcination process includes: The first calcination process involves calcination in an air atmosphere; and The second calcination step involves reducing and calcining the calcined material obtained from the first calcination step in a reducing atmosphere.

6. The application according to claim 5, characterized in that, In the first calcination process, the first calcination temperature is 300~800℃, the heating rate of the first calcination is 1~10℃ / min, and the holding time of the first calcination temperature in the first calcination process is 2~4h; In the second calcination process, the second calcination temperature is 400~800℃, the heating rate of the second calcination is 1~10℃ / min, and the holding time of the second calcination temperature in the second calcination process is 2~4h; In the second calcination step, the reducing atmosphere includes hydrogen. In the second calcination step, the flow rate of the reducing atmosphere is 80~200 mL / min.

7. A method for treating waste gas, characterized in that, The treatment method includes: using a supported bimetallic catalyst to perform a dry reforming reaction on the volatile organic compounds in the waste gas. The supported bimetallic catalyst comprises: a rare earth metal oxide support, and a metal active component supported on the rare earth metal oxide support. The active metal component includes a nickel component and a noble metal component. Based on the total mass of the supported bimetallic catalyst as 100%, the content of the nickel component is 2-5% by mass, the content of the noble metal component is 0.05-0.2% by mass, and the content of the rare earth metal oxide support is 94.8-99.4% by mass. The precious metal component is a ruthenium component. The rare earth metal oxide support includes a cerium dioxide support.

8. The processing method according to claim 7, characterized in that, The exhaust gas includes at least one of the following: flue gas from thermal power plants, flue gas from industrial kilns, exhaust gas from cement manufacturing, exhaust gas from waste incineration, exhaust gas from glass melting furnaces, and exhaust gas from steel coke ovens.

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