Intermetallic Compound-Supported Zirconium Carbide

Abstract

As a catalyst for realizing high palladium dispersity and a stable, electron-rich palladium site, there is provided a catalyst in which particles of an intermetallic compound of palladium and zirconium are supported on zirconium carbide having a nanoporous structure.

Description

[Technical Field]

[0001] The present invention relates to a novel intermetallic compound-supported zirconium carbide. Palladium contained in this material is dispersed on the zirconium carbide and is electron-rich and stable. Therefore, this material functions as a solid catalyst with high activity and stability. [Background technology]

[0002] The Suzuki coupling, an important reaction for creating C-C bonds in organic synthesis, was originally performed using homogeneous palladium catalysts. Specific catalysts known include Pd(OAc)2, Pd(PPh3)4, and Pd(dtbpf)Cl2 (Miyaura N. and Suzuki A., Chem. Rev. 95, 2457-2483 (1995)). Heterogeneous catalysts, on the other hand, offer cost and environmental advantages because they do not require ligands and the palladium catalyst can be recovered. Metal-supported catalysts, in which palladium is supported on a support (carbon or metal oxide), are a typical heterogeneous catalyst. However, due to the weak mechanical and electronic interactions between the support and palladium, condensation and desorption of palladium atoms are likely to occur. Furthermore, it is difficult to achieve electron-rich palladium.

[0003] Recently, the present inventors discovered that an intermetallic compound of yttrium and palladium (Y3Pd2) functions as a highly active and stable solid catalyst for Suzuki coupling reactions (Non-Patent Document 1). In this intermetallic compound, the palladium sites are stabilized in the crystal lattice, making condensation and desorption of palladium atoms difficult. Furthermore, the low electronegativity of yttrium keeps the palladium in an electron-rich state. While Y3Pd2 exhibits such excellent catalytic performance, its synthesis requires high-temperature conditions, making it difficult to produce a powder with a high surface area. As a result, the majority of the palladium does not function as a catalyst and is wasted. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Ye, TN et al. Nat. Communi. 10, 5653 (2019) Summary of the Invention [Problem to be solved by the invention]

[0005] In metal-supported catalysts, palladium can be supported on supports with high specific surface areas, such as carbon or oxide nanoparticles, achieving high palladium dispersion. However, the interaction between palladium and the support is weak, resulting in insufficient catalytic activity and stability.

[0006] On the other hand, in intermetallic compounds such as Y3Pd2, palladium forms compounds with elements such as yttrium, creating electron-rich and stable palladium sites, which can significantly improve catalytic activity and stability. However, it is currently difficult to achieve a high surface area, and the majority of palladium atoms are not exposed on the surface, resulting in low palladium efficiency.

[0007] An object of the present invention is to provide a catalyst that combines the advantages of both a supported metal catalyst and an intermetallic compound, that is, a catalyst that realizes high palladium dispersion and electron-rich and stable palladium sites. [Means for solving the problem]

[0008] As a result of extensive investigations aimed at solving the above problems, the present inventors discovered that a catalyst having a high degree of palladium dispersion and electron-rich and stable palladium sites can be obtained by calcining a mixture of a zirconium polymer and palladium acetate at a high temperature, and thus completed the present invention.

[0009] That is, the present invention provides [1] to

[15] . [1] Zirconium carbide supported on an intermetallic compound, characterized in that particles of an intermetallic compound of palladium and zirconium are supported on zirconium carbide having a nanoporous structure.

[0010] [2] The zirconium carbide supported on an intermetallic compound according to [1], characterized in that the intermetallic compound of palladium and zirconium is an intermetallic compound represented by the formula: ZrPd3.

[0011] [3] The zirconium carbide-supported intermetallic compound according to [1] or [2], characterized in that the particles of the intermetallic compound of palladium and zirconium have an average particle size in the range of 1 to 30 nm.

[0012] [4] The specific surface area of ​​nanoporous zirconium carbide is 100m 2 g -1 The intermetallic compound-supported zirconium carbide according to any one of [1] to [3], characterized in that:

[0013] [5] A catalyst comprising the intermetallic compound-supported zirconium carbide according to any one of [1] to [4].

[0014] [6] The catalyst according to [5], which is used in Suzuki coupling reaction, acetylene hydrogenation reaction, or nitrobenzene hydrogenation reaction.

[0015] [7] A method for producing an intermetallic compound-supported zirconium carbide, comprising the following steps (1) and (2): (1) preparing a mixture of a zirconium polymer and a palladium salt; (2) A step of firing the mixture prepared in step (1).

[0016] [8] The method for producing an intermetallic compound-supported zirconium carbide according to [7], wherein step (1) includes the following steps (1-1) and (1-2): (1-1) a step of dissolving a zirconium polymer and a palladium salt in a solvent to obtain a solution; (1-2) A step of drying the solution obtained in the step (1-1) to obtain a mixture of zirconium polymer and palladium salt.

[0017] [9] The method for producing an intermetallic compound-supported zirconium carbide according to [8], characterized in that the solvent is acetone, ethanol, methanol, tetrahydrofuran, or a mixed solvent thereof.

[0018]

[10] The method for producing an intermetallic compound-supported zirconium carbide according to any one of [7] to [9], characterized in that step (2) is a step of firing the mixture prepared in step (1) at 1000 to 2000 ° C.

[0019]

[11] A method for producing an intermetallic compound-supported zirconium carbide according to any one of [7] to [9], characterized in that the zirconium polymer is polyzirconosal.

[0020]

[12] The method for producing an intermetallic compound-supported zirconium carbide according to any one of [7] to

[11] , characterized in that the palladium salt is bis(dibenzylideneacetone)palladium, tris(dibenzylideneacetone)dipalladium, or palladium acetate.

[0021]

[13] A method for producing an optionally substituted biaryl compound, which comprises reacting an optionally substituted aryl halide with an optionally substituted arylboronic acid in an organic solvent in the presence of a base and a catalyst, wherein the catalyst is the catalyst according to [5] or [6].

[0022]

[14] The method for producing a biaryl compound according to

[13] , wherein the optionally substituted aryl halide is an optionally substituted benzene halide.

[0023]

[15] A method for producing a biaryl compound according to

[13] or

[14] , wherein the arylboronic acid which may be substituted with a substituent is a phenylboronic acid which may be substituted with a substituent.

[0024] This specification includes the contents disclosed in the specification and / or drawings of Japanese Patent Application No. 2020-081143, which is a priority document of this application. [Effects of the Invention]

[0025] The present invention provides a novel intermetallic compound-supported zirconium carbide. Palladium contained in this material is dispersed on the zirconium carbide, and is electron-rich and stable. Therefore, this material functions as a solid catalyst with high activity and stability. [Brief explanation of the drawings]

[0026] [Figure 1] Synthesis and nanoporous structure of ZrC. (a) Diagram showing the crystal structure of ZrC, which has a NaCl structure. (b) Schematic diagram of the synthesis of the ZrC precursor (PZSA). (c) Powder X-ray diffraction pattern of the t-ZrO2-C composite after heat treatment (first at 900 °C, then at 1400 °C). (d and e) Scanning transmission electron microscope (STEM) images of ZrO2-C. (f) Diagram showing the structure of the produced ZrO2-C. (g and h) STEM images of ZrC nanoparticles. (i) Diagram showing the nanoporous structure of the produced ZrC nanoparticles. [Figure 2]Formation of intermetallic ZrPd3 nanoparticles on nanoporous ZrC. (a and b) Powder X-ray diffraction patterns of Pd-ZrC composites with different Pd contents. The solid black circles and gray arrows indicate the Bragg peak positions of ZrPd3 and metallic Pd. (c) Scanning transmission electron microscope image of freshly prepared Pd(1 wt%)-ZrC. The formed ZrPd3 phase appears as a bright spot. The right side of (c) shows the crystal structure of ZrPd3. Zr and Pd atoms are depicted as green and gray spheres, respectively. A schematic diagram of the Pd-ZrC structure is also shown at the bottom of (c). (d and e) K-edge X-ray absorption structure of Pd in ​​the ZrPd3 plane and its migration into Pd(1 wt%)-ZrC. The corresponding data for pure Pd and PdO are also reported in the plot as references for Pd0 and Pd2+. [Figure 3] Catalytic activity of Pd-ZrC catalyst. Arrhenius plots for Suzuki cross-coupling reactions performed using (a) iodobenzene and (b) bromobenzene as substrates. Reaction conditions: 5 mg of Pd (1 wt%)-ZrC catalyst, 0.5 mmol of organic halide, 0.8 mmol of phenylboronic acid, 1.5 mmol of K2CO3, and 5 mL of solvent. (c) Comparison of the recyclability of Pd-ZrC with other Pd-based catalysts in Suzuki cross-coupling reactions using iodobenzene as a reactant. In particular, the normalized conversion measured in the presence of catalyst Pd-ZrC after each reaction cycle was compared with that measured in the presence of 1 wt% Pd-loaded ZrC (Pd(1 wt%) / ZrC) and three commercial catalysts: Pd(10 wt%) / C, Pd(5 wt%) / Al2O3, and Lindlar's catalyst. Data on elemental Pd and commercial catalysts are reproduced from Ye, TN et al. Nat. Commun. 10, 5653 (2019). [Figure 4]Diagram depicting the electronic interactions between the catalyst and bromobenzene. (a) Adsorption of bromobenzene on the ZrPd3(0001) surface. The bottom of (a) shows a top-down view of the system and the C-Br bond lengths. (b) Same diagram and data as (a) but for adsorption of bromobenzene on the surface of Pd-ZrC. Zr and Pd atoms are represented as green and gray spheres, respectively. DETAILED DESCRIPTION OF THE INVENTION

[0027] The present invention will be described in detail below. (A) Intermetallic Compound-Supported Zirconium Carbide The intermetallic compound-supported zirconium carbide of the present invention is characterized in that particles of an intermetallic compound of palladium and zirconium are supported on zirconium carbide having a nanoporous structure.

[0028] In the present invention, "zirconium carbide with a nanoporous structure" refers to zirconium carbide with a large number of fine pores with a pore size of nano-order. Since a material with a nanoporous structure has a large specific surface area, it is also possible to define "zirconium carbide with a nanoporous structure" by the specific surface area. For example, a material with a specific surface area of ​​100 m 2 g -1 More than 350m 2 g -1 Over 400m 2 g -1 Over 450m 2 g -1 or more, or 500 m 2 g -1 The above zirconium carbide can also be defined as "zirconium carbide having a nanoporous structure."

[0029] An example of an intermetallic compound of palladium and zirconium is an intermetallic compound represented by ZrPd3.

[0030] The particles of the intermetallic compound of palladium and zirconium are preferably fine particles, because fine particles allow a large amount of palladium to be exposed on the surface. Specifically, the average particle size of the particles of the intermetallic compound of palladium and zirconium is preferably in the range of 1 to 100 nm, more preferably in the range of 1 to 30 nm, and even more preferably in the range of 1 to 10 nm.

[0031] The intermetallic compound-supported zirconium carbide of the present invention can be produced by the method described in the section "(C) Production method" below.

[0032] (B) Catalyst The catalyst of the present invention is characterized by containing an intermetallic compound-supported zirconium carbide. The catalyst of the present invention usually consists of only an intermetallic compound-supported zirconium carbide, but may also contain other substances. As the intermetallic compound-supported zirconium carbide, the above-mentioned intermetallic compound-supported zirconium carbide of the present invention is used.

[0033] The catalyst of the present invention is mainly used in Suzuki coupling reactions, but can also be used in other reactions, such as the hydrogenation of alkynes such as acetylene, and the hydrogenation of nitrobenzene.

[0034] The catalyst of the present invention has the following advantages: 1) The catalyst of the present invention exhibits high activity because ZrPd3 is dispersed on zirconium carbide, which has a large surface area. 2) Palladium forms an intermetallic compound with zirconium, but since zirconium has a lower electronegativity than palladium, the palladium in the intermetallic compound is in an electron-rich state, which allows the catalyst of the present invention to exhibit high activity. 3) A large amount of energy is required for the aggregation and desorption of palladium in the intermetallic compound, which is why the catalyst of the present invention exhibits high stability.

[0035] (C) Manufacturing method The method for producing an intermetallic compound-supported zirconium carbide of the present invention is characterized by comprising the following steps (1) and (2).

[0036] In step (1), a mixture of a zirconium polymer and a palladium salt is prepared. The zirconium polymer is not particularly limited as long as it can be used as a raw material for the highly active and highly stable catalyst described above. For example, polyzirconosaal (PZSA) can be used. Polyzirconosaal is a known compound and can be synthesized, for example, according to the method described in Tao, X. et al. Adv. Appl. Ceram. 112, 301-305 (2012). Polyzirconosaal is typically produced from zirconium oxychloride octahydrate (ZrOCl2·8H2O) and salicyl alcohol. The specific surface area of ​​zirconium carbide produced from polyzirconosaal increases with the amount of salicyl alcohol used. The larger the specific surface area of ​​zirconium carbide, the more exposed palladium atoms become on the surface, resulting in higher palladium efficiency. Therefore, it is preferable to use a larger amount of salicyl alcohol. Normally, with 1g of zirconium oxychloride octahydrate and 0.13g of salicylic alcohol, the specific surface area of ​​zirconium carbide is 100m 2 g -1 Therefore, it is preferable to use a larger amount of salicylic alcohol than this. Specifically, it is preferable to use 0.23 to 0.39 g of salicylic alcohol per 1 g of zirconium oxychloride octahydrate.

[0037] The palladium salt is also not particularly limited as long as it can be used as a raw material for the above-mentioned highly active and highly stable catalyst. For example, an organic palladium salt can be used. Preferably, bis(dibenzylideneacetone)palladium, tris(dibenzylideneacetone)dipalladium, or palladium acetate can be used.

[0038] The mixing ratio of the zirconium polymer and the palladium salt is not particularly limited as long as it is a mixing ratio that allows the production of the above-mentioned highly active and highly stable catalyst, but the mixing ratio is such that the palladium content in the mixture is preferably 0.1 to 10 wt%, more preferably 0.5 to 8 wt%, and even more preferably 1 to 5 wt%.

[0039] The method for preparing the mixture is not particularly limited, but it is preferable to prepare it by a method including the steps of (1-1) dissolving a zirconium polymer and a palladium salt in a solvent to obtain a solution, and (1-2) drying the solution obtained in step (1-1) to obtain a mixture of a zirconium polymer and a palladium salt.

[0040] The solvent used in step (1-1) is not particularly limited as long as it can dissolve both the zirconium polymer and the palladium salt. For example, acetone, ethanol, methanol, tetrahydrofuran, or a mixture thereof can be used.

[0041] In step (2), the mixture prepared in step (1) is fired. The calcination temperature is not particularly limited as long as it is a temperature at which the above-mentioned highly active and highly stable catalyst can be produced, but is preferably 1000 to 2000°C, more preferably 1200 to 1400°C.

[0042] The calcination time is not particularly limited as long as it is a time that allows the production of the above-mentioned highly active and highly stable catalyst, but is preferably 1 to 8 hours, more preferably 2 to 6 hours.

[0043] (D) Method for producing biaryl compounds The method for producing a biaryl compound (an optionally substituted biaryl) of the present invention is a method for producing an optionally substituted biaryl by reacting an optionally substituted aryl halide with an optionally substituted arylboronic acid in an organic solvent in the presence of a base and a catalyst.

[0044] As the catalyst, the above-mentioned catalyst of the present invention is used.

[0045] The aryl halide may be a halogenated benzene, a halogenated naphthalene, etc. The aryl halide may be one that is commonly used in Suzuki coupling reactions, such as iodobenzene, bromobenzene, 1-iodonaphthalene, 1-bromonaphthalene, 2-iodonaphthalene, or 2-bromonaphthalene.

[0046] As the arylboronic acid, phenylboronic acid, 1-naphthylboronic acid, 2-naphthylboronic acid, etc. can be used.

[0047] Examples of the substituent in the optionally substituted aryl halide include a lower alkyl group (e.g., a methyl group, an ethyl group, a propyl group), a lower alkoxy group (e.g., a methoxy group, an ethoxy group, a propoxy group), a halogen atom (e.g., a fluorine atom, a chlorine atom), a hydroxy group, a trifluoromethyl group, an amino group, and a nitro group.

[0048] Examples of the substituent in the optionally substituted arylboronic acid include a lower alkyl group (e.g., a methyl group, an ethyl group, a propyl group), a lower alkoxy group (e.g., a methoxy group, an ethoxy group, a propoxy group), a halogen atom (e.g., a fluorine atom, a chlorine atom), a trifluoromethyl group, and a t-butyl group.

[0049] The base may be any base commonly used in Suzuki coupling reactions, such as potassium carbonate, sodium carbonate, potassium hydroxide, sodium hydroxide, trisodium phosphate, tripotassium phosphate, sodium hydrogen phosphate, potassium hydrogen phosphate, etc.

[0050] The organic solvent is preferably one that does not interfere with the reaction and has high solubility for the raw material compounds used in the reaction.Specific examples that can be used include methanol, ethanol, trifluoroacetic acid, tetrahydrofuran, acetonitrile, N,N-dimethylformamide, benzene, toluene, 1,4-dioxane, dichloromethane, chloroform, and 1,2-dichloroethane.

[0051] The reaction temperature can be appropriately selected depending on the raw material compounds used, but is preferably 10 to 200°C, more preferably 20 to 80°C.

[0052] The reaction time can be appropriately selected depending on the raw material compounds used, but is preferably 5 to 20 hours, more preferably 8 to 16 hours. [Example]

[0053] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. [Results and Discussion] (1) Formation of nanoporous structure in ZrC Figures 1a and 1b show a schematic diagram of the crystal structure of ZrC and the synthetic procedure performed to obtain this support. In this study, PZSA was used as a precursor for ZrC synthesis. When PZSA was calcined at 900 °C under argon flow, it thermally decomposed into tetragonal ZrO2 (t-ZrO2, see Figure 1c). Although no peaks due to carbon compounds were observed in the powder X-ray diffraction (XRD) plot, the resulting powder was black, suggesting the presence of amorphous carbon (Figure 1c). Indeed, scanning transmission electron microscopy (STEM) analysis confirmed the presence of an amorphous carbon phase between t-ZrO2 particles, forming a t-ZrO2-C composite (Figures 1d-f). When the calcination temperature was increased to 1400 °C, the t-ZrO2 was reduced by reaction with carbon, and the composite transformed into ZrC nanoparticles (Figures 1c, g-i).

[0054] The surface area of ​​the obtained ZrC nanoparticles (339 m2 g -1 ) is a simple estimate based on the apparent ZrC grain size (approximately 10 m 2 g -1 ) is much larger than the pore volume of the resulting ZrC nanoparticles. The plots obtained from N2 adsorption / desorption experiments performed on ZrC nanoparticles are characterized by the presence of a clear hysteresis, indicating that structures containing pores with a size of a few nanometers have been produced. Such structures contribute to an increase in the surface area of ​​the material. The pore volume of the resulting ZrC is approximately 0.3 cm. 3 g -1 This corresponds to a porosity value of 67%. The porous structure of the ZrC nanoparticles was revealed by STEM observation, which showed the presence of pores several nanometers in size (Figure 1h). The STEM data also showed that the pore morphology was consistent with that of amorphous carbon present in t-ZrO2-C, leading to the conclusion that the porous structure was generated as a result of the oxidation of carbon and the release of CO and CO2 (Figures 1f and i). The method developed here can also be applied to HfC. However, despite the fact that HfC exhibits nearly identical properties to ZrC, this study focuses on ZrC because Hf is much more expensive than Zr. Although the synthesized ZrC nanoparticles are known to contain residual amorphous carbon, it should be emphasized that the nanoporous structure exists in the ZrC itself, given the lack of hysteresis in the N2 adsorption / desorption curves of the t-ZrO2-C composites.

[0055] (2) Dispersion of ZrPd3 using nanoporous ZrC Due to the high surface area of ​​nanoporous ZrC nanoparticles, PZSA was calcined with palladium acetate. The primary motivation for this method was to obtain a highly dispersed Zr-Pd intermetallic phase in nanoporous ZrC nanoparticles (Pd-ZrC). This is difficult to achieve using conventional solid-state or chemical reduction methods. Figures 2a and 2b show powder X-ray diffraction data for Pd-ZrC prepared with different amounts of Pd. As is evident from the data in these figures, a distinct peak at 2θ = 41.7° can be identified as the amount of Pd in ​​Pd-ZrC increases. This signal is the main (20-20) peak of ZrPd3, and its appearance confirms that intermetallic ZrPd3 has been formed on the surface of ZrC. However, the main peaks due to Pd clusters, which should appear at 2θ = 40.1° (111) and 46.7° (200), could not be identified. This observation indicates that the formation of ZrPd3 intermetallic phases is preferred over the formation of Pd clusters under the synthesis conditions performed. STEM images and energy dispersive X-ray spectroscopy (EDS) analysis results show that ZrPd3 is uniformly dispersed in ZrC, with particle sizes of 2–3 nm (Figure 2c). The as-synthesized Pd-ZrC also exhibits a nanoporous structure, and in the case of Pd (1 wt%)-ZrC, the surface area is 444 m 2 g -1 As expected from the electronegativity gap between Zr(1.33) and Pd(2.20) (Allred, ALJ Inorg. Nucl. Chem. 17, 215-221 (1961)), the Pd atoms are negatively charged, as confirmed by X-ray absorption near edge structure (XANES) data. As is evident from the data reported in Figure 2d and e, the absorption edges of the Pd species in both Pd(1 wt%)-ZrC and ZrPd3 are negatively charged relative to elemental Pd (Pd 0 ) and PdO(Pd 2+ These observations suggest that Zr and Pd are characterized by lower energies than their counterparts in Zr 1.2+ and Pd 0.4- This is consistent with the results of the Bader analysis, which calculated that

[0056] (3) Application of Suzuki cross-coupling to catalysis ZrC is a metallic material, and its work function (Φ WF =3.7 eV) (Wilson, RG and McKee WEJ Appl. Phys. 38, 1716 (1967)) is WF = 4.7 eV). Considering that ZrC and the intermetallic ZrPd species are metallic and in electronic contact, this property, together with the negatively charged Pd active sites, should promote the electron-donating ability of Pd-ZrC. Furthermore, the large surface area of ​​the nanoporous structure of Pd-ZrC should increase the number of exposed Pd sites, improving the Pd atom economy of the material. Therefore, there was motivation to investigate the use of Pd-ZrC as a catalyst for the Suzuki cross-coupling reaction. In detail, when iodobenzene and phenylboronic acid were used as substrates, Pd (1 wt%)-ZrC exhibited high catalytic performance, with a reaction rate of 7.3 mmol g−1 measured at room temperature (25 °C). -1 h -1 Based on the amount of exposed Pd sites in Pd (1 wt%)-ZrC, the TOF value of the above reaction was 2943 h -1It was estimated that... This TOF value is consistent with the reaction conditions used in the case of Pd(1wt%)-ZrC, as reported in the literature (Zhu, M. and Diao, GJ Phys. Chem. C 115, 24743-24749 (2011) ; Zhang, A. et al. J. Mater. Chem. A 2 ,1369-1374 (2014) ; Jiang, Y. et al. Phys. Chem. Chem. Phys. 13, 2512-2516 (2011) ; Shylesh, S. Wang, L. Demeshko, S. and Thiel, WR ChemCatChem 2, 1543-1547 (2010) ; Yuan, H. Liu, H. Zhang, B. Zhang, L. Wang, H. and Su, DS Phys. Chem. Chem. Phys. 16,11178-11181 (2014), Zhang, P. Weng, Z. Guo, J. and Wang, C. Chem. Mater. 23, 5243-5249 (2011), Cargnello, M. et al. Chem. Mater. 23, 3961-3969 (2011), Kim, E., Jeong, HS and Kim, BM Catal. Commun. 46, 71-74 (2014), Roy, AS et al. Appl. Catal. A 469, 320-327 (2014), Borhade, SR and Waghmode, SB Beilstein J. Org. Chem. 7, 310-319 (2011), Camp, JE et al. ACS Sustainable Chem. Eng. 2, 500-505 (2014); Song, HQ; Zhu, Q.; Zheng, X.; and Chen, XG. J. Mater. Chem. A 3, 10368-10377 (2015)). However, this is still several orders of magnitude higher than the corresponding values ​​reported for previously investigated metal-supported catalysts. For comparison, we also tested the catalytic performance of ZrPd powder.Based on the amount of Pd sites exposed on the surface, the estimated TOF value for ZrPd3 is 2235 h. -1 This is comparable to the calculated value for Pd(1 wt%)-ZrC and far exceeds that reported for conventional Pd-supported catalysts. Suzuki cross-coupling reactions were also performed using bromobenzene and phenylboronic acid as substrates. Because C-Br has a stronger bond than CI, the cross-coupling must be carried out at a higher temperature (60 °C), and in this case the reaction rate was 9.3 mmol g -1 h -1 In this reaction, the Pd-ZrC catalyst showed a lower activation barrier than Pd metal (Figure 3a and b). The apparent activation energies for the cross-coupling reaction catalyzed by Pd (1 wt%)-ZrC and those containing iodobenzene or bromobenzene as substrates were 53 and 64 kJmol, respectively. -1 These values ​​are 28% and 40% smaller than those for Pd. These differences explain why the Pd (1 wt%)-ZrC catalyzed reaction proceeded under milder conditions than the analogous reaction catalyzed by metallic Pd. Because the oxidative addition of aryl halides is considered the rate-limiting step in Suzuki cross-coupling reactions (Wang, F. et al. J. Am. Chem. Soc. 135, 5588-5601 (2013); Zhang, X. et al. J. Am. Chem. Soc. 140, 954-962 (2018)), these associated lower activation barriers can be attributed to the weakening of the CX (X = I, Br) bond, achieved as a result of the strong electron-donating ability of Pd-ZrC. This will be discussed in more detail in the next section.

[0057] In addition to its high catalytic performance, a notable advantageous property of Pd-ZrC is its stability over multiple reaction cycles. As evident from the data in Figure 3c, the Pd-ZrC catalyst could be recycled 15 times, significantly outperforming Pd-loaded ZrC (Pd / ZrC) and other Pd-based commercially available heterogeneous catalysts (e.g., Pd / C, Pd / Al2O3, and Pb-Pd (5 wt%) / CaCO3 (Lindlar catalyst)). In fact, for these competing catalysts, the catalytic activity for the Suzuki cross-coupling reaction begins to decline within seven cycles. This degradation may be due to weak interactions between the active Pd species and the support, resulting in leaching and / or aggregation of Pd sites. In contrast, in Pd-ZrC, the active Pd sites are anchored in the ZrPd3 crystal lattice. Furthermore, the island formation energy of ZrPd3 was calculated to be 2.07 eV, a value large enough to prevent aggregation. Overall, these properties contribute to the excellent catalytic durability of Pd-ZrC compared to the other catalysts considered. In fact, based on CO pulse chemisorption measurements, we confirmed that the amount of exposed Pd sites remains almost unchanged after catalytic reactions. That is, the amount of adsorbed CO was 0.28 mL g for the fresh catalyst. -1 , 0.23 mL g used -1 STEM analysis of the Pd-ZrC catalyst used revealed that the size of the ZrPd particles remained almost unchanged after the Pd-ZrC was used. Furthermore, based on the results of inductively coupled plasma (ICP) spectroscopy, the concentration of Pd in ​​the reaction solvent was lower than the detection limit (<0.007 ppm). All data on the Pd-ZrC used confirm the robustness of the Pd active sites against leaching and agglomeration, confirming the rationale for the improved catalyst stability.

[0058] One of the key features of Pd-ZrC that functions as a catalyst in Suzuki cross-coupling reactions is the electron transfer effect to the substrate. Figure 4 shows the adsorption of bromobenzene onto the surfaces of ZrPd3 and Pd-ZrC. The ZrPd3 (0001) plane was used in our model because it exhibits the lowest surface energy among the major planes of ZrPd3. As the reactant approaches the ZrPd3 (0001) plane, electron transfer from ZrPd3 to bromobenzene is confirmed, increasing the negative charge of the bromine and carbon atoms. Bader charge analysis results show a 0.05e - The electron of C-Xσ is transferred to bromobenzene. Since aryl halides have an electron gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO), the transferred electron must be accommodated in the LUMO of the aryl halide. This is the C-Xσ * orbitals (Weiss, R. Schwab, O. and Hampel, F. Chem. Eur. J. 5, 968-974 (1999)). As a result, the C-Br bond length is elongated by 2.1% as a result of adsorption (Figure 4a). When ZrPd3 species are generated on ZrC, the electron transfer effect can be enhanced. The results of Bader charge analysis show that more electrons (0.11e - ) is transferred to bromobenzene, and the Y3Pd2 catalyst (0.13e - ) (Ye, TN et al. Nat. Commun. 10, 5653 (2019)). Therefore, in the case of the Pd-ZrC catalyst, the C-Br bond length was further increased, explaining the suppressed activation energy of the Suzuki coupling reaction over the Pd-ZrC catalyst (Figure 4b).

[0059] The presence of strong electron-donating ability indicates that Pd-ZrC undergoes a similar reaction mechanism to the Y3Pd2 catalyst in the Suzuki coupling reaction. That is, the negatively charged Pd stabilized by the intermetallic lattice enhances catalytic activity and stability. However, unlike Y3Pd2, in Pd-ZrC, nanometer-sized ZrPd3 particles are dispersed on the surface of nanoporous ZrC, allowing for more exposed Pd sites. The TOF of Pd(1 wt%)-ZrC is similar to that of Y3Pd2 when only the exposed Pd is considered, but it is several orders of magnitude larger when all Pd sites are considered. In particular, the presence of negative charges on the Pd sites as well as the low work function of ZrC enhance the catalytic activity. The surface TOF value of Pd(1 wt%)-ZrC is 32% larger than that of ZrPd3 powder. ZrC(Φ WF =3.7 eV) (Wilson, RG and McKee WEJ Appl. Phys. 38, 1716 (1967)) and the work function of ZrPd3 (Φ WF = 4.7 eV), the catalytic activity can be further enhanced by electron donation from the catalyst to the substrate, a conclusion consistent with the results of density functional theory (DFT) analysis (see Figure 4). Importantly, the general trends described for the effectiveness of different catalysts are also supported by the trends in activation energy values. The activation energy for the Suzuki cross-coupling reaction of iodobenzene is 53 kJ / mol on Pd-ZrC. -1 , 66 kJmol on the ZrPd3 plane -1 , 74 kJmol for Pd metal -1 This further emphasizes the importance of both the negatively charged Pd sites and the interaction of ZrPd3 with ZrC.

[0060] (4) Application to catalysis of acetylene hydrogenation reaction Pd-ZrC can also be used in the hydrogenation of acetylene. When acetylene and hydrogen gas are passed through Pd(1 wt%)-ZrC as a catalyst, the conversion to ethane begins at room temperature, and at 38 °C, almost all of the acetylene is converted to ethane.

[0061] In summary, we successfully synthesized nanoporous ZrC and demonstrated that the intermetallic ZrPd3 on its surface, generated by the reaction, functions as an efficient and stable catalyst for Suzuki cross-coupling reactions. During calcination, the PZSA precursor first transforms into a t-ZrO2-C composite, and an amorphous carbon phase separates from the t-ZrO2 phase. Subsequently, COx emissions are carried out at 1400 °C, resulting in the transformation of t-ZrO2-C into ZrC, which features a porous structure with pores several nanometers in diameter. By sintering PZSA and palladium acetate together, a several-nanometer-sized intermetallic ZrPd3 phase is observed to grow on the surface of nanoporous ZrC nanoparticles, resulting in the formation of a high-surface-area Pd-ZrC catalyst. The catalyst's negatively charged Pd and low work function allow Suzuki coupling to proceed under mild conditions, and the measured TOF values ​​exceed those reported for conventional Pd-loaded catalysts. Furthermore, because the Pd sites are stabilized within the ZrPd3 crystal lattice framework, Pd-ZrC does not show significant degradation even after up to 15 catalytic cycles. The excellent stability and catalytic activity of this material, along with its economy of Pd atoms, make Pd-ZrC stand out among heterogeneous catalysts for Suzuki cross-coupling reactions. The results of this study emphasize the importance of combining intermetallic catalysts with supports as a way to achieve the goal of improving multiple catalysts. Furthermore, this catalyst is applicable not only to Suzuki coupling but also to hydrogenation reactions.

[0062] Example 1 (1) Synthesis of PZSA (polyzirconosaal) The zirconium polymer PZSA was synthesized according to the method described by Tao, X. et al. Adv. Appl. Ceram. 112, 301-305 (2012). 6.40 g of ZrOCl 2·8H2O and 1.55g of salicylic alcohol were dissolved in 100mL of methanol and cooled to 3°C. 2.0g of acetylacetone and 4.0g of triethyl ether were then added dropwise, and the mixture was allowed to return to room temperature. The mixture was stirred at room temperature for 4 hours, and the methanol was evaporated to yield a white powder. This powder was then added to 50mL of THF, and the impurities were filtered off to yield a THF solution containing PZSA. The THF was then evaporated to yield a pale yellow PZSA powder.

[0063] (2) Synthesis of ZrC ZrC was synthesized by firing the PZSA obtained by the above method at 1400°C for 4 hours under an argon stream.

[0064] (3) Synthesis of Pd-ZrC PZSA and Pd acetate were dissolved in acetone. The acetone solution was stirred for 1 hour, and then the solvent was completely evaporated at 100°C. The resulting powder was then calcined at 1400°C for 4 hours under an argon stream to obtain Pd-ZrC.

[0065] (4) Sample evaluation The Pd-ZrC catalyst synthesized by the above method was evaluated using powder X-ray diffraction. For powder X-ray diffraction, a Bruker D8-ADVANCE (CuKa) ray was used. The data obtained showed that ZrC was synthesized in a single phase and that ZrPd3 was produced. For nitrogen adsorption and desorption, a BELSORP-mini II from BEL was used. Specifically, the sample was cooled to -196°C, and the surface area and pore area were calculated from the number of nitrogen molecules adsorbed on the surface by controlling the nitrogen partial pressure.

[0066] (5) Suzuki coupling reaction conditions The Suzuki coupling reaction using a Pd-ZrC catalyst is a method for producing biphenyl compounds by combining aryl halides with phenylboronic acid and potassium carbonate in an organic solvent. The reaction format is represented as R1-X + R2-B(OH)2 → R1-R2, and the resulting biphenyl compound is obtained by drying the solvent. The specific Suzuki coupling reaction was performed under the standard conditions shown below. 0.05 mmol of aryl halide, 0.08 mmol of phenylboronic acid, 1.5 mmol of potassium carbonate, and 5 mg of Pd-ZrC catalyst were placed in an autoclave along with 5 mL of methanol solution, and the reaction was carried out at temperatures ranging from 25 to 60°C. The purity and yield of the resulting product were evaluated by gas chromatography.

[0067] Example 1-1: 0.05 mmol of iodotoluene, 0.08 mmol of phenylboronic acid, 1.5 mmol of potassium carbonate, and 5 mg of Pd-ZrC catalyst were placed in an autoclave together with 5 mL of a solution (methanol), and the reaction was carried out at 25° C. The reaction time and yield were 9 hours and 94%, respectively.

[0068] Example 1-2: 0.05 mmol of 1-fluoro-4-iodobenzene, 0.08 mmol of phenylboronic acid, 1.5 mmol of potassium carbonate, and 5 mg of Pd—ZrC catalyst were placed in an autoclave together with 5 mL of a solution (methanol), and the reaction was carried out at 25° C. The reaction time and yield were 14 hours and 96%, respectively.

[0069] Example 1-3: 0.05 mmol of 4-iodoanisole, 0.08 mmol of phenylboronic acid, 1.5 mmol of potassium carbonate, and 5 mg of Pd-ZrC catalyst were placed in an autoclave together with 5 mL of a solution (methanol), and the reaction was carried out at 25° C. The reaction time and yield were 12 hours and 92%, respectively.

[0070] Example 1-4: 0.05 mmol of 4-bromotoluene, 0.08 mmol of phenylboronic acid, 1.5 mmol of potassium carbonate, and 5 mg of Pd-ZrC catalyst were placed in an autoclave together with 5 mL of a solution (methanol), and the reaction was carried out at 60° C. The reaction time and yield were 10 hours and 96%, respectively.

[0071] Example 1-5: 0.05 mmol of 4-bromofluorobenzene, 0.08 mmol of phenylboronic acid, 1.5 mmol of potassium carbonate, and 5 mg of Pd-ZrC catalyst were placed in an autoclave together with 5 mL of a solution (methanol), and the reaction was carried out at 60° C. The reaction time and yield were 14 hours and 91%, respectively.

[0072] Example 1-6: 0.05 mmol of 4-bromoanisole, 0.08 mmol of phenylboronic acid, 1.5 mmol of potassium carbonate, and 5 mg of Pd-ZrC catalyst were placed in an autoclave together with 5 mL of a solution (methanol), and the reaction was carried out at 60° C. The reaction time and yield were 16 hours and 87%, respectively.

[0073] Example 1-7: 0.05 mmol of iodobenzene, 0.08 mmol of 4-methylphenylboronic acid, 1.5 mmol of potassium carbonate, and 5 mg of Pd-ZrC catalyst were placed in an autoclave together with 5 mL of a solution (methanol), and the reaction was carried out at 25° C. The reaction time and yield were 8 hours and 97%, respectively.

[0074] Example 1-8: 0.05 mmol of iodobenzene, 0.08 mmol of 4-fluorophenylboronic acid, 1.5 mmol of potassium carbonate, and 5 mg of Pd-ZrC catalyst were placed in an autoclave together with 5 mL of a solution (methanol), and the reaction was carried out at 25° C. The reaction time and yield were 10 hours and 98%, respectively.

[0075] Example 1-9: 0.05 mmol of iodobenzene, 0.08 mmol of 4-methoxyphenylboronic acid, 1.5 mmol of potassium carbonate, and 5 mg of Pd-ZrC catalyst were placed in an autoclave together with 5 mL of a solution (methanol), and the reaction was carried out at 25° C. The reaction time and yield were 16 hours and 86%, respectively.

[0076] Example 1-10: 0.05 mmol of bromobenzene, 0.08 mmol of 4-methylphenylboronic acid, 1.5 mmol of potassium carbonate, and 5 mg of Pd-ZrC catalyst were placed in an autoclave together with 5 mL of a solution (methanol), and the reaction was carried out at 60° C. The reaction time and yield were 10 hours and 97%, respectively.

[0077] Example 1-11: 0.05 mmol of bromobenzene, 0.08 mmol of 4-fluorophenylboronic acid, 1.5 mmol of potassium carbonate, and 5 mg of Pd-ZrC catalyst were placed in an autoclave together with 5 mL of a solution (methanol), and the reaction was carried out at 60° C. The reaction time and yield were 8 hours and 93%, respectively.

[0078] Example 1-12: 0.05 mmol of bromobenzene, 0.08 mmol of 4-methoxyphenylboronic acid, 1.5 mmol of potassium carbonate, and 5 mg of Pd-ZrC catalyst were placed in an autoclave together with 5 mL of a solution (methanol), and the reaction was carried out at 25° C. The reaction time and yield were 12 hours and 92%, respectively.

[0079] (6) Reaction conditions for hydrogenation reaction The reaction described below is the hydrogenation of acetylene to ethane. The reaction was carried out by mixing acetylene and hydrogen with helium gas and passing the mixture through a Pd-ZrC catalyst housed in quartz glass. The gas flow rates were acetylene (0.3 mL / min), hydrogen (3 mL / min), and helium gas (5.7 mL / min), respectively.

[0080] Example 1-13: 30 mg of Pd-ZrC catalyst was placed in a quartz glass, and the reaction was carried out under the above conditions at 25° C. The acetylene conversion efficiency was 19%.

[0081] Example 1-14: 30 mg of Pd-ZrC catalyst was placed in a quartz glass, and the reaction was carried out under the above conditions at 32° C. The acetylene conversion efficiency was 25%.

[0082] Example 1-15: 30 mg of Pd-ZrC catalyst was placed in a quartz glass tube, and the reaction was carried out under the above conditions at 38° C. The acetylene conversion efficiency was 78%.

[0083] Example 1-16: 30 mg of Pd-ZrC catalyst was placed in a quartz glass tube, and the reaction was carried out under the above conditions at 38° C. The acetylene conversion efficiency was 99%.

[0084] Example 2 (1) Synthesis of PZO (Polyzirconoxane) The zirconium polymer PZO was synthesized according to the method described by Tao, X. et al. Adv. Appl. Ceram. 112, 301-305 (2012). 6.40 g of ZrOCl2·8H2O was dissolved in 100 mL of methanol and the solution was cooled to 3 °C. 2.0 g of acetylacetone and 4.0 g of triethyl ether were then added dropwise, and the mixture was allowed to warm to room temperature. The mixture was stirred at room temperature for 4 hours, and the methanol was evaporated to obtain a white powder. This powder was then added to 50 mL of THF, and the impurities were filtered off to obtain a THF solution containing PZO. The carbon content of the resulting Zr polymer was between 10 and 25 wt%.

[0085] (2) Synthesis of PZSA (polyzirconosaal) and PZO-PZSA mixtures The zirconium polymer PZSA was synthesized according to the method described by Tao, X. et al. Adv. Appl. Ceram. 112, 301-305 (2012). 6.40 g of ZrOCl2·8H2O and 0.8 to 2.5 g of salicylic alcohol were dissolved in 100 mL of methanol and cooled to 3 °C. 2.0 g of acetylacetone and 4.0 g of triethyl ether were then added dropwise, and the mixture was allowed to warm to room temperature. The mixture was stirred at room temperature for 4 hours, after which the methanol was evaporated to yield a white powder. This powder was then added to 50 mL of THF, and the impurities were filtered off to obtain a THF solution containing the desired product. The THF was then evaporated to yield a pale yellow zirconium polymer powder. The amount of salicylic alcohol was controllable and could be adjusted to any range from 0.5 g to 2.5 g. In this case, the product is PZSA or a mixture of PZSA and PZO, and the carbon content is 10% by weight or more and 40% by weight or less.

[0086] (3) Synthesis of ZrC ZrC was synthesized by firing the PZSA obtained by the above method at 1400°C for 4 hours under an argon atmosphere. The specific surface area of ​​the obtained ZrC depends on the amount of salicylic alcohol. As shown in the table below, the specific surface area of ​​the obtained ZrC is 50 m 2 / g to 450 m 2 / g range. [Table 1]

[0087] (4) Synthesis of Pd-ZrC Pd-ZrC was obtained by dissolving PZSA or a mixture of PZSA and PZO and Pd acetate in acetone. The acetone solution was stirred for 1 hour, and then the solvent was completely evaporated at 100°C. The resulting powder was then calcined at 1400°C for 4 hours under an argon stream to obtain Pd-ZrC.

[0088] (5) Suzuki coupling reaction conditions Suzuki coupling was carried out under the same conditions as in Example 1.

[0089] Example 2-1: 0.05 mmol of 4-iodophenol, 0.08 mmol of phenylboronic acid, 1.5 mmol of potassium carbonate, and 5 mg of Pd-ZrC catalyst were placed in an autoclave together with 5 mL of a solution (methanol), and the reaction was carried out at 25° C. The reaction time and yield were 18 hours and 91%, respectively.

[0090] Example 2-2: 0.05 mmol of 4-iodobenzofluoride, 0.08 mmol of phenylboronic acid, 1.5 mmol of potassium carbonate, and 5 mg of Pd—ZrC catalyst were placed in an autoclave together with 5 mL of a solution (methanol), and the reaction was carried out at 25° C. The reaction time and yield were 20 hours and 99%, respectively.

[0091] Example 2-3: 0.05 mmol of 4-iodoaniline, 0.08 mmol of phenylboronic acid, 1.5 mmol of potassium carbonate, and 5 mg of Pd-ZrC catalyst were placed in an autoclave together with 5 mL of a solution (methanol), and the reaction was carried out at 25° C. The reaction time and yield were 24 hours and 86%, respectively.

[0092] Example 2-4: 0.05 mmol of 2-iodonaphthalene, 0.08 mmol of phenylboronic acid, 1.5 mmol of potassium carbonate, and 5 mg of Pd-ZrC catalyst were placed in an autoclave together with 5 mL of a solution (methanol), and the reaction was carried out at 25° C. The reaction time and yield were 20 hours and 90%, respectively.

[0093] Example 2-5: 0.05 mmol of 4-bromophenol, 0.08 mmol of phenylboronic acid, 1.5 mmol of potassium carbonate, and 5 mg of Pd-ZrC catalyst were placed in an autoclave together with 5 mL of a solution (methanol), and the reaction was carried out at 60° C. The reaction time and yield were 18 hours and 95%, respectively.

[0094] Example 2-6: 0.05 mmol of 4-bromobenzofluoride, 0.08 mmol of phenylboronic acid, 1.5 mmol of potassium carbonate, and 5 mg of Pd-ZrC catalyst were placed in an autoclave together with 5 mL of a solution (methanol), and the reaction was carried out at 60° C. The reaction time and yield were 22 hours and 89%, respectively.

[0095] Example 2-7: 0.05 mmol of 4-bromoaniline, 0.08 mmol of phenylboronic acid, 1.5 mmol of potassium carbonate, and 5 mg of Pd-ZrC catalyst were placed in an autoclave together with 5 mL of a solution (methanol), and the reaction was carried out at 60° C. The reaction time and yield were 24 hours and 85%, respectively.

[0096] Example 2-8: 0.05 mmol of 4-bromonitrobenzene, 0.08 mmol of phenylboronic acid, 1.5 mmol of potassium carbonate, and 5 mg of Pd-ZrC catalyst were placed in an autoclave together with 5 mL of a solution (methanol), and the reaction was carried out at 60° C. The reaction time and yield were 14 hours and 95%, respectively.

[0097] Example 2-9: 0.05 mmol of 2-bromonaphthalene, 0.08 mmol of phenylboronic acid, 1.5 mmol of potassium carbonate, and 5 mg of Pd-ZrC catalyst were placed in an autoclave together with 5 mL of a solution (methanol), and the reaction was carried out at 60° C. The reaction time and yield were 24 hours and 89%, respectively.

[0098] Example 2-10: 0.05 mmol of iodobenzene, 0.08 mmol of 4-trifluoromethylphenylboronic acid, 1.5 mmol of potassium carbonate, and 5 mg of Pd-ZrC catalyst were placed in an autoclave together with 5 mL of a solution (methanol), and the reaction was carried out at 25° C. The reaction time and yield were 24 hours and 91%, respectively.

[0099] Example 2-11: 0.05 mmol of iodobenzene, 0.08 mmol of 4-t-butylphenylboronic acid, 1.5 mmol of potassium carbonate, and 5 mg of Pd—ZrC catalyst were placed in an autoclave together with 5 mL of a solution (methanol), and the reaction was carried out at 25° C. The reaction time and yield were 20 hours and 97%, respectively.

[0100] Example 2-12: 0.05 mmol of bromobenzene, 0.08 mmol of 4-trifluoromethylphenylboronic acid, 1.5 mmol of potassium carbonate, and 5 mg of Pd-ZrC catalyst were placed in an autoclave together with 5 mL of a solution (methanol), and the reaction was carried out at 60° C. The reaction time and yield were 17 hours and 95%, respectively.

[0101] Example 2-13: 0.05 mmol of bromobenzene, 0.08 mmol of 4-t-butylphenylboronic acid, 1.5 mmol of potassium carbonate, and 5 mg of Pd-ZrC catalyst were placed in an autoclave together with 5 mL of a solution (methanol), and the reaction was carried out at 60° C. The reaction time and yield were 24 hours and 85%, respectively.

[0102] (6) Reaction conditions for nitrobenzene hydrogenation The following describes a method for converting nitrobenzene and its derivatives to the corresponding aniline derivatives. The nitrobenzene derivative (0.5 mmol), hydrogen gas (pressure 60 bar), Pd-ZrC catalyst (5 mg), and solvent (ethanol 5 mL) were sealed in a quartz reactor and the reaction was carried out at room temperature (25 °C).

[0103] Example 2-14: Nitrobenzene was used as the reactant under the above conditions, and the reaction was completed in 17 hours with a yield of 99%.

[0104] Example 2-15: Using 4-methylnitrobenzene as a reactant, the reaction was carried out under the above conditions and completed in 12 hours with a yield of 99%.

[0105] Example 2-16: Using 4-fluoronitrobenzene as a reactant, the reaction was carried out under the above conditions and completed in 12 hours with a yield of 92%.

[0106] Example 2-17: Using 4-nitrobenzotrifluoride as a reactant, the reaction was carried out under the above conditions and completed in 12 hours with a yield of 91%.

[0107] Example 2-18: Using 4-nitroanisole as a reactant, the reaction was carried out under the above conditions and completed in 12 hours with a yield of 99%.

[0108] Example 2-19: Using 4-nitroacetophenone as a reactant, the reaction was carried out under the above conditions and completed in 12 hours with a yield of 95%.

[0109] Example 2-20: Using methyl 4-nitrobenzoate as a reactant under the above conditions, the reaction was completed in 12 hours with a yield of 98%.

[0110] All publications, patents, and patent applications cited herein are hereby incorporated by reference in their entirety. [Industrial Applicability]

[0111] The substance of the present invention functions as a catalyst for Suzuki coupling and hydrogenation reactions, and can therefore be used in the industrial synthesis of biphenyl derivatives, saturated compounds, and the like.

Claims

1. An intermetallic compound-supported zirconium carbide, characterized in that particles of an intermetallic compound represented by the formula: ZrPd 3 are supported on zirconium carbide having a nanoporous structure.

2. The zirconium carbide-supported intermetallic compound according to claim 1, wherein the particles of the intermetallic compound represented by the formula ZrPd 3 have an average particle size in the range of 1 to 30 nm.

3. The specific surface area of ​​nanoporous zirconium carbide is 100m 2 g -1 3. The intermetallic compound-supported zirconium carbide according to claim 1, wherein the intermetallic compound-supported zirconium carbide is selected from the group consisting of carbides, ...

4. A catalyst comprising the intermetallic compound-supported zirconium carbide according to any one of claims 1 to 3.

5. The catalyst according to claim 4, which is used in a Suzuki coupling reaction, an acetylene hydrogenation reaction, or a nitrobenzene hydrogenation reaction.

6. A method for producing an intermetallic compound-supported zirconium carbide, comprising the following steps (1) and (2), wherein the intermetallic compound is an intermetallic compound represented by the formula: ZrPd 3 ; (1) preparing a mixture of a zirconium polymer and a palladium salt; (2) A step of firing the mixture prepared in step (1) at 1000 to 2000°C.

7. The method for producing an intermetallic compound-supported zirconium carbide according to claim 6, wherein the step (1) comprises the following steps (1-1) and (1-2): (1-1) a step of dissolving a zirconium polymer and a palladium salt in a solvent to obtain a solution; (1-2) A step of drying the solution obtained in the step (1-1) to obtain a mixture of zirconium polymer and palladium salt.

8. 8. The method for producing an intermetallic compound-supported zirconium carbide according to claim 7, wherein the solvent is acetone, ethanol, methanol, tetrahydrofuran, or a mixture thereof.

9. 9. The method for producing an intermetallic compound-supported zirconium carbide according to claim 6, wherein the zirconium polymer is polyzirconosal.

10. 10. The method for producing an intermetallic compound-supported zirconium carbide according to claim 6, wherein the palladium salt is bis(dibenzylideneacetone)palladium, tris(dibenzylideneacetone)dipalladium, or palladium acetate.

11. 6. A method for producing an optionally substituted biaryl compound, comprising reacting an optionally substituted aryl halide with an optionally substituted arylboronic acid in an organic solvent in the presence of a base and a catalyst, wherein the catalyst is the catalyst according to claim 4 or 5.

12. 12. The method for producing a biaryl compound according to claim 11, wherein the optionally substituted aryl halide is an optionally substituted benzene halide.

13. 13. The method for producing a biaryl compound according to claim 11 or 12, wherein the arylboronic acid which may be substituted with a substituent is a phenylboronic acid which may be substituted with a substituent.

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