A supported iridium-indium bimetallic catalyst for reductive methylation of aromatic nitro groups and its preparation method and application

Abstract

The present invention discloses a supported iridium-indium bimetallic catalyst for aromatic nitro reduction methylation, and a preparation method and application thereof. The present invention adopts an ultrasonic impregnation method to prepare a highly dispersed supported IrIn bimetallic catalyst, which is used for aromatic nitro reduction methylation reaction with methanol as a green hydrocarbon source, and directly prepares N, N-dimethyl aromatic amine compounds with high selectivity using nitro compounds. The catalyst preparation method of the present invention is simple and easy; the obtained catalyst has high catalytic activity and selectivity for aromatic nitro reduction methylation reaction, and has wide substrate applicability; the reaction system has no exogenous alkali additives, is clean, safe, and has strong operability, and has important economic and use value for the efficient preparation of N-methyl amine compounds and the high value utilization of methanol.

Description

Technical Field

[0001] The invention belongs to the technical field of catalysis, and in particular relates to a supported iridium-indium bimetallic catalyst for aromatic nitro reduction methylation, and a preparation method and application thereof. Background Art

[0002] Methylation reaction is one of the important reactions in organic synthesis and biological processes, and is widely used in the synthesis of fine chemicals such as medicine, agricultural chemicals, dyes, etc. For example, nitrogen-containing drug molecules can be synthesized and modified through N-methylation reaction. Many current best-selling drugs such as antidepressants nimodipine, nicardipine, and non-steroidal antipyretic drugs nimosulide contain N-Me structural units. Traditional methylation reactions use methyl halides, dimethyl sulfate, dimethyl sulfoxide, etc. as methylation reagents, which have problems such as high reagent toxicity and many by-products in the methylation process. Therefore, it is urgent to develop a clean and efficient methylation catalytic conversion method using environmentally friendly compounds as methylation reagents.

[0003] Methanol is an ideal methylation agent with low toxicity, wide sources, biodegradability, safe and convenient storage and transportation. It can make full use of the methyl groups of methanol to construct methyl-containing organic molecules, and has unique advantages such as easy operation, atom economy and environmental friendliness. At the same time, methanol hydrogen has a high mass density (12.5wt%) and can be used as an excellent hydrogen source for reduction conversion. At present, the N-methylation reaction of amine / nitro compounds using methanol as a methyl source or hydrogen source is mainly based on homogeneous Ir and Ru catalytic systems (Angew. Chem. Int. Ed., 2017, 56, 6384; CN110372517A; CN109422654A), which has problems such as cumbersome catalyst preparation, difficult catalyst recovery and separation, and the use of inorganic bases as additives. In the multiphase catalytic system of methanol-amine / nitromethylation, such as the Pt / C (J. Catal. 2019, 371, 47) developed by K. Shimizu et al. and the PdCu / Fe3O4 (Catal. Sci. Technol., 2022, 12, 3524) catalyst developed by BMKim et al., inorganic bases NaOH and K2CO3 are also required as exogenous additives to enable the methylation reaction to proceed smoothly. Using methanol as a hydrocarbon source, the development of a more efficient, clean, and catalyst-recyclable multiphase catalytic system for the direct reduction methylation of nitro compounds has important economic and practical value for the preparation of N-methylamine compounds and the high-value utilization of methanol.

[0004] Improving catalyst activity is the key to developing reductive methylation of nitro compounds using methanol as a hydrocarbon source. Improving metal dispersion and introducing a second metal to form a bimetallic catalyst are effective means to improve the activity of metal catalysts. Improving metal dispersion can improve the intrinsic catalytic activity of supported metals; introducing a second metal can modify and modify the geometry and electronic structure of the original metal, thereby changing the adsorption and activation mode of the bimetallic catalyst on the substrate, thereby improving the catalytic performance. For example, the In-Cu / SiO2-catalyzed hydrogenation of methyl acetate reported by Guo Cuili et al. from Tianjin University (Chin. J. Catal., 2018, 39, 99), In2O3 modification can inhibit the thermal migration and aggregation of Cu nano-ions, improve the dispersion of active metal Cu, and improve the surface Cu + concentration, thereby effectively improving the activity and stability of the Cu / SiO2 catalyst. Professor Wu Dongfang and others from Southeast University reported that CuIn intermetallic compounds catalyze the CO2 hydrogenation to methanol reaction (Int. J. Energy Res. 2022, 46, 1285). On the one hand, the auxiliary metal In can promote the dispersion of the active metal Cu and form a CuIn intermetallic compound with Cu. On the other hand, it forms In2O3 with a high surface oxygen vacancy concentration. The synergistic effect of CuIn intermetallic compounds and In2O3 jointly promotes the activity and selectivity of CO2 hydrogenation to methanol.

[0005] Since there is currently no clean catalytic technology for nitro reductive methylation using methanol as the hydrocarbon source without the addition of inorganic bases, in order to address the problem of methanol being difficult to activate, the development of a highly dispersed bimetallic catalyst that matches the activation and conversion of methanol molecules can provide the possibility for the development of a clean catalytic system technology for aromatic nitro reductive methylation using methanol as the hydrocarbon source. Summary of the invention

[0006] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0007] The present invention is proposed in view of the problems existing in the above-mentioned and / or prior arts, such as high toxicity of the methylating reagent, low atom economy, generation of stoichiometric waste, low catalytic efficiency, complicated post-reaction treatment, additional addition of exogenous inorganic base, and difficulty in reusing the catalyst.

[0008] One of the purposes of the present invention is to provide a supported bimetallic catalyst for aromatic nitro reductive methylation, wherein the obtained catalyst has high catalytic activity and selectivity for aromatic nitro reductive methylation reaction and wide substrate applicability.

[0009] In order to solve the above technical problems, the present invention provides the following technical solution: a supported bimetallic catalyst for reductive methylation of aromatic nitro groups, comprising:

[0010] Carrier;

[0011] A main active component, wherein the main active component is supported on a carrier in the form of nanoclusters or single atoms; and

[0012] Auxiliary metal, the auxiliary metal is in close contact with the main active component and is evenly dispersed on the carrier;

[0013] Wherein, the main active component is Ir; the auxiliary metal is In.

[0014] As a preferred embodiment of the supported iridium-indium bimetallic catalyst for reductive methylation of aromatic nitro groups of the present invention, the loading amount of the main active component in the carrier is 0.1-3.0 wt%.

[0015] As a preferred embodiment of the supported iridium-indium metal catalyst for reductive methylation of aromatic nitro groups of the present invention, the molar ratio of the main active component to the auxiliary metal is 1:0-2.

[0016] As a preferred embodiment of the supported iridium-indium bimetallic catalyst for reductive methylation of aromatic nitro groups of the present invention, the support is one of zinc oxide, cerium oxide, titanium oxide, magnesium oxide and zirconium oxide.

[0017] Another object of the present invention is to provide a method for preparing a supported iridium-indium bimetallic catalyst for reductive methylation of aromatic nitro groups, comprising:

[0018] The carrier is dispersed in deionized water, and the precursor of the main active component and the precursor of the auxiliary metal are added in sequence, and the precursor is evaporated by ultrasonic vibration to obtain a supported bimetallic catalyst precursor after drying;

[0019] The supported bimetallic catalyst precursor is ground and sieved, placed in a reducing atmosphere, and pretreated at 400° C. for 30 to 120 minutes to obtain the supported bimetallic catalyst.

[0020] As a preferred embodiment of the preparation method of the supported iridium indium metal catalyst for the reductive methylation of aromatic nitro groups of the present invention, the precursor of the main active component comprises one of chloroiridic acid hydrate (H2IrCl6〃xH2O), iridium trichloride (IrCl3), iridium acetylacetonate (Ir(acac)3), and iridium acetate (Ir(OAc)3);

[0021] The precursor of the auxiliary metal includes one of indium nitrate hydrate (In(NO3)3〃xH2O), indium trichloride (InCl3), indium acetate (In(C2H3O2)3), and indium acetylacetonate (In(C5H7O2)3).

[0022] Another object of the present invention is to provide the use of the supported iridium-indium bimetallic catalyst for reductive methylation of aromatic nitro groups as described above in the reductive methylation of aromatic nitro compounds using methanol as a hydrocarbon source.

[0023] As a preferred embodiment of the present invention, the specific steps include mixing the supported iridium-indium bimetallic catalyst, solvent, and aromatic nitro compound, reacting for 5 to 24 hours at 120 to 150° C., a nitrogen pressure of 0.5 MPa, and a solvent amount of 3 to 7 mL; wherein the solvent is methanol.

[0024] As a preferred embodiment of the present invention, the aromatic nitro compound is selected from p-nitrotoluene, m-nitrotoluene, o-nitrotoluene, p-nitroanisole, o-nitroanisole, o-phenylnitrobenzene, 4-nitrochlorobenzene, 3-nitrochlorobenzene, 3-nitrofluorobenzene, 3-nitrotrifluorotoluene, methyl 4-nitrobenzoate, methyl 3-nitrobenzoate, methyl 3-nitrophenylacetate, methyl 3-nitrophenylpropionate, 2,4-dimethylnitrobenzene, 3,4-dimethylnitrobenzene, 3,5-dimethylnitrobenzene, 2,4-dimethoxynitrobenzene, 3,4-dimethoxynitrobenzene, and 3-nitropyridine.

[0025] As a preferred embodiment of the present invention, the molar ratio of the main active component in the supported iridium-indium bimetallic catalyst to the aromatic nitro compound is 1:20 to 1:200.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The catalyst preparation method of the invention is simple and easy; the obtained catalyst has high catalytic activity and selectivity for aromatic nitro reduction methylation reaction and wide substrate applicability; the reaction system has no exogenous alkali additives, is clean, safe and highly operable, and has important economic and use value for the efficient preparation of N-methylamine compounds and the high-value utilization of methanol. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0029] Figure 1 0.3wt% IrIn of the present invention 1.5 Spherical aberration corrected transmission electron micrograph of / ZnO catalyst. DETAILED DESCRIPTION

[0030] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0031] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0032] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0033] Unless otherwise specified, the raw materials used in the examples were purchased commercially.

[0034] Example 1

[0035] (1) Taking 0.3wt% Ir / ZnO as an example: add 1.0g ZnO to 10mL pure water, mix with ultrasonic oscillation for 30min, then add the pre-prepared Ir (4mg / mL, 0.75mL) standard solution. After the mixed solution is evaporated to dryness by ultrasonic oscillation in a 75℃ water bath, the obtained light gray powder is placed in a 100℃ oven to dry;

[0036] (2) The powder was then heated from room temperature to 400°C at a heating rate of 5°C / min in a vertical tube furnace under a 10 vol% H2 / Ar atmosphere, and reduced for 2 h to obtain 0.3 wt% Ir / ZnO.

[0037] The noble metal precursor solution was changed, and 0.3wt% Pt / ZnO, 0.3wt% Pd / ZnO, and 0.3wt% Ru / ZnO were obtained in the same way. A series of noble metal catalysts prepared in Example 1 were used in the catalytic reaction of reductive methylation of nitrobenzene to prepare N,N-dimethylaniline, and 2mol% (based on noble metal) of the above catalyst, 5mL methanol and 0.5mmol nitrobenzene were added to a high pressure reactor. The reaction was carried out at 130°C for 5h in a 0.5MPa N2 atmosphere, and the products and yields were analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GCMS). The results are shown in Table 1.

[0038] Table 1

[0039]

[0040] As can be seen from Table 1, when Ir, Pd, and Ru are used as active metals, the conversion rates of nitrobenzene are similar, but when 0.3wt% Pt / ZnO and 0.3wt% Ru / ZnO are used as catalysts, coupling product 4,4'-(p-dimethylamino)diphenylmethane is generated, while 0.3wt% Pd / ZnO has almost no reaction activity.

[0041] Example 2

[0042] The catalyst preparation of this embodiment 2 is consistent with steps (1) and (2) in embodiment 1. In addition to zinc oxide, catalysts with titanium oxide, cerium oxide, magnesium oxide and zirconium oxide as carriers are also prepared, which are named 0.3wt% Ir / ZnO, 0.3wt% Ir / TiO2, 0.3wt% Ir / CeO2, 0.3wt% Ir / MgO and 0.3wt% Ir / ZrO2, respectively.

[0043] The Ir catalysts supported by different carriers prepared in Example 2 were used for the reductive methylation reaction of nitrobenzene. 640 mg of any catalyst, 5 mL of methanol and 0.5 mmol of nitrobenzene were placed in a high pressure reactor and reacted at 0.5 MPa N2 and 130°C for 5 h. The products and yields were analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GCMS), and the results are shown in Table 2.

[0044] Table 2

[0045]

[0046] It can be seen from Table 2 that although the conversion rate of nitrobenzene is 100% when TiO2 and CeO2 are used as carriers, the main products are aniline and N-methylaniline; when MgO and ZrO2 are used as carriers, no N,N-dimethylaniline is generated.

[0047] Example 3

[0048] The catalyst preparation of this Example 3 is consistent with steps (1) and (2) in Example 1. The iridium loading is changed to prepare Ir / ZnO catalysts with loadings of 0.1wt%, 0.3wt%, 1wt% and 3wt%, respectively.

[0049] A series of catalysts with different iridium loadings prepared in Example 3 were used in the catalytic reaction of reductive methylation of nitrobenzene. 2 mol% Ir of the above catalyst, 5 mL of methanol and 0.5 mmol of nitrobenzene were added to a high-pressure reactor, and the reaction was carried out at 0.5 MPaN2 and 130°C for 5 h. The products and yields were analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GCMS). The results are shown in Table 3.

[0050] Table 3

[0051]

[0052]

[0053] It can be seen from Table 3 that when the Ir loading is 0.1wt%, the selectivity of N-methylated products decreases; and when the Ir loading increases to 1wt% and 3wt%, the conversion rate of nitrobenzene decreases significantly, from 47.9% to 15.4% and 2.6%, respectively.

[0054] Example 4

[0055] (1) 0.3 wt% IrIn 1.5 / ZnO as an example: add 1.0g ZnO to 10mL pure water, mix with ultrasonic oscillation for 30min, then add the pre-prepared Ir (4mg / mL, 0.75mL) and In (8mg / mL, 0.34mL) standard solutions. After the mixed solution is further evaporated with ultrasonic oscillation in a 75℃ water bath, the obtained light gray powder is placed in a 100℃ oven for drying;

[0056] (2) The powder was then heated from room temperature to 400°C at a rate of 5°C / min in a vertical tube furnace under a 10 vol% H2 / Ar atmosphere for 2 h to obtain 0.3 wt% IrIn 1.5 / ZnO (the molar ratio of Ir to In is 1:1.5).

[0057] Fixed the amount of Ir metal precursor added and changed the amount of In metal precursor added to prepare 0.3wt% IrIn 0.5 / ZnO, 0.3wt%IrIn 1.0 / ZnO, 0.3wt%IrIn 1.5 / ZnO and 0.3wt%IrIn 2.0 / ZnO.

[0058] The 0.3 wt% IrIn obtained in Example 4 1.5 Spherical aberration-corrected transmission electron microscopy images of the ZnO catalyst are shown in Figure 2 Figure 1 As shown. Figure 1It can be seen that the active metals are highly dispersed on the surface of the ZnO support in the form of single atoms and fully exposed nanoclusters.

[0059] A series of catalysts with different Ir / In molar ratios prepared in Example 4 were used in the catalytic reaction of reductive methylation of nitrobenzene. 2 mol% (based on Ir) of the above catalyst, 5 mL of methanol and 0.5 mmol of nitrobenzene were added to a high-pressure reactor, and the reaction was carried out at 0.5 MPa N2 and 130°C for 5 h. The products and yields were analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GCMS). The results are shown in Table 4.

[0060] Table 4

[0061]

[0062]

[0063] It can be seen from Table 4 that the addition of metal In can significantly improve the activity and selectivity of the catalyst. When the Ir / In molar ratio is 1.5, the nitrobenzene conversion rate is 100% and the selectivity of N,N-dimethylaniline reaches 94.8%. 1.5 / ZnO is the optimal catalyst for this reaction.

[0064] Example 5

[0065] The 0.3 wt% IrIn prepared in Example 4 1.5 / ZnO was used for the reductive methylation reaction of nitrobenzene with different amounts of solvent, and 3 mL, 5 mL, and 7 mL of methanol, 0.5 mmol of nitrobenzene, and 640 mg of 0.3 wt% IrIn were taken respectively. 1.5 The catalyst was reacted in a high pressure reactor under 0.5 MPa N2 and 130°C for 5 h. The product and yield were analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GCMS). The results are shown in Table 5.

[0066] Table 5

[0067] Amount of solvent (mL) Conversion rate (%) N,N-dimethylaniline yield (%) 3 100 39.2 5 100 94.8 7 100 85.2

[0068] It can be seen from Table 5 that when the amount of methanol is 5 mL, the catalytic reaction has the best activity and the N,N-dimethylaniline reaches the highest yield of 94.8%.

[0069] Example 6

[0070] (1) 0.3 wt% IrIn 1.5Take ZnO as an example: add 1.0g ZnO to 10mL pure water, mix with ultrasonic oscillation for 30min, then add the pre-prepared Ir (4mg / mL, 0.75mL) and In (8mg / mL, 0.34mL) standard solutions. After the mixed solution is evaporated to dryness in a 75℃ water bath with ultrasonic oscillation, the obtained light gray powder is placed in a 100℃ oven to dry;

[0071] (2) The powder was then heated from room temperature to 400°C at a rate of 5°C / min in a vertical tube furnace under a 10 vol% H2 / Ar atmosphere for 2 h to obtain 0.3 wt% IrIn 1.5 / ZnO.

[0072] In the same way, the catalyst carrier was changed to prepare 0.3wt% IrIn 1.5 / TiO2、0.3wt%IrIn 1.5 / MgO, 0.3wt%IrIn 1.5 / ZrO2, and 0.3wt%IrIn 1.5 / CeO2.

[0073] The IrIn prepared in Example 6 was loaded on different carriers. 1.5 The catalyst was used for the reductive methylation reaction of nitrobenzene. 0.5 mmol nitrobenzene, 5 mL methanol and 640 mg of any catalyst were placed in a high pressure reactor and reacted at 0.5 MPa N2 and 130°C for 5 h. The products and yields were analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GCMS). The results are shown in Table 6.

[0074] Table 6

[0075]

[0076]

[0077] It can be seen from Table 6 that compared with the single metal Ir catalysts loaded on different carriers, the IrIn 1.5 The metal In has a universal effect on the performance of the catalytic reduction methylation of loaded Ir, among which 0.3wt% IrIn 1.5 / ZnO still has the best catalytic performance.

[0078] Example 7

[0079] The 0.3 wt% IrIn prepared in Example 4 1.5 / ZnO catalyst was used in the reductive methylation reaction of different aromatic nitro compounds. The amount of aromatic nitro compound used was 0.5 mmol, the solvent was 5 mL methanol, the reaction was carried out at 0.5 MPa N2, 130-150°C for 5-24 h, and the product and yield were analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GCMS). The results are shown in Table 7.

[0080] Table 7

[0081]

[0082]

[0083]

[0084] It can be seen from Table 7 that aromatic nitro compounds containing different functional groups, including electron-donating substituents, neutral electron substituents and electron-withdrawing substituents, all showed good reactivity in the reductive methylation reaction with methanol; for nitrobenzene containing halogens (F, Cl), no dehalogenation phenomenon occurred. 1.5 / ZnO catalyst has good substrate universality.

[0085] Example 8

[0086] 0.3wt% IrIn 1.5 The / ZnO catalyst was repeatedly used in the reductive methylation reaction system of nitrobenzene to test the stability and reusability of the catalyst. 0.5mmol nitrobenzene, 5mL methanol and freshly prepared 0.3wt% IrIn 1.5 / ZnO catalyst was mixed in a high pressure reactor and reacted at 0.5MPa N2 and 130°C for 5h. After the reaction was completed, the catalyst was filtered and the catalyst and filtrate were collected. The catalyst was washed three times with methanol, then washed three times with dichloromethane, and dried in an oven at 80°C for 5h to obtain the catalyst after the first use. Before the next reaction, the catalyst after the first use was placed in a muffle furnace and calcined at 400°C for 30min, and then reduced at 400°C for 2h in a 10vol% H2 / Ar atmosphere. Then the above experimental process was repeated 5 times, and the product and yield were analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GCMS). The results are shown in Table 8.

[0087] Table 8

[0088]

[0089]

[0090] It can be seen from Table 8 that 0.3wt% IrIn1.5 After the ZnO / ZnO catalyst was reused for 5 times, there was no significant decrease in the catalyst activity and selectivity, indicating that the catalyst has good stability and reusability.

[0091] The present invention adopts an ultrasonic impregnation method to prepare a highly active supported iridium-indium bimetallic catalyst. The ultrasonic action is conducive to the loading of active metals on the surface of the oxide carrier in the form of single atoms or fully exposed nanoclusters, providing abundant active sites for the activation and conversion of methanol. The introduction of the auxiliary metal In can make the Ir species on the catalyst surface present more electron-deficient oxidation states IrO x Active sites, IrO x The interaction with the carrier can effectively catalyze the activation and conversion of methanol. Using methanol as a green hydrocarbon source, the iridium-indium bimetallic catalyst can catalyze the efficient preparation of N,N-dimethylaniline compounds from aromatic nitro compounds in a one-pot process without additives and under mild conditions.

[0092] Compared with the shortcomings and deficiencies of the prior art, the present invention has the following beneficial effects: in the IrIn bimetallic catalyzed aromatic nitro reduction methylation reaction, methanol is simultaneously used as a hydrogen source, a methyl source and a solvent, the activation conversion of methanol is coupled with the nitro reduction methylation, and N,N-dimethylaniline compounds are synthesized in one step without exogenous base conditions, which has the advantages of being clean, efficient, safe, and highly operable. The prepared IrIn catalyst has high metal dispersion, good catalytic activity, selectivity and stability, and after being repeatedly used 5 times in the aromatic nitro reduction methylation reaction, the activity does not decrease significantly, and the substrate has wide applicability, and has good economic value and industrial application prospects.

[0093] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. An application of a supported iridium-indium bimetallic catalyst for reductive methylation of aromatic nitro groups in the reductive methylation of aromatic nitro compounds using methanol as a hydrocarbon source, characterized in that: include, The supported iridium-indium bimetallic catalyst, solvent and aromatic nitro compound are mixed, and the reaction time is 5 to 24 h at 120 to 150 °C, nitrogen pressure of 0.5 MPa and the amount of solvent of 5 to 7 mL; wherein the solvent is methanol; The aromatic nitro compound is selected from p-nitrotoluene, m-nitrotoluene, o-nitrotoluene, p-nitroanisole, o-nitroanisole, m-phenylnitrobenzene, 4-nitrochlorobenzene, 3-nitrochlorobenzene, 3-nitrofluorobenzene, 3-nitrobenzotrifluoride, methyl 4-nitrobenzoate, methyl 3-nitrobenzoate, methyl 3-nitrophenylacetate, methyl 3-nitrophenylpropionate, 2,4-dimethylnitrobenzene, 3,4-dimethylnitrobenzene, 3,5-dimethylnitrobenzene, 2,4-dimethoxynitrobenzene, 3,4-dimethoxynitrobenzene, and 3-nitropyridine; The supported iridium-indium bimetallic catalyst comprises: Carrier; A main active component, wherein the main active component is supported on a carrier in the form of nanoclusters or single atoms; and Auxiliary metal, the auxiliary metal is in close contact with the main active component and is evenly dispersed on the carrier; Wherein, the main active component is Ir; the auxiliary metal is In, and the molar ratio of the main active component to the auxiliary metal is 1:1.5-2.

2. The use according to claim 1, characterized in that: The loading amount of the main active component in the carrier is 0.1-3.0 wt%.

3. The use according to claim 1, characterized in that: The carrier is one of zinc oxide, cerium oxide, titanium oxide, magnesium oxide and zirconium oxide.

4. The use according to any one of claims 1 to 3, characterized in that: The method for preparing the supported iridium-indium bimetallic catalyst for aromatic nitro reduction methylation comprises: The carrier is dispersed in deionized water, and the precursor of the main active component and the precursor of the auxiliary metal are added in sequence, and the catalyst is evaporated by ultrasonic vibration to obtain a supported iridium-indium bimetallic catalyst precursor after drying; The supported iridium-indium bimetallic catalyst precursor was ground and sieved, placed in a reducing atmosphere, and pretreated at 400 °C for 30-120 min to obtain the supported iridium-indium bimetallic catalyst.

5. The use according to claim 4, characterized in that: The precursor of the main active component includes one of chloroiridic acid hydrate, iridium trichloride, iridium acetylacetonate, and iridium acetate; The precursor of the auxiliary metal includes one of indium nitrate hydrate, indium trichloride, indium acetate and indium acetylacetonate.

6. The use according to claim 1, characterized in that: The molar ratio of the main active component in the supported iridium-indium bimetallic catalyst to the aromatic nitro compound is 1:20-1:200.

Images