Immobilized complex catalyst and method for producing same

Abstract

The present invention provides an immobilized complex catalyst that has high catalytic activity and that is capable of maintaining the catalytic activity.　This immobilized complex catalyst comprises a support and a complex catalyst which are bound together via a linker moiety. The support and the complex catalyst are bound together via the linker moiety in a manner indicated in formula (1) and / or formula (2), and the complex catalyst and the linker moiety are bound together via an amine linkage.　[In formulas (1) and (2), LpMk represents the complex catalyst which is bound to the linker moiety, and the portion other than LpMk represents a composite which comprises the linker moiety and the support that are bound together. In the complex catalyst, Lp represents p ligands which are the same or different, Mk represents k metal atoms which are the same or different, and p and k each are an integer of 1 to 4. In the composite, R1 to R6 each independently represent a halogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, a hydroxy group, -O-* (where * represents the support, - represents a bond, and O represents an oxygen atom), or -O-· (where · represents another Si atom in the linker moiety of the same immobilized complex catalyst, or an Si atom in a linker moiety of another immobilized complex catalyst, - represents a bond, and O represents an oxygen atom) (at least one from among R1 to R3 in formula (1) and at least one from among R1 to R6 in formula (2) are -O-* (where * is the support, - represents a bond, and O represents an oxygen atom) in the respective formulas, and have the linker moiety and the support bound thereto), Z1 and Z2 each independently represent an aliphatic group which has a substituent, an aliphatic group which does not have a substituent, an aromatic group which has a substituent, or an aromatic group which does not have a substituent, and Q1 and Q2 are each independently a hydrogen atom, an alkyl group, or a linker moiety or the composite].

Description

Immobilized complex catalyst and method for producing the same

[0001] The present invention relates to an immobilized complex catalyst and a method for producing the immobilized complex catalyst.

[0002] Hydrogen has been attracting attention as a next-generation energy source. In recent years, a method for obtaining high-pressure hydrogen without using a compressor has been reported in which hydrogen and carbon dioxide are obtained by dehydrogenating a hydrogen carrier such as formic acid using an iridium catalyst, and its practical application at hydrogen stations and other facilities that require the supply of high-pressure hydrogen is being considered. For example, Patent Document 1 below discloses that a dehydrogenation catalyst containing, as an active ingredient, an iridium complex having an amino group such as a dimethylamino group, a diethylamino group, or a pyrrolidine group at the para-position (4,4'-position) of a 2,2'-bipyridine ligand or at the 4,7'-position of a 1,10-phenanthroline ligand enables stable dehydrogenation reactions even under high-pressure conditions of 160 MPa.

[0003] Furthermore, Non-Patent Document 1 below discloses an immobilized complex catalyst having high activity for the interconversion of carbon dioxide and hydrogen with formic acid, in which an iridium complex having an imidazoline group is immobilized on the surface of silica particles (Non-Patent Document 1). Non-Patent Document 1 describes a method of modifying the surface of silica particles with (3-glycidyloxypropyl)trimethoxysilane and immobilizing an iridium complex on the surface of the silica particles by reacting the glycidyl group with the imidazoline group. Here, the iridium complex and the silica particle surface are immobilized by a linker moiety containing an ether bond.

[0004] Furthermore, Patent Document 2 below discloses a metal-based immobilized catalyst in which a metal complex is immobilized on an inorganic oxide support via a linker moiety and a ligand. In Patent Document 2, the ligand contains phosphorus or nitrogen, such as a diphenylphosphinoethyl (DPPE) group, and the linker moiety is an alkylene group or the like. Furthermore, the immobilized complex catalyst can be used in the production of carboxylic acids using carbon dioxide or formic acid as a raw material.

[0005] Furthermore, Patent Document 3 listed below discloses an immobilized complex catalyst in which polyethyleneimine is crosslinked with an iridium complex catalyst and uncoordinated bipyridine. Patent Document 3 describes a method in which the complex catalyst is incorporated into polyethyleneimine to make it difficult to be released from the ligand, and even if the complex catalyst is released from the ligand, another ligand takes in the complex catalyst, thereby maintaining activity.

[0006] Japanese Patent No. 7370040 JP 2022-66731 A International Publication No. 2024 / 048775

[0007] Journal of the Japan Petroleum Institute, 60, (4), 194-201 (2017)

[0008] The catalyst disclosed in Patent Document 1 is a homogeneous catalyst that dissolves homogeneously in formic acid and a solvent, which makes it difficult to separate the catalyst from the hydrogen carrier, and makes it difficult to recover and regenerate the catalyst.

[0009] For this reason, direct immobilization of complex catalysts on various supports has been investigated for catalyst recovery and regeneration. The immobilized complex catalyst described in Non-Patent Document 1 is obtained by reacting the imidazoline group of the complex catalyst with a glycidyl group modified on the surface of silica particles, thereby immobilizing the complex on a support (silica particles). Furthermore, the immobilized complex catalyst described in Patent Document 2 is obtained by reacting the DPPE group modified on the surface of the support with a complex, synthesizing a complex having DPPE as a ligand on the support, thereby obtaining a DPPE complex immobilized on the support. Furthermore, the immobilized complex catalyst described in Patent Document 3 is obtained by crosslinking polyethyleneimine with an iridium complex catalyst and uncoordinated bipyridine, thereby immobilizing the complex catalyst on a polyethyleneimine support. However, these methods make it difficult to obtain an immobilized complex catalyst in which the complex catalyst is stably immobilized on a support while retaining catalytic activity, and there is a need for the development of an immobilized complex catalyst that can maintain catalytic activity more stably.

[0010] The present invention has been made in view of the above circumstances, and its technical object is to devise an immobilized complex catalyst that has high catalytic activity and is capable of maintaining the catalytic activity, and a method for producing the immobilized complex catalyst.

[0011] An embodiment of an immobilized complex catalyst that solves the above problems and a method for producing the immobilized complex catalyst will be described below.

[0012] An immobilized complex catalyst according to Aspect 1 of the present invention is an immobilized complex catalyst in which a support and a complex catalyst are bonded via a linker moiety, the support and the complex catalyst being bonded via the linker moiety as shown in the following formula (1) and / or the following formula (2), and the complex catalyst and the linker moiety are bonded via an amine bond:

[0013]

[0014]

[0015] [In the formula (1) and the formula (2), L ｐ M ｋ represents the complex catalyst bound to the linker moiety, and L ｐ M ｋ The portion other than the above represents a complex formed by binding the linker portion to the support, and in the complex catalyst, L ｐ represents p ligands, which may be the same or different; M ｋ represents k metal atoms, which may be the same or different, and p and k are each an integer of 1 to 4; and in the complex, R １ ~R ６ each independently represents a halogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, a hydroxy group, -O-* (* represents the support, - represents a bond, and O represents an oxygen atom), or -O-. (- represents another Si atom in the linker part of the same immobilized complex catalyst, or a Si atom in a linker part of another immobilized complex catalyst, - represents a bond, and O represents an oxygen atom) (provided that R in formula (1) １ ~R ３ and R in the formula (2) １ ~R ６ wherein at least one of the formulas is —O—* (* represents the carrier), and the linker portion and the carrier are bonded together), Z １ and Z ２each independently represents a substituted aliphatic group, an unsubstituted aliphatic group, a substituted aromatic group, or an unsubstituted aromatic group; Q １ and Q ２ are each independently a hydrogen atom, an alkyl group, or a linker portion represented by the following formula (3), or the complex:

[0016]

[0017] [In the formula (3), R ７ ~R ９ each independently represents a halogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, a hydroxy group, -O-* (* represents the support, - represents a bond, and O represents an oxygen atom), or -O-. (- represents another Si atom in the linker portion of the same immobilized complex catalyst, or a Si atom in a linker portion of another immobilized complex catalyst, - represents a bond, and O represents an oxygen atom), and Z ３ represents a substituted aliphatic group, an unsubstituted aliphatic group, a substituted aromatic group, or an unsubstituted aromatic group, and the rightmost bond in formula (3) is bonded to the nitrogen atom in formula (1) or (2).

[0018] The immobilized complex catalyst of Aspect 2 is preferably the same as that of Aspect 1, wherein the complex catalyst comprises, as an active ingredient, a complex catalyst represented by any one of the following formulas (4) to (7) or a salt of the complex catalyst, or an isomer of the complex catalyst represented by any one of the following formulas (4) to (7) or a salt of the isomer:

[0019]

[0020]

[0021]

[0022]

[0023] [In the formulas (4) to (7), M is iridium, rhodium, ruthenium, cobalt, osmium, nickel, iron, palladium, platinum, or gold; among the ligands, L is an aromatic anionic ligand or an aromatic ligand; when L has a substituent, the number of the substituents is 1 or 2 or more; among the other ligands, A １ Is, H ２ O, hydride, formate ion, hydroxide ion, or alkoxide ion; L and A １ In the ligand other than the above, the bond order between the elements forming the ligand is a single bond or a double bond, the heterocycle forming the ligand is an aromatic ring or a non-aromatic ring, and X １ ~X ２８ are each independently a carbon atom, a nitrogen atom, an oxygen atom, or a sulfur atom, and R in the formula (4) １０ ~R １７ , R in the formula (5) １８ ~R ２４ , R in the formula (6) ２５ ~R ３０ and R in the formula (7) ３１ ~R ３４ In each formula, at least one is bonded to the linker portion by an amine bond (provided that X ｉ (i is any one of 14 to 19 and 22 to 24) is a nitrogen atom, the nitrogen atom may form an amine bond with the linker moiety.), R １０ ~R ３５ Among these, those which are not bonded to the linker moiety via an amine bond are each independently a hydrogen atom, an alkyl group, a hydroxy group, an alkoxy group, a nitro group, a halogeno group, a sulfone group, a carboxylic acid group, an amino group, an alkylamino group, a phenyl group, or an adjacent R ｉ (i is 10 to 34) form a ring, and Q ３ is an oxygen atom, a sulfur atom, or a selenium atom, and m and n are each a positive integer or 0 and indicate an ionic valence; [c] ｎ－ is any one of hydroxide ion, sulfate ion, chloride ion, bromide ion, nitrate ion, and hexafluorophosphate ion.

[0024] The immobilized complex catalyst of Aspect 3 is preferably the same as Aspect 1 or Aspect 2, wherein the complex catalyst comprises, as an active ingredient, a complex catalyst represented by any one of the following formulas (8) to (11) or a salt of the complex catalyst, or an isomer of the complex catalyst represented by any one of the following formulas (8) to (11) or a salt of the isomer:

[0025]

[0026]

[0027]

[0028]

[0029] [In the formulas (8) to (11), one of the ligands is a pentamethylcyclopentadienyl ligand, and among the other ligands, A １ Is, H ２ O, hydride, formate ion, hydroxide ion, or alkoxide ion; pentamethylcyclopentadienyl ligand and A １ In the ligand other than the above, the bond order between the elements forming the ligand is a single bond or a double bond, the heterocycle forming the ligand is an aromatic ring or a non-aromatic ring, and X １ ~X ２８ are each independently a carbon atom, a nitrogen atom, an oxygen atom, or a sulfur atom, and R in the formula (8) １０ ~R １７ , R in the formula (9) １８ ~R ２４ , R in the formula (10) ２５ ~R ３０ and R in the formula (11) ３１ ~R ３４ In each formula, at least one is bonded to the linker portion by an amine bond (provided that X ｉ (i is any one of 14 to 16, 17 to 19, and 22 to 24) is a nitrogen atom, the nitrogen atom may form an amine bond with the linker moiety), R １０ ~R ３５Among these, those which are not bonded to the linker moiety via an amine bond are each independently a hydrogen atom, an alkyl group, a hydroxy group, an alkoxy group, a nitro group, a halogeno group, a sulfone group, a carboxylic acid group, an amino group, an alkylamino group, a phenyl group, or an adjacent R ｉ (i is 10 to 34) form a ring, and Q ３ is an oxygen atom, a sulfur atom, or a selenium atom, and m and n are each a positive integer or 0 and indicate an ionic valence; [c] ｎ－ is any one of hydroxide ion, sulfate ion, chloride ion, bromide ion, nitrate ion, and hexafluorophosphate ion.

[0030] The immobilized complex catalyst of Aspect 4 is preferably any one of Aspects 1 to 3, wherein the complex catalyst comprises, as an active ingredient, a complex catalyst represented by any one of the following formulas (12) to (18) or a salt of the complex catalyst, or an isomer of the complex catalyst represented by any one of the following formulas (12) to (18) or a salt of the isomer of the complex catalyst:

[0031]

[0032]

[0033]

[0034]

[0035]

[0036]

[0037]

[0038] [In the formulas (12) to (18), one of the ligands is a pentamethylcyclopentadienyl ligand, and among the other ligands, A １ Is, H ２ O, hydride, formate ion, hydroxide ion, or alkoxide ion; pentamethylcyclopentadienyl ligand and A １ In the ligand other than the above, R １０ ~R １７, R in the formula (13) １８ ~R ２４ , R in the formula (14) １８ and R ２０ ~R ２４ , R in the formula (15) １８ ~R ２４ , R in the formula (16) １８ ~R ２４ , R in the formula (17) ２５ ~R ３０ and R in the formula (18) ２５ ~R ３０ At least one of the R ２２ and R in (17) and (18) above. ２７ and R ２８ is bonded to the linker portion via an amine bond, R ｉ (i is 22, 27, or 28) may be bonded to a nitrogen atom of the five-membered aromatic heterocyclic ring, which may form an amine bond with the linker moiety.), R １０ ~R ３０ Among these, those that are not bonded to the linker portion via an amine bond are each independently a hydrogen atom, an alkyl group, a hydroxy group (—OH), an alkoxy group (—OR), a nitro group, a halogeno group, a sulfone group, a carboxylic acid group, an amino group, an alkylamino group, a phenyl group, or an adjacent R ｉ (i is 10 to 30) form a ring together, m and n are each a positive integer or 0 and indicate an ionic valence, [c] ｎ－ is any one of hydroxide ion, sulfate ion, chloride ion, bromide ion, nitrate ion, and hexafluorophosphate ion.

[0039] The immobilized complex catalyst of Aspect 5 is any one of Aspects 1 to 4, and preferably contains, as an active ingredient, a complex catalyst represented by any one of the following formulas (19) to (22) or a salt of the complex catalyst, or an isomer of the complex catalyst represented by any one of the following formulas (19) to (22) or a salt of the isomer of the complex catalyst:

[0040]

[0041]

[0042]

[0043]

[0044] [In the formulas (19) to (22), one of the ligands is a pentamethylcyclopentadienyl ligand, and among the other ligands, A １ Is, H ２ O, hydride, formate ion, hydroxide ion, or alkoxide ion; pentamethylcyclopentadienyl ligand and A １ In the ligand other than the above, R １２ and R １５ , R in the formula (20) １２ and R １５ , R in the formula (21) １８ , R ２０ , and R ２２ and R in the formula (22) ２７ and R ２８ In each formula, at least one is bonded to the linker portion via an amine bond (provided that R ２２ and R in the formula (22) ２７ and R ２８ is bonded to the linker portion via an amine bond, R ｉ (i is 22, 27, or 28) may be bonded to a nitrogen atom of the five-membered aromatic heterocyclic ring via an amine bond to the linker moiety.), R １２ , R １５ , R １８ , R ２０ , R ２２ , R ２７ , and R ２８ [c], each of the groups not bonded to the linker moiety via an amine bond is independently a hydrogen atom, an alkyl group, a hydroxy group, an alkoxy group, a nitro group, a halogeno group, a sulfone group, a carboxylic acid group, an amino group, an alkylamino group, or a phenyl group, and m and n are each a positive integer or 0 and represent an ionic valence. ｎ－is any one of hydroxide ion, sulfate ion, chloride ion, bromide ion, nitrate ion, and hexafluorophosphate ion.

[0045] The immobilized complex catalyst of Aspect 6 is any one of Aspects 1 to 5, wherein the support preferably has hydroxyl groups on the surface thereof.

[0046] The immobilized complex catalyst of Aspect 7 is any one of Aspects 1 to 6, wherein the support preferably contains any one of porous glass, silica gel, and mesoporous silica.

[0047] The immobilized complex catalyst of Aspect 8 is preferably used as a heterogeneous catalyst in a liquid phase or a gas phase in any one of Aspects 1 to 7.

[0048] The immobilized complex catalyst of Aspect 9 is preferably used in any one of Aspects 1 to 8 for the decomposition of formic acid and the production of hydrogen and / or carbon dioxide.

[0049] An immobilized complex catalyst according to a tenth aspect of the present invention is an immobilized complex catalyst in which a complex catalyst is supported on a carrier, the complex catalyst comprising at least one metal element selected from the group consisting of iridium, rhodium, ruthenium, cobalt, osmium, nickel, iron, palladium, platinum, and gold, and a ligand containing a five-membered ring ligand and / or an amine, and the immobilized complex catalyst exhibits a chromatographically significant peak obtained by solid-state NMR measurement. ２９ In the Si-NMR spectrum, T ３ It is preferable that the peak is present.

[0050] The immobilized complex catalyst of Aspect 11 is the same as that of Aspect 10, but preferably contains, by mass %, more than 0% to 5% of at least one metal element selected from the group consisting of iridium, rhodium, ruthenium, cobalt, osmium, nickel, iron, palladium, platinum, and gold.

[0051] The immobilized complex catalyst of Aspect 12, in Aspect 10 or Aspect 11, preferably contains, in mass %, from 0 to 5% Ir, from 0 to 10% C, and from 0 to 5% N.

[0052] The immobilized complex catalyst of Aspect 13 is any one of Aspects 10 to 12, wherein the support has a crystalline and / or glass composition of SiO ２ It is preferred that the compound contains:

[0053] The immobilized complex catalyst of Aspect 14 is any one of Aspects 10 to 13, wherein the support has an average pore diameter of 1 nm to 1000 nm and a specific surface area of ​​1 m ２ / g~1500m ２ / g.

[0054] The immobilized complex catalyst of Aspect 15 is preferably any one of Aspects 10 to 14, wherein the five-membered ring ligand is a pentamethylcyclopentadienyl anion and / or a pentamethylcyclopentadienyl derivative.

[0055] The immobilized complex catalyst of Aspect 16 is preferably used in any one of Aspects 1 to 15 for producing hydrogen and / or carbon dioxide from formic acid.

[0056] A method for producing an immobilized complex catalyst according to Aspect 17 of the present invention is a method for producing an immobilized complex catalyst, characterized by comprising: a surface modification step of introducing a linker moiety capable of forming an amine bond with a ligand onto the surface of a carrier using a silane coupling agent; an amine bonding step of bonding the linker moiety and the ligand via an amine bond; and a catalyst synthesis step of coordinately bonding the ligand bonded to the linker moiety via the amine bond to a metal atom of a complex catalyst precursor, thereby synthesizing a complex catalyst.

[0057] A method for producing an immobilized complex catalyst according to Aspect 18 of the present invention is a method for producing an immobilized complex catalyst, characterized by comprising: a surface modification step of introducing a linker moiety capable of forming an amine bond with the complex catalyst onto the surface of a carrier using a silane coupling agent; and a catalyst immobilization step of bonding the linker moiety and the complex catalyst via an amine bond.

[0058] In the method for producing an immobilized complex catalyst of Aspect 19, in Aspect 17 or Aspect 18, it is preferable that the silane coupling agent is represented by the following formula (40):

[0059]

[0060] [In the formula (40), R ４９ represents a halogeno group or an alkoxy group, and R ５０ and R ４８ each independently represents a halogeno group, an alkoxy group, an alkyl group, an alkenyl group, or an alkynyl group; Z ４ represents a substituted aliphatic group, an unsubstituted aliphatic group, a substituted aromatic group, or an unsubstituted aromatic group; X ２９ represents a halogeno group.

[0061] The method for producing an immobilized complex catalyst of Aspect 20 is preferably any one of Aspects 17 to 19, wherein the ligand or the ligand of the complex catalyst is represented by the following formula (41) to formula (44), and the amino group and / or the five-membered ring amine structure of the ligand or the ligand of the complex catalyst is bonded to the linker moiety via an amine bond:

[0062]

[0063]

[0064]

[0065]

[0066] [In the formulas (41) to (44), the bond order between the elements forming the ligand is a single bond or a double bond, the heterocycle forming the ligand is an aromatic ring or a non-aromatic ring, and X ３０ ~X ５７ are each independently a carbon atom, a nitrogen atom, an oxygen atom, or a sulfur atom, and R in the formula (41) ５１ ~R ５８ , R in the formula (42) ５９ ~R ６５ , R in the formula (43) ６６ ~R ７１ and R in the formula (44) ７２ ~R ７５In each formula, at least one is an amino group (provided that in each of the formulas (42) and (43), X ｉ (i is any one of 43 to 48 and 51 to 53) is a nitrogen atom, and when there is at least one amine structure in which a hydrogen atom is bonded to the nitrogen atom, R ５９ ~R ６５ and R in the formula (43) ６６ ~R ７１ may not have an amino group in each formula), R ５１ ~R ７６ Among these, those that are not amino groups are each independently a hydrogen atom, an alkyl group, a hydroxy group, an alkoxy group, a nitro group, a halogeno group, a sulfone group, a carboxylic acid group, an amino group, an alkylamino group, a phenyl group, or adjacent R ｉ (i is 51 to 75) form a ring, and Q ８ is an oxygen atom, a sulfur atom, or a selenium atom.

[0067] The method for producing an immobilized complex catalyst according to Aspect 21 is preferably any one of Aspects 17 to 20, further comprising a catalyst additional immobilization step of additionally immobilizing a complex catalyst.

[0068] According to the present invention, it is possible to devise an immobilized complex catalyst that has high catalytic activity and is capable of maintaining the catalytic activity, and a method for producing the same.

[0069] FIG. 1 is a schematic diagram showing the configuration of the continuous stirred tank reactor used in Example 6. FIG. 2 is a graph showing the measurement results of the gas production rate of a mixed gas of hydrogen and carbon dioxide generated by a formic acid dehydrogenation reaction in Experiment 1 of Example 6. FIG. 3 is a graph showing the measurement results of the cumulative gas production amount of a mixed gas of hydrogen and carbon dioxide generated by a formic acid dehydrogenation reaction in Experiment 1 of Example 6. FIG. 4 is a graph showing the result of temperature-programmed oxidation measurement for the immobilized complex catalyst D-1 of Example 6. FIG. 5 is a graph showing the result of temperature-programmed oxidation measurement for the immobilized complex catalyst D-1-R20 of Example 6. FIG. 6 is a graph showing the result of temperature-programmed oxidation measurement for the immobilized complex catalyst D-1-R100 of Example 6.

[0070] Preferred embodiments will be described below, but the following embodiments are merely examples and the present invention is not limited to the following embodiments.

[0071] [Immobilized Complex Catalyst] The immobilized complex catalyst of the present invention is an immobilized complex catalyst in which a support and a complex catalyst are bonded via a linker moiety. In the present invention, the support and the complex catalyst are bonded via the linker moiety as shown in the following formula (1) and / or the following formula (2), and the complex catalyst and the linker moiety are bonded via an amine bond.

[0072]

[0073]

[0074] In formula (1) and formula (2), L ｐ M ｋ represents a complex catalyst bonded to a linker moiety, and L ｐ M ｋ The remaining portion represents a complex formed by binding the linker portion to the carrier.

[0075] In the complex catalyst, L ｐ represents p ligands, which may be the same or different. At least one of the ligands preferably has at least one amino group as a functional group. The other ligands preferably have at least one functional group selected from, for example, a hydroxyl group, an amino group, a dimethylamino group, a diethylamino group, a pyrrolidine group, an imino group, an amide group, a carboxyl group, and a mercapto group. Examples of the ligand L include nitrogen ligands such as pyridine, bipyridine, pyrimidine, bipyrimidine, imidazole, imidazoline, and amide; π ligands such as cyclopentadienyl, pentamethylpentadienyl, benzene, and hexamethylbenzene; and halide ions (Cl － ,Br － ), water, alkoxy, hydride, acetonitrile, etc., where p is an integer of 1 to 4.

[0076] M ｋrepresents k metal atoms, which may be the same or different. M corresponds to the central metal of the complex catalyst. M is preferably iridium, rhodium, ruthenium, cobalt, nickel, iron, palladium, or platinum. Note that k is an integer of 1 to 4.

[0077] In the complex, R １ ~R ６ each independently represents a halogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, a hydroxy group, -O-*, or -O-. In this specification, the "*" in "-O-*" represents a carrier. The "." in "-O-." represents another Si atom in the linker part of the same immobilized complex catalyst, or a Si atom in the linker part of another immobilized complex catalyst. In addition, in "-O-*" and "-O-.", - represents a bond, and O represents an oxygen atom. In addition, in R of formula (1), １ ~R ３ and R in formula (2) １ ~R ６ In each of the formulae, at least one is —O—*, which bonds the linker portion to the carrier.

[0078] Z １ and Z ２ each independently represents a substituted aliphatic group, an unsubstituted aliphatic group, a substituted aromatic group, or an unsubstituted aromatic group.

[0079] Q １ and Q ２ are each independently a hydrogen atom, an alkyl group, or a linker moiety represented by the following formula (3) or the above-mentioned complex.

[0080]

[0081] In formula (3), R ７ ~R ９ each independently represents a halogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, a hydroxy group, -O-*, or -O-. ３represents a substituted aliphatic group, an unsubstituted aliphatic group, a substituted aromatic group, or an unsubstituted aromatic group. The rightmost bond in formula (3) is bonded to the nitrogen atom in formula (1) or (2).

[0082] In the immobilized complex catalyst of the present invention, the support and the complex catalyst are bonded via at least one amine bond, as shown in formulas (1) and (2). This makes it possible to create an immobilized complex catalyst that has high catalytic activity and can maintain its catalytic activity.

[0083] Specifically, in the immobilized complex catalyst of the present invention, the amine bond allows the complex catalyst to be more strongly bound to the support than when the complex catalyst is physically adsorbed to the support. Furthermore, the complex catalyst is more strongly bound to the support than when the support and the complex catalyst are bound via an ionic bond. Furthermore, the complex catalyst can be stably immobilized to the support regardless of the charge state around the immobilized complex catalyst (e.g., the liquid phase when the immobilized complex catalyst is used in a liquid phase). Therefore, the immobilized complex catalyst of the present invention can easily maintain its catalytic activity and stably exhibit the excellent activity and selectivity of the complex catalyst before immobilization for a long period of time. The immobilized complex catalyst of the present invention can be used, for example, as an immobilized complex catalyst in which a dehydrogenation catalyst capable of stably converting a hydrogen carrier such as formic acid to hydrogen and carbon dioxide is immobilized on a support, even under high-pressure conditions.

[0084] In the present invention, the complex catalyst preferably contains, as an active ingredient, a complex catalyst represented by any one of the following formulas (4) to (7) or a salt of the complex catalyst, or an isomer of the complex catalyst represented by any one of the following formulas (4) to (7) or a salt of the isomer:

[0085]

[0086]

[0087]

[0088]

[0089] In formulas (4) to (7), the metal atom of M is iridium, rhodium, ruthenium, cobalt, osmium, nickel, iron, palladium, platinum, or gold. Among the ligands, L is an aromatic anion ligand or an aromatic ligand. When L has a substituent, the number of the substituents is one or more, and an indenyl ligand, a pentamethylcyclopentadienyl ligand, a hexamethylbenzene ligand, or the like can be used. As the aromatic anion ligand, a cyclopentadienyl ligand, an indenyl ligand, a pentamethylcyclopentadienyl ligand, or the like can be used. As the aromatic ligand, a cyclobutadiene ligand, a benzene ligand, a hexamethylbenzene ligand, a cyclooctatetraene ligand, or the like can be used. Among the other ligands, A １ Is, H ２ O, hydride (hydrogen, H － ), formate ion (HCO ２ － ), hydroxide ions (OH － ), or alkoxide ions (RO － ) is shown. － ) and alkoxy groups, R is a substituted aliphatic group, an unsubstituted aliphatic group, a substituted aromatic group, or an unsubstituted aromatic group.

[0090] L and A １ In the ligands other than those shown in the above, the bond order between the elements forming the ligand is a single bond or a double bond, and the heterocycle forming the ligand is an aromatic ring or a non-aromatic ring. １ ~X ２８ are each independently a carbon atom, a nitrogen atom, an oxygen atom, or a sulfur atom. １０ ~R １７ , R in formula (5) １８ ~R ２４ , R in formula (6) ２５ ~R ３０ , and R in formula (7) ３１ ~R ３４ In each formula, at least one of X is bonded to the linker portion via an amine bond. ｉWhen R (i is any of 14 to 19 and 22 to 24) is a nitrogen atom, the nitrogen atom may form an amine bond with the linker moiety. １０ ~R ３５ Among these, those that are not bonded to the linker portion by an amine bond are each independently a hydrogen atom, an alkyl group, a hydroxy group (—OH), an alkoxy group (—OR), a nitro group, a halogeno group, a sulfone group, a carboxylic acid group, an amino group, an alkylamino group, a phenyl group, or an adjacent R ｉ (i is 10 to 34) form a ring. ３ is an oxygen atom, a sulfur atom, or a selenium atom. m and n are each a positive integer or 0 and indicate an ionic valence. [c] ｎ－ is a hydroxide ion (OH － ), sulfate ions (SO ４ ２－ ), chloride ions (Cl － ), bromine ion (Br － ), nitrate ions (NO ３ － ), and hexafluorophosphate ion (PF ６ － ) is one of the ions.

[0091] In the present invention, the complex catalyst may contain, as an active ingredient, a complex catalyst represented by any one of the following formulas (8) to (11) or a salt of the complex catalyst, or an isomer of the complex catalyst represented by any one of the following formulas (8) to (11) or a salt of the isomer:

[0092]

[0093]

[0094]

[0095]

[0096] In formulas (8) to (11), one of the ligands is a pentamethylcyclopentadienyl ligand. １ Is, H ２ O, hydride (hydrogen, H － ), formate ion (HCO ２－ ), hydroxide ions (OH － ), or alkoxide ions (RO － ) represents the pentamethylcyclopentadienyl ligand and A １ In the ligands other than those shown in the above, the bond order between the elements forming the ligand is a single bond or a double bond, and the heterocycle forming the ligand is an aromatic ring or a non-aromatic ring. １ ~X ２８ are each independently a carbon atom, a nitrogen atom, an oxygen atom, or a sulfur atom. １０ ~R １７ , R in formula (9) １８ ~R ２４ , R in formula (10) ２５ ~R ３０ , and R in formula (11) ３１ ~R ３４ In each formula, at least one of X is bonded to the linker portion via an amine bond. ｉ When R (i is any of 14 to 16, 17 to 19, and 22 to 24) is a nitrogen atom, the nitrogen atom may form an amine bond with the linker moiety. １０ ~R ３５ Among these, those that are not bonded to the linker portion by an amine bond are each independently a hydrogen atom, an alkyl group, a hydroxy group (—OH), an alkoxy group (—OR), a nitro group, a halogeno group, a sulfone group, a carboxylic acid group, an amino group, an alkylamino group, a phenyl group, or an adjacent R ｉ (i is 10 to 34) form a ring. ３ is an oxygen atom, a sulfur atom, or a selenium atom. m and n are each a positive integer or 0 and indicate an ionic valence. [c] ｎ－ is a hydroxide ion (OH － ), sulfate ions (SO ４ ２－ ), chloride ions (Cl － ), bromine ion (Br － ), nitrate ions (NO ３ － ), and hexafluorophosphate ion (PF ６ － ) is one of the ions.

[0097] In the present invention, the complex catalyst may contain, as an active ingredient, a complex catalyst represented by any one of the following formulas (12) to (18) or a salt of the complex catalyst, or an isomer of the complex catalyst represented by any one of the following formulas (12) to (18) or a salt of the isomer of the complex catalyst:

[0098]

[0099]

[0100]

[0101]

[0102]

[0103]

[0104]

[0105] In formulas (12) to (18), one of the ligands is a pentamethylcyclopentadienyl ligand. １ Is, H ２ O, hydride (hydrogen, H － ), formate ion (HCO ２ － ), hydroxide ions (OH － ), or alkoxide ions (RO － ) represents the pentamethylcyclopentadienyl ligand and A １ In the ligand other than １０ ~R １７ , R in formula (13) １８ ~R ２４ , R in formula (14) １８ and R ２０ ~R ２４ , R in formula (15) １８ ~R ２４ , R in formula (16) １８ ~R ２４ , R in formula (17) ２５ ~R ３０ , and R in formula (18) ２５ ~R ３０In each of the formulas, at least one is bonded to the linker portion via an amine bond. ２２ , and R in (17) and (18) ２７ and R ２８ is bonded to the linker portion via an amine bond, R ｉ (i is 22, 27, or 28) may be bonded to a nitrogen atom of the five-membered aromatic heterocyclic ring, which may form an amine bond with the linker moiety. １０ ~R ３０ Among these, those that are not bonded to the linker portion by an amine bond are each independently a hydrogen atom, an alkyl group, a hydroxy group (—OH), an alkoxy group (—OR), a nitro group, a halogeno group, a sulfone group, a carboxylic acid group, an amino group, an alkylamino group, a phenyl group, or an adjacent R ｉ (i is 10 to 30) form a ring together. m and n are each a positive integer or 0 and indicate an ionic valence. [c] ｎ－ is a hydroxide ion (OH － ), sulfate ions (SO ４ ２－ ), chloride ions (Cl － ), bromine ion (Br － ), nitrate ions (NO ３ － ), and hexafluorophosphate ion (PF ６ － ) is one of the ions.

[0106] In the present invention, the complex catalyst may contain, as an active ingredient, a complex catalyst represented by any one of the following formulas (19) to (22) or a salt of the complex catalyst, or an isomer of the complex catalyst represented by any one of the following formulas (19) to (22) or a salt of the isomer of the complex catalyst:

[0107]

[0108]

[0109]

[0110]

[0111] In formulas (19) to (22), one of the ligands is a pentamethylcyclopentadienyl ligand. １ Is, H ２ O, hydride (hydrogen, H － ), formate ion (HCO ２ － ), hydroxide ions (OH － ), or alkoxide ions (RO － ) represents the pentamethylcyclopentadienyl ligand and A １ In the ligand other than １２ and R １５ , R in formula (20) １２ and R １５ , R in formula (21) １８ , R ２０ , and R ２２ , and R in formula (22) ２７ and R ２８ In each formula, at least one of the R ２２ , and R in formula (22) ２７ and R ２８ is bonded to the linker portion via an amine bond, R ｉ (i is 22, 27, or 28) may be bonded to the linker moiety via an amine bond at the nitrogen atom of the five-membered aromatic heterocyclic ring. １２ , R １５ , R １８ , R ２０ , R ２２ , R ２７ , and R ２８ [c], those that are not bonded to the linker moiety via an amine bond are each independently a hydrogen atom, an alkyl group, a hydroxy group (—OH), an alkoxy group (—OR), a nitro group, a halogeno group, a sulfone group, a carboxylic acid group, an amino group, an alkylamino group, or a phenyl group. m and n are each a positive integer or 0 and indicate an ionic valence. ｎ－ is a hydroxide ion (OH － ), sulfate ions (SO ４ ２－ ), chloride ions (Cl － ), bromine ion (Br －), nitrate ions (NO ３ － ), and hexafluorophosphate ion (PF ６ － ) is one of the ions.

[0112] Examples of the immobilized complex catalyst of the present invention using such a complex catalyst include immobilized complex catalysts containing at least one structure represented by the following formulas (23) to (39).

[0113]

[0114]

[0115]

[0116]

[0117]

[0118]

[0119]

[0120]

[0121]

[0122]

[0123]

[0124]

[0125]

[0126]

[0127]

[0128]

[0129]

[0130] In the formulas (23) to (39), one of the ligands is a pentamethylcyclopentadienyl ligand. ２ Is, H ２O, hydride (hydrogen, H － ), formate ion (HCO ２ － ), hydroxide ions (OH － ), or alkoxide ions (RO － ) represents the pentamethylcyclopentadienyl ligand and A ２ In the ligand other than ３６ ~R ４７ each independently represents a halogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, a hydroxy group, -O-*, or -O-. ３６ ~R ３８ , R in formula (24) ３６ ~R ４１ , R in formula (25) ３６ ~R ４１ , R in formula (26) ３６ ~R ４４ , R in formula (27) ３６ ~R ４７ , R in formula (28) ３６ ~R ３８ , R in formula (29) ３６ ~R ４１ , R in formula (30) ３６ ~R ４１ , R in formula (31) ３６ ~R ４４ , R in formula (32) ３６ ~R ４７ , R in formula (33) ３６ ~R ３８ , R in formula (34) ３６ ~R ４１ , R in formula (35) ３６ ~R ４４ , R in formula (36) ３６ ~R ３８ , R in formula (37) ３６ ~R ４１ , R in formula (38) ３６ ~R ３８ , R in formula (39) ３６ ~R ４１ In each formula, at least one is -O-*, and the linker portion is bonded to the carrier. ７７is a hydrogen atom, an alkyl group, a hydroxy group (—OH), an alkoxy group (—OR), a nitro group, a halogeno group, a sulfone group, a carboxylic acid group, an amino group, an alkylamino group, or a phenyl group. ４ ~Q ７ are each independently a hydrogen atom or an alkyl group. t is a positive integer or 0 and represents the length of the aliphatic group having no substituent. m and n are positive integers and / or 0 and represent ionic valences. [c] ｎ－ is a hydroxide ion (OH － ), sulfate ions (SO ４ ２－ ), chloride ions (Cl － ), bromine ion (Br － ), nitrate ions (NO ３ － ), and hexafluorophosphate ion (PF ６ － ) is one of the ions.

[0131] In the immobilized complex catalyst of the present invention, the amount of the complex catalyst supported is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and even more preferably 1.0% by mass or more, and is preferably 90% by mass or less, based on 100% by mass of the immobilized complex catalyst. When the amount of the complex catalyst supported is within the above range, the catalytic activity per unit volume can be further increased.

[0132] The immobilized complex catalyst of the present invention is an immobilized complex catalyst in which a complex catalyst is supported on a carrier, and the complex catalyst contains at least one metal element selected from the group consisting of iridium, rhodium, ruthenium, cobalt, osmium, nickel, iron, palladium, platinum, and gold, and a ligand containing a five-membered ring ligand and / or an amine, and the immobilized complex catalyst has a specific surface area obtained by solid-state NMR measurement. ２９ In the Si-NMR spectrum, T ３ It may have a peak.

[0133] Even when the immobilized complex catalyst of the present invention has such a structure, it is possible to create an immobilized complex catalyst that has high catalytic activity and is capable of maintaining the catalytic activity.

[0134] The immobilized complex catalyst of the present invention preferably contains at least one metal element selected from the group consisting of iridium, rhodium, ruthenium, cobalt, osmium, nickel, iron, palladium, platinum, and gold. The concentration of the metal element is preferably greater than 0% by mass and up to 5% by mass, more preferably 0.01% by mass to 5% by mass, even more preferably 0.02% by mass to 4% by mass, and particularly preferably 0.03% by mass to 2% by mass. If the concentration of the metal element is too low, the catalytic performance of the immobilized complex catalyst may not be obtained. On the other hand, if the concentration of the metal element is too high, the metal element may be easily detached from the immobilized complex catalyst, potentially reducing the performance retention rate of the catalyst. Here, the concentration of the metal element (metal element concentration) is a value measured using inductively coupled plasma atomic emission spectroscopy (ICP-AES). For example, the metal element concentration can be measured using an ICP-AES device. As an ICP-AES device, for example, an Agilent 5110 model manufactured by Agilent Technologies can be used. More specifically, the dried immobilized complex catalyst is first fractionated and weighed, the sample is fused with an alkali, and then dissolved in an acid, followed by adding ultrapure water to a constant volume to obtain a test solution, which is then quantitatively analyzed using an ICP-AES device, thereby measuring the metal element concentration. The metal element concentration is preferably measured using the immobilized complex catalyst before and after immersion in a formic acid aqueous solution. After the immersion in formic acid, the immobilized complex catalyst is preferably washed with water to remove adsorbed substances such as formic acid.

[0135] The immobilized complex catalyst of the present invention preferably has a carbon content of more than 0% by mass to 10% by mass, more preferably 0.01% by mass to 10% by mass, even more preferably 0.02% by mass to 5% by mass, and particularly preferably 0.03% by mass to 3% by mass. The immobilized complex catalyst of the present invention also preferably has a nitrogen content of more than 0% by mass to 5% by mass, more preferably 0.001% by mass to 5% by mass, even more preferably 0.002% by mass to 1% by mass, and particularly preferably 0.003% by mass to 0.8% by mass. If the carbon and nitrogen contents of the immobilized complex catalyst are too low, the catalytic performance of the immobilized complex catalyst may not be achieved. If the carbon and nitrogen contents of the immobilized complex catalyst are too high, organic components may be easily desorbed from the immobilized complex catalyst, potentially resulting in a low catalyst performance retention rate. The carbon and nitrogen contents of the immobilized complex catalyst are values ​​measured by a combustion method or a temperature-programmed oxidation method. For example, the carbon content and nitrogen content of the immobilized complex catalyst can be measured by a combustion method using an elemental analyzer. An example of an elemental analyzer that can be used is the "NC-22F" manufactured by Sumika Chemical Analysis Center. More specifically, the immobilized complex catalyst is first pretreated by drying at 80°C to 140°C for 0.5 to 5 hours, and 1 mg to 500 mg of sample is then taken and weighed. Next, the immobilized complex catalyst is subjected to combustion oxidation, and the generated gas is introduced into a thermal conductivity detector. Total carbon is determined from the amount of carbon determined from carbon dioxide in the gas, and total nitrogen is determined from the amount of nitrogen obtained by reducing nitrogen oxides. The temperature during combustion oxidation is preferably 800°C to 1000°C, the reduction temperature is preferably 500°C to 700°C, and oxygen is preferably used as the feed gas. The carbon content of the immobilized complex catalyst can also be measured using temperature-programmed oxidation (TPO). More specifically, 0.01 g to 1.0 g of the immobilized complex catalyst is first packed into a quartz tube, which is then inserted into an electric heating furnace. While circulating air gas (nitrogen:oxygen = 80:20) through the quartz tube at 100 mL / min, the temperature of the electric heating furnace is increased from room temperature to 800°C to 1000°C at 10°C / min.The gas generated by the temperature-raised oxidation was passed through a Pt catalytic reactor heated to 350°C and completely converted into carbon dioxide, after which it was analyzed by a mass flow meter and ND-IR. ２ The gas flow rate and carbon dioxide concentration were measured using a sensor (GMP252, manufactured by Vaisala). ２ The temperature profile of the production rate and the carbon content can be measured. ２ For example, a sensor such as "GMP252" manufactured by Vaisala can be used. ２ It is preferable to calibrate the sensitivity of the sensor. ２ The sensitivity of the sensor can be calibrated by passing a carbon dioxide standard gas of known concentration (1000 ppm nitrogen balance). For analyzing the carbon and nitrogen contents of the immobilized complex catalyst, it is preferable to use the immobilized complex catalyst before and after immersion in an aqueous formic acid solution. Furthermore, it is preferable to wash the immobilized complex catalyst after immersion in formic acid with water before analysis to remove adsorbed substances such as formic acid.

[0136] Taking these into consideration, the immobilized complex catalyst of the present invention may contain, for example, in mass %, Ir from 0% to 5%, C from 0% to 10%, and N from 0% to 5%.

[0137] The immobilized complex catalyst of the present invention has a low CO ２ The temperature profile of the production rate preferably has at least one peak in the temperature range of 300°C to 400°C. In particular, the peak in the temperature range of 300°C to 400°C preferably shifts to a higher temperature within the range of 300°C to 400°C as the immobilized complex catalyst is immersed in an aqueous formic acid solution. In addition, the immobilized complex catalyst of the present invention has a high CO2 content measured by a temperature-programmed oxidation method. ２ The temperature profile of the production rate may have at least one peak in the temperature range of 400°C to 600°C.

[0138] The ligand of the immobilized complex catalyst of the present invention preferably includes a five-membered ring anionic ligand and an amine-containing ligand. The five-membered ring anionic ligand is preferably a pentamethylcyclopentadienyl ligand and / or a cyclopentadienyl ligand. The amine-containing ligand is preferably a ligand represented by formulas (41) to (55) described below. In pyrolysis gas chromatography-mass spectrometry, the immobilized complex catalyst having the above-mentioned ligands can be subjected to detection of, for example, five-membered ring fragments and amine-containing fragments. Examples of five-membered ring fragments that can be detected include 1,2,3,4,5-pentamethylcyclopentadiene, cyclopentadiene, and 1,2,3,4-tetramethyl-5-methylene-1,3-cyclopentadiene. Furthermore, examples of amine-containing fragments that can be detected include (2S)-2-amino-N-ethylpropanamide, 1-methoxy-2-propanamine, L-alanine, DL-α-alanine, ethyl 2-aminopropionate, 1-(2-aminoethyl)aziridine, N-methyl-1-octanamine, 1,2-propanediamine, D-cycloserine, [(aminocarbonyl)amino]oxoacetic acid, 5-amino-6-nitroso-pyrimidine-2,4(1H,3H)-dione, 2-amino-1-propanol, 1-methylbutylamine, 1-cyclohexylethanamine, 6-methyl-2-heptanamine, 3-oxo-butanenitrile, 1-methyldodecylamine, 5-methyl-2-heptanamine, 1-methylhexylamine, and undecane-2-amine. In addition to the five-membered ring fragments and amine-containing fragments, examples of suitable amine fragments include carbon dioxide, pentane, 2-methyl-1-propanol, 2,2-dimethyl-1,3-dioxane-4,6-dione, 2-oxopropanoic acid, 2,3-dimethyloxirane, 2-methyl-1-pentene, methylcyclopentane, methoxyethane, methoxyacetic acid, dimethyl sulfide, 2,2,3-trimethylbutane, hexane, cyclohexane, tetrahydrofuran, 2,4-dimethylfuran, 2,5-dimethylfuran, 4-ethyl-1,3-dioxolane, 2-methoxy-1-propene, benzene, butadienylacetylene, 2,4-hexadiyne, 1,2-dimethyl-1-pentylcyclopropane, 2-cyclopropylpentane, 2,6-dimethyl-3-heptene, (Z)-2,3-dimethyl-3-heptene, 1,2,4,4-tetramethylcyclopentene, 6,6-dimethylhepta-2,4-diene, 2,3-dimethyl-1,3-heptadiene, 2,6-dimethyl-2,4-heptadiene, 2,6-dimethyl-3-octene, 2-cyclopropyl-pentane, 2,6-dimethyl-2-octene, 1,2-dimethyl-3-pentylcyclopropane, 2,4-dimethyl-1-heptene, 3,7-dimethyl 1-octene, 4-methyl-1-heptene, 5-methyl-1-heptene, 2-ethyl-1-pentanol, cyclopropyl methyl ketone, 1,5,5,6-tetramethyl-1,3-cyclohexadiene, 1,2,6,6-tetramethyl-1,3-cyclohexadiene, (E,Z)-2,6-dimethyl-2,4,6-octatriene, 1,6-dimethylhepta-1,3,5-triene, 1,2,5,5-tetramethyl-1,3-cyclopentadiene, 5-(1,1-dimethylethyl)-1,3-cyclopentadiene, 2,6-dimethylhepta-3, 5-dien-2-ol, (E,Z)-2,6-dimethyl-2,4,6-octatriene, 3,4-dimethyl-2,4,6-octatriene, methyl-benzene, 1,2,4-trimethyl-benzene, 1-ethyl-3-methyl-benzene, 1-ethyl-2-methyl-benzene, 1-ethyl-3-methyl-benzene, 1-ethyl-4-methyl-benzene, 4-ethyl-1,2-dimethyl-benzene, 1-methyl-2-(1-methylethyl)-benzene, 1-methyl-3-(1-methylethyl)-benzene, 2-ethyl-1,4-dimethyl-benzene, 3 , 7-dimethyl-1-octanol, (Z)-3-tetradecene, 6-methyl-1-heptanol, 1,2,4,5-tetramethyl-benzene, 1,2,3,5-tetramethyl-benzene, 1-methyl-4-(1-methylethenyl)-benzene, 1-methyl-2-isopropenylbenzene, (2-methyl-1-propenyl)-benzene, 1-ethenyl-2,4-dimethyl-benzene, 1,2,3,4-tetramethyl-benzene, 7-methyl-1-undecene, 1-ethyl-naphthalene, 2-ethyl-naphthalene, 1,3-dimethyl-naphthalene, 1,2-dimethyl-naphthalene, 2,3-dimethyl-naphthalene, diethyl phthalate, dodecane, 2,6,11-trimethyl-dodecane, 2,3,5,8-tetramethyl-decane, 2,6,10-trimethyl-tetradecane, 2,3,3-trimethyl-octane, 3,4,5,6-tetramethyl-octane, 2-methyl-4-heptanone, tridecane, 3-(2-methylpropyl)-cyclohexene, 1-butyl-cyclohexene, 3-butyl-cyclohexene, 4-butyl-cyclohexene, 3-octyl-cyclohexene, 2,6,10,15-tetramethyl-octane, Fragments such as methyl heptadecane, nonadecane, 3,8-dimethyl undecane, 2,6,10,14-tetramethyl hexadecane, 3-methyl-5-propyl nonane, docosane, octacosane, tetracosane, eicosane, octadecane, heneicosane, tetratetracontane, hexatriacontane, hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, tetradecamethylcyclotetradecaneheptasiloxane, etc. may also be detected.

[0139] Pyrolysis gas chromatography mass spectrometry can be performed, for example, using a gas chromatograph mass spectrometer with a pyrolyzer connected to the sample introduction section. Examples of pyrolyzers that can be used include the "EGA / PY-3030D" manufactured by Frontier Labs. Examples of gas chromatograph mass spectrometers that can be used include the "GCMS QP-2010Ultra" manufactured by Shimadzu Corporation. In pyrolysis gas chromatograph mass spectrometers, examples of separation columns that can be used include the "Ultra ALLOY UA5 (MS / HT)-30M-0.25F" manufactured by Frontier Labs. Pyrolysis gas chromatograph mass spectrometry can be performed using the following measurement procedures and conditions. First, the immobilized complex catalyst is inserted into the pyrolyzer and heated from room temperature to approximately 600°C. The gas generated by pyrolysis is then injected into the gas chromatograph mass spectrometer for analysis. The measurement data is analyzed using software attached to the gas chromatograph mass spectrometer, and the compounds of the peaks in the pyrogram are identified by a similarity search using a library from the mass spectrum of the peaks. The NIST mass spectral library (NIST08, NIST08s) is preferably used as the library.

[0140] The immobilized complex catalyst is ２９ Measured by Si solid state NMR ２９ In the Si-NMR spectrum, T ３ It is preferable that the immobilized complex catalyst has a peak. An immobilized complex catalyst having such a peak means that there is a Si atom having three covalent bonds selected from Si—O—· and / or Si—O—* and one Si—C covalent bond (- indicates a bond, * indicates a support, and • indicates another Si atom in the linker part of the same immobilized complex catalyst, or a Si atom in the linker part of another immobilized complex catalyst). In other words, since the linker part of the immobilized complex catalyst is trifunctionally bonded by a siloxane bond, the complex catalyst is stably immobilized on the support, and catalytic activity can be maintained. Furthermore, the immobilized complex catalyst has a T at a chemical shift value of −40 ppm to −60 ppm. １Peak, T at chemical shift values ​​of -45 ppm to -65 ppm ２ It may have a peak. １ The peak indicates that a Si atom having one covalent bond selected from Si—O— or Si—O—*, one Si—C covalent bond, and two hydroxy groups is present in the immobilized complex catalyst. ２ The peak indicates the presence of a Si atom having two covalent bonds selected from Si—O— and / or Si—O—*, one Si—C covalent bond, and one hydroxyl group. The immobilized complex catalyst has SiO as a crystal and / or glass composition on the support. ２ When the compound contains Q, the chemical shift value is −85 ppm to −120 ppm. ２ Peak and / or Q ３ Peak and / or Q ４ It may have a peak. ２ The peaks correspond to Si atoms with two siloxane bonds and two silanol groups, Q ３ The peaks correspond to Si atoms with three siloxane bonds and one silanol group, Q ４ The peak indicates the presence of a Si atom having four siloxane bonds. ２９ Si solid-state NMR can be measured using, for example, a digital NMR device. An example of a digital NMR device that can be used is the AVANCEIII HD 400 model manufactured by Bruker Japan. Measurement techniques include cross polarization magic angle spinning (CPMAS) and dipolar decoupling magic angle spinning (DDMAS). It is preferable to use an immobilized complex catalyst before and / or after immersion in a formic acid aqueous solution as the measurement sample. In particular, it is preferable to use an immobilized complex catalyst that has been immersed in a formic acid aqueous solution for 100 hours as the measurement sample.

[0141] The carrier used in the present invention preferably has a surface capable of forming an amine bond. For example, the carrier preferably has a hydrophilic group (e.g., an OH group) on its surface. The hydrophilic group may be a silanol group. In this case, by subjecting the carrier to a silane coupling treatment in the manufacturing process described below, the amine bond between the complex catalyst and the carrier can be more effectively promoted. However, the carrier does not necessarily need to be surface-treated in the manufacturing process described below, and the carrier itself may have a surface capable of forming an amine bond.

[0142] The carrier can be selected depending on the target catalytic reaction and the conditions of use. Examples of carriers that can be used include porous materials, metal oxides, porous metal oxides, silica gel, zeolites, mesoporous silicates, porous glass, clay, porous metal oxides (MOFs), porous polymer beads, porous carbons such as carbon nanotubes and activated carbon, ceramic honeycombs, metal honeycombs, porous polymers, silica particles, and polymer particles. Among these, the carrier preferably contains any of porous glass, silica gel, and mesoporous silica, from the viewpoints of thermal and mechanical stability, and the presence of hydroxyl groups on the surface, which makes surface treatment easier. Furthermore, from the viewpoints of easier molding processability and surface treatment, it is preferable to use a porous glass carrier. Porous glass carriers can be produced, for example, by eluting one phase of spinodally phase-separated glass with an acid and / or alkali. Furthermore, from the viewpoints of ease of surface treatment and further improvement in durability to formic acid and abrasion resistance, it is preferable to use silica gel as the carrier. Furthermore, from the viewpoint of increasing the amount of immobilized complex catalyst, it is preferable to use mesoporous silica having a large specific surface area as the carrier.

[0143] The support is preferably made of an oxide containing a metal element such as silicon, boron, sodium, aluminum, calcium, magnesium, potassium, titanium, phosphorus, beryllium, scandium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, gallium, germanium, strontium, yttrium, cadmium, indium, tin, barium, or a lanthanoid element. Furthermore, the support is preferably a porous oxide containing such a metal oxide. The metal oxide may be a single metal oxide containing only one of the above metal elements, or a composite metal oxide containing two or more of the above metal elements. In particular, the support is preferably made of a metal oxide containing one or more of the above metal elements, such as silicon, zirconium, boron, sodium, aluminum, calcium, magnesium, potassium, titanium, or phosphorus.

[0144] The average pore diameter of the support is preferably 1000 nm or less. More specifically, from the viewpoint of suitable use as a heterogeneous catalyst in a liquid phase, the average pore diameter of the support is preferably 6 nm to 100 nm, and more preferably 20 nm to 80 nm. Furthermore, from the viewpoint of suitable use as a heterogeneous catalyst in a gas phase, the average pore diameter of the support is preferably 1 nm to 100 nm, and more preferably 1 nm to 80 nm. If the average pore diameter of the support is too large, the specific surface area tends to be too small. If the average pore diameter of the support is too small, it becomes difficult for the complex catalyst to be supported in the pores. Note that the average pore diameter of the support before amine-bonding the complex catalyst substantially corresponds to the average pore diameter of the immobilized complex catalyst after amine-bonding the complex catalyst. In the present invention, the average pore diameter of the support is a value calculated by analyzing a desorption isotherm obtained by a nitrogen gas adsorption method using a specific surface area / pore size distribution measuring device by the Barrett-Joyner-Halenda (BJH) method. As the specific surface area / pore size distribution measuring device, for example, an Anton Paar model (product number: QUADRASORB SI) can be used. In the examples described below, the average pore diameter of the support was measured using this specific surface area / pore size distribution measuring device.

[0145] The specific surface area of ​​the carrier is not particularly limited, but from the viewpoint of suitable use as a liquid phase heterogeneous catalyst, it is preferably 1 m ２ / g~1500m ２ / g, and 20m ２ / g~800m ２ / g, more preferably 50m ２ / g~500m ２ / g is even more preferable. If the specific surface area of ​​the carrier is too large, the average pore diameter of the carrier tends to be too small. The specific surface area of ​​the carrier is a value calculated by analyzing an adsorption isotherm obtained by a nitrogen gas adsorption method using a specific surface area / pore distribution measuring device, using the Brunauer-Emmett-Teller (BET) method. As the specific surface area / pore distribution measuring device, for example, an Anton Paar model (product number "QUADRASORB SI") can be used. In the examples described later, the specific surface area of ​​the carrier was measured using this specific surface area / pore distribution measuring device.

[0146] The shape of the carrier is not particularly limited, and it can be in the form of powder, granules, pellets, plates, tubes, cylinders, spheres, discs, or the like.

[0147] The immobilized complex catalyst of the present invention may further include a support. More specifically, the immobilized complex catalyst may be used in a state where it is supported on a support. The shape of the support is not particularly limited as long as it is a shape that can support the immobilized complex catalyst on its surface. Examples of the shape of the support include a flat plate, a block, a fiber, a net, a bead, and a honeycomb. Alternatively, an immobilized complex catalyst prepared in powder form can be attached to the surface of a honeycomb support. Alternatively, a carrier (e.g., porous glass) can be supported on the surface of the honeycomb support, and the complex catalyst can be bound to this carrier (e.g., porous glass).

[0148] The material of the support is not particularly limited as long as it is stable under the loading and reaction conditions. For example, various ceramics and metal honeycomb can be used as the support.

[0149] The immobilized complex catalyst of the present invention is preferably used as a heterogeneous catalyst in a liquid phase or a gas phase. The immobilized complex catalyst of the present invention is preferably used, for example, for the decomposition of formic acid and the production of hydrogen and / or carbon dioxide. More specifically, the immobilized complex catalyst is more preferably used for the production of hydrogen by the decomposition of formic acid.

[0150] For example, in the presence of the immobilized complex catalyst of the present invention, formic acid can be decomposed in a liquid phase (water) to suitably produce hydrogen and / or carbon dioxide. The temperature during decomposition is preferably about 0°C to 150°C. The concentration of the formic acid aqueous solution is preferably 0.1% by mass to 99.99% by mass, more preferably 5% by mass to 50% by mass. The amount of the immobilized complex catalyst used is preferably equal to or less than the weight of the formic acid aqueous solution, more preferably equal to or less than one-tenth the weight of the formic acid aqueous solution. If the amount of the immobilized complex catalyst used is too large, the amount of the immobilized complex catalyst used increases without contributing to improvement of the reaction efficiency, which may result in a lack of economic rationality.

[0151] The immobilized complex catalyst can be used in a reactor. The type of reactor in which the immobilized complex catalyst is used is not particularly limited, and examples thereof include a fixed-bed flow reactor, a packed-bed flow reactor, a multi-tubular fixed-bed reactor, a multi-stage fixed-bed reactor, a countercurrent fixed-bed reactor, a parallel-flow fixed-bed reactor, a radial fixed-bed reactor, a honeycomb catalytic reactor, a monolith catalytic reactor, a slurry reactor, a membrane separation reactor, a microreactor, a plug flow reactor (PFR), a fixed-bed batch reactor, a fluidized-bed batch reactor, a moving-bed batch reactor, a packed-bed batch reactor, a fluidized-bed flow reactor, a moving-bed flow reactor, an autoclave reactor, a semi-batch reactor, a loop reactor, a rotating disk reactor, a rotating basket reactor, a continuous stirred tank reactor (CSTR), a pulse reactor, and a cross-flow reactor.

[0152] For example, when a formic acid decomposition reaction is carried out using a continuous stirred tank reactor, the following procedure is followed: The reaction solution (formic acid aqueous solution) and the immobilized complex catalyst are placed in a reactor tank. The space above the liquid surface at the top of the reactor is purged with an inert gas before the reaction begins, and a collection port is provided to capture the gas generated by the reaction. A pump is used to pump the formic acid aqueous solution from the raw material tank into the reactor tank at a constant flow rate, and the reaction solution is continuously discharged from the reactor to maintain a constant liquid volume. The reaction solution may be unstirred, with the immobilized complex catalyst sinking to the bottom, or it may be stirred using a stirring blade or other means to move the immobilized complex catalyst. By heating the reaction solution to a constant temperature, formic acid is decomposed into hydrogen and carbon dioxide on the surface of the immobilized complex catalyst, generating bubbles that move to the liquid surface. The decomposition gases that accumulate in the space above the liquid surface are collected through a collection port.

[0153] The size of the reactor is not particularly limited. As long as the residence time τ, which will be described below, is kept constant, the same reaction rate can be obtained regardless of the size of the reactor. The residence time τ (h) is calculated by dividing the volume of reaction liquid (L) in the reactor by the feed pump flow rate (L / h). While the value is not particularly limited, it is preferably 0.01 h to 100 h, more preferably 1 h to 100 h. If the residence time τ is too short, the aqueous formic acid solution may be discharged from the reactor without being able to sufficiently react with the immobilized complex catalyst, resulting in a decrease in the reaction rate. Furthermore, if the residence time τ is too long, the concentration of the aqueous formic acid solution in the reactor may decrease, resulting in a decrease in the catalytic activity of the immobilized complex catalyst.

[0154] The weight (amount used) of the immobilized complex catalyst used is preferably equal to or less than the weight of the reaction solution, and more preferably equal to or less than one-tenth of the weight of the reaction solution. If the amount of immobilized complex catalyst used is too large, the amount of immobilized complex catalyst used increases without contributing to improving the reaction efficiency, which may result in a lack of economic rationality. The stirring speed is not particularly limited, but is preferably 100 rpm or less from the viewpoint of avoiding damage to the immobilized complex catalyst due to stirring. If the stirring speed is too high, the immobilized complex catalyst may be severely damaged by wear, resulting in deterioration of the immobilized complex catalyst. Furthermore, if the reaction solution is kept uniform by foaming during the reaction, convection due to heating, or the like, mechanical stirring is not necessary.

[0155] The liquid temperature during decomposition may be any temperature between 0°C and 100°C, and is preferably between 10°C and 90°C. If the liquid temperature is too low, the catalytic activity of the immobilized complex catalyst may decrease. On the other hand, if the liquid temperature is too high, the immobilized complex catalyst may be prone to deterioration. The concentration of the aqueous formic acid solution is preferably between 0.1% by mass and 99.99% by mass, and more preferably between 5% by mass and 50% by mass. If the concentration of the aqueous formic acid solution is too low or too high, the catalytic activity of the immobilized complex catalyst may decrease.

[0156] The produced mixed gas of hydrogen and carbon dioxide can be extracted at normal pressure, or it can be extracted as a high-pressure gas by installing a back pressure valve at the outlet. Furthermore, by installing a hydrogen / carbon dioxide separator at the tip of the outlet, it is possible to generate or produce hydrogen gas and / or carbon dioxide gas.

[0157] [Method for producing immobilized complex catalyst] The immobilized complex catalyst of the present invention can be produced, for example, by the following first method or second method. Hereinafter, the first method and the second method may be collectively referred to as the method for producing the immobilized complex catalyst of the present invention.

[0158] The first method is a method for producing an immobilized complex catalyst, and includes a surface modification step of using a silane coupling agent to introduce a linker moiety capable of forming an amine bond with a ligand onto the surface of a support; an amine bonding step of bonding the linker moiety and the ligand via an amine bond; and a catalyst synthesis step of coordinating the ligand bonded to the linker moiety via the amine bond to a metal atom of a complex catalyst precursor, thereby synthesizing a complex catalyst.

[0159] The second method is a method for producing an immobilized complex catalyst, and includes a surface modification step in which a linker moiety capable of forming an amine bond with the complex catalyst is introduced onto the surface of the support using a silane coupling agent, and a catalyst immobilization step in which the linker moiety and the complex catalyst are bonded via an amine bond.

[0160] The method for producing an immobilized complex catalyst of the present invention includes a surface modification step in which a support is surface-treated with a silane coupling agent and a linker moiety capable of forming an amine bond with a ligand or a ligand of the complex catalyst is introduced onto the surface of the support. By including this surface modification step, it is possible to introduce onto the surface of the support a linker moiety capable of forming an amine bond with the ligand, thereby effectively forming an amine bond between the support and the complex catalyst.

[0161] The functional group to be introduced onto the surface of the support is preferably, for example, a halogenated alkyl group. More specifically, the functional group to be introduced onto the surface of the support is preferably at least one selected from the group consisting of an alkyl fluoride, an alkyl chloride, an alkyl bromide, and an alkyl iodide.

[0162] In the surface modification step, the support is surface-treated using a silane coupling agent, and a linker moiety capable of forming an amine bond with a ligand or a ligand of a complex catalyst is introduced onto the surface of the support. The support before the surface treatment preferably has a hydrophilic group (e.g., an OH group) on its surface. The hydrophilic group may be a silanol group. Furthermore, the silane coupling agent preferably has a structure represented by the following formula (40):

[0163]

[0164] In formula (40), R ４９ is, for example, a group that can be substituted with a hydrophilic group on the surface of the carrier, and represents a halogeno group or an alkoxy group. ５０ and R ４８ each independently represents a halogeno group, an alkoxy group, an alkyl group, an alkenyl group, or an alkynyl group. ４ represents an aliphatic group having a substituent, an aliphatic group having no substituent, an aromatic group having a substituent, or an aromatic group having no substituent. ２９ represents a halogeno group.

[0165] Examples of such silane coupling agents include 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 3-chloropropyltrichlorosilane, 3-chloropropyldimethylchlorosilane, 3-chloropropyldichloromethylsilane, chloromethyldimethylchlorosilane, 3-chloropropyldimethoxymethylsilane, 3-chloropropyldiethoxymethylsilane, 4-chlorophenyltrimethoxysilane, 4-chlorophenyltrimethoxysilane, chloromethyldimethylethoxysilane, chloromethyltrimethoxysilane, chloromethylmethoxydimethylsilane, chloromethylmethyldichlorosilane, 1-chloroethyltrichlorosilane, chloromethyltrichlorosilane, 3-bromopropyltrimethoxysilane, 3-bromopropyltriethoxysilane, 3-bromopropyltrichlorosilane, 3-bromopropyldimethylchlorosilane, bromomethyldimethylchlorosilane, 1,2-dibromoethyltrichlorosilane, 3-iodopropyltrimethoxysilane, or 3-iodopropyltriethoxysilane.

[0166] In the surface modification step, the carrier can be surface-treated by, for example, immersing the carrier in a solution containing a silane coupling agent. Examples of the solvent used include toluene, hexane, tetrahydrofuran (THF), and isopropanol. One solvent may be used alone, or two or more solvents may be used in combination. After the surface treatment, the carrier may be washed with an organic solvent or the like and then dried.

[0167] The temperature during the surface treatment may be set appropriately taking into consideration the boiling point of the solvent used, etc., but is preferably, for example, 5°C to 100°C. The surface treatment time is not particularly limited, but is preferably, for example, 0.1 hours to 500 hours. The concentration of the silane coupling agent in the solution is preferably 1 mmol / L to 1000 mmol / L. The amount of silane coupling agent used is preferably 0.01 g to 5 g per 1 g of carrier (glass, etc.).

[0168] By carrying out the surface modification step, for example, R of the silane coupling agent represented by formula (40)４８ , R ４９ , or R ５０ However, this reacts with the hydrophilic group on the surface of the carrier, and a carrier having a linker portion capable of forming an amine bond with the ligand or the ligand of the complex catalyst can be obtained.

[0169] (First Method) In the first method, for example, the linker portion introduced onto the support surface is bonded to the ligand of the complex catalyst only via an amine bond, and then the central metal of the complex catalyst is introduced. Specifically, first, the support with the linker portion introduced onto its surface is immersed in a solution containing the ligand (ligand solution), and the ligand is immobilized on the support. For example, when the ligand has an amino group, the linker portion introduced onto the support surface is reacted with the amino group of the ligand to form an amine bond, thereby immobilizing the ligand on the support. Note that the ligand may have a five-membered ring amine structure instead of an amino group, and the five-membered ring amine structure may be reacted with the linker portion. Next, the support with the immobilized ligand is immersed in a complex catalyst precursor solution containing the central metal (complex catalyst precursor solution), thereby obtaining an immobilized complex catalyst.

[0170] As the ligand, for example, ligands represented by the following formulas (41) to (44) can be used.

[0171]

[0172]

[0173]

[0174]

[0175] In formulas (41) to (44), the bond order between the elements forming the ligand is a single bond or a double bond, and the heterocycle forming the ligand is an aromatic ring or a non-aromatic ring. ３０ ~X ５７ are each independently a carbon atom, a nitrogen atom, an oxygen atom, or a sulfur atom. ５１ ~R ５８ , R in formula (42) ５９ ~R ６５ , R in formula (43) ６６ ~R ７１ , and R in formula (44)７２ ~R ７５ In each of the formulas (42) and (43), at least one of X is an amino group. ｉ (i is any one of 43 to 48 and 51 to 53) is a nitrogen atom, and at least one amine structure (H-N=) formed by bonding a hydrogen atom to the nitrogen atom is present, R ５９ ~R ６５ and R in formula (43) ６６ ~R ７１ may not have an amino group in each formula. ５１ ~R ７６ Among these, those that are not amino groups are each independently a hydrogen atom, an alkyl group, a hydroxy group, an alkoxy group, a nitro group, a halogeno group, a sulfone group, a carboxylic acid group, an amino group, an alkylamino group, a phenyl group, or adjacent R ｉ (i is 51 to 75) form a ring. ８ is an oxygen atom, a sulfur atom, or a selenium atom.

[0176] As the ligand, ligands represented by the following formulae (45) to (51) may be used.

[0177]

[0178]

[0179]

[0180]

[0181]

[0182]

[0183]

[0184] In formulas (45) to (51), R in formula (45) ５１ ~R ５８ , R in formula (46) ５９ ~R ６５ , R in formula (47) ５９ and R ６１ ~R ６５ , R in formula (48)５９ ~R ６５ , R in formula (49) ５９ ~R ６５ , R in formula (50) ６６ ~R ７１ , and R in formula (51) ６６ ~R ７１ In each formula, at least one is an amino group. ６３ , R in formula (47) ６３ , R in formula (48) ６３ , R in formula (50) ６８ and R ６９ , and R in formula (51) ６８ and R ６９ In the formulas, at least one is a hydrogen atom, and when there is at least one amine structure in which a hydrogen atom is bonded to a nitrogen atom, R in formula (46) ５９ ~R ６５ , R in formula (47) ５９ and R ６１ ~R ６５ , R in formula (48) ５９ ~R ６５ , R in formula (50) ６６ ~R ７１ , and R in formula (51) ６６ ~R ７１ may not have an amino group in each formula. ５１ ~R ７１ are not amino groups, each independently represents a hydrogen atom, an alkyl group, a hydroxy group (—OH), an alkoxy group (—OR), a nitro group, a halogeno group, a sulfone group, a carboxylic acid group, an amino group, an alkylamino group, or a phenyl group, or adjacent R ｉ (i is 51 to 71) form a ring.

[0185] As the ligand, ligands represented by the following formulae (52) to (55) may be used.

[0186]

[0187]

[0188]

[0189]

[0190] In formulas (52) to (55), R in formula (52) ５３ and R ５６ , R in formula (53) ５３ and R ５６ , R in formula (54) ５９ , R ６１ , and R ６３ , R in formula (55) ６８ and R ６９ In each formula, at least one is an amino group. ６３ , and R in formula (55) ６８ and R ６９ In the formulas, at least one is a hydrogen atom, and when there is at least one amine structure in which a hydrogen atom is bonded to a nitrogen atom, R in formula (54) ５９ , R ６１ , and R ６３ , and R in formula (55) ６８ and R ６９ may not have an amino group in each formula. ５３ , R ５６ , R ５９ , R ６１ , R ６３ , R ６８ , and R ６９ Among these, those that are not amino groups are the same or different and are a hydrogen atom, an alkyl group, a hydroxy group (—OH), an alkoxy group (—OR), a nitro group, a halogeno group, a sulfone group, a carboxylic acid group, an amino group, an alkylamino group, or a phenyl group.

[0191] When immobilizing a ligand on a support, it is preferable to adjust the pH of the solution to basic so that amine bonds can be easily formed between the support having a linker moiety introduced on its surface and the ligand. The pH of the solution is preferably 7 to 14, more preferably 7.2 to 12, even more preferably 7.5 to 10, and particularly preferably 7.8 to 9.5. The solvent is not particularly limited, but examples include water, dimethyl sulfoxide, acetone, methanol, and ethanol. One solvent may be used alone, or two or more solvents may be used in combination. To adjust the pH, sodium carbonate, sodium bicarbonate, sodium hydroxide, a buffer solution, or the like may be dissolved in the solvent.

[0192] The temperature of the ligand solution may be set appropriately taking into consideration the boiling point of the solvent used, and is preferably, for example, 5°C to 100°C. The immersion time of the support is preferably, for example, 0.1 hours to 500 hours. The concentration of the ligand in the solution is preferably 0.1 mmol / L to 1000 mmol / L. In this case, the amount of the ligand used is preferably 0.005 g to 0.5 g per 1 g of support.

[0193] After mixing, it is preferable to include a step of washing the carrier after immersion to remove excess salts.

[0194] Next, the central metal is introduced and bonded to the ligand. Specifically, the support on which the ligand is immobilized is immersed in a complex catalyst precursor solution containing the central metal, thereby bonding the central metal to the ligand immobilized on the support, thereby obtaining an immobilized complex catalyst.

[0195] In the present invention, the complex catalyst precursor may contain, as an active ingredient, a complex catalyst precursor represented by any one of the following formulas (56) to (58) or a salt of the complex catalyst precursor, or an isomer of the complex catalyst precursor represented by any one of the following formulas (56) to (58) or a salt of the isomer of the complex catalyst precursor:

[0196]

[0197]

[0198]

[0199] In the formulas (56) to (58), the metal atom of M is iridium, rhodium, ruthenium, cobalt, osmium, nickel, iron, palladium, platinum, or gold. ２ ~L ６ are each independently an aromatic anion ligand or an aromatic ligand. Examples of aromatic anion ligands that can be used include cyclopentadienyl ligands, indenyl ligands, and pentamethylcyclopentadienyl ligands. Examples of aromatic ligands that can be used include cyclobutadiene ligands, benzene ligands, hexamethylbenzene ligands, and cyclooctatetraene ligands. ２ ~L ６ When J has a substituent, the number of the substituents is 1 or 2 or more, and an indenyl ligand, a pentamethylcyclopentadienyl ligand, a hexamethylbenzene ligand, etc. can be used. １ ~J １０ are each independently H ２ O, hydride (hydrogen, H － ), formate ion (HCO ２ － ), hydroxide ions (OH － ), chloride ions (Cl － ), bromine ion (Br － ), iodine ion (I － ), or alkoxide ions (RO － m and / or n are positive integers or 0 and represent ionic valence. [c] ｎ－ is a hydroxide ion (OH － ), sulfate ions (SO ４ ２－ ), chloride ions (Cl － ), bromine ion (Br － ), nitrate ions (NO ３ － ), and hexafluorophosphate ion (PF ６ － ) is one of the ions.

[0200] In the present invention, the complex catalyst precursor may contain, as an active ingredient, a complex catalyst precursor represented by any one of the following formulas (59) to (61) or a salt of the complex catalyst precursor, or an isomer of the complex catalyst precursor represented by any one of the following formulas (59) to (61) or a salt of the isomer of the complex catalyst precursor:

[0201]

[0202]

[0203]

[0204] In formulas (59) to (61), J １ ~J １０ are each independently H ２ O, hydride (hydrogen, H － ), formate ion (HCO ２ － ), hydroxide ions (OH － ), chloride ions (Cl － ), bromine ion (Br － ), iodine ion (I － ), or alkoxide ions (RO － m and n are positive integers or 0 and represent ionic valences. [c] ｎ－ is a hydroxide ion (OH － ), sulfate ions (SO ４ ２－ ), chloride ions (Cl － ), bromine ion (Br － ), nitrate ions (NO ３ － ), and hexafluorophosphate ion (PF ６ － ) is one of the ions.

[0205] In the present invention, the complex catalyst precursor may contain, as an active ingredient, a complex catalyst precursor represented by any one of the following formulas (62) to (64) or a salt of the complex catalyst precursor, or an isomer of the complex catalyst precursor represented by any one of the following formulas (62) to (64) or a salt of the isomer of the complex catalyst precursor:

[0206]

[0207]

[0208]

[0209] In formulas (62) to (64), m and n are positive integers or 0 and indicate ionic valence. [c] ｎ－ is a hydroxide ion (OH － ), sulfate ions (SO ４ ２－ ), chloride ions (Cl － ), bromine ion (Br － ), nitrate ions (NO ３ － ), hexafluorophosphate ion (PF ６ － ) is one of the ions.

[0210] The solvent used for the complex catalyst precursor solution is not particularly limited, but examples thereof include water, methanol, ethanol, etc. The solvent may be used alone or in combination of two or more.

[0211] The temperature of the complex catalyst precursor solution may be appropriately set taking into consideration the boiling point of the solvent used, and may be, for example, 5°C to 100°C. The time for immersing the support having the immobilized ligand in the complex catalyst precursor solution may be, for example, 0.1 to 500 hours. The concentration of the complex catalyst precursor in the complex catalyst precursor solution is preferably 0.1 mmol / L to 1000 mmol / L. The amount of the complex catalyst precursor used is preferably 0.001 g to 0.5 g per gram of the support having the immobilized ligand. The pH of the complex catalyst precursor solution may be adjusted to a basic value, and sodium carbonate, sodium bicarbonate, sodium hydroxide, a buffer solution, or the like may be dissolved in the solvent to adjust the pH.

[0212] The first method preferably includes a step of washing the carrier after immersion to remove excess salts. The carrier after washing is then dried to obtain the immobilized complex catalyst of the present invention.

[0213] (Second Method) In the second method, for example, a linker moiety introduced onto the surface of a carrier is directly bonded to a complex catalyst via an amine bond. Specifically, a carrier having a linker moiety introduced onto its surface is immersed in a solution containing a complex catalyst, and the linker moiety introduced onto the carrier surface reacts with an amino group on the complex catalyst to form an amine bond, thereby immobilizing the complex catalyst on the carrier. This allows the immobilized complex catalyst of the present invention to be obtained.

[0214] The complex catalyst preferably contains, as an active ingredient, a complex catalyst represented by any one of the above formulas (4) to (7), a salt of the complex catalyst, or an isomer or a salt of the isomer of the complex catalyst represented by any one of the above formulas (4) to (7). The complex catalyst may also contain, as an active ingredient, a complex catalyst represented by any one of the above formulas (8) to (11), any one of the formulas (12) to (18), or any one of the formulas (19) to (22), or a salt of the complex catalyst, or an isomer or a salt of the isomer of the complex catalyst represented by any one of the above formulas (8) to (11), any one of the formulas (12) to (18), or any one of the formulas (19) to (22).

[0215] When immobilizing a complex catalyst on a support, it is preferable to adjust the pH of a solution containing the complex catalyst to a basic value so that amine bonding between the support having a linker moiety introduced onto its surface and the complex catalyst (ligand of the complex catalyst) is facilitated. The pH of the solution is preferably 7 to 14, more preferably 7.2 to 12, even more preferably 7.5 to 10, and particularly preferably 7.8 to 9.5. The solvent is not particularly limited, but examples include water, methanol, ethanol, dimethyl sulfoxide, and acetone. One solvent may be used alone, or two or more solvents may be used in combination. Furthermore, to adjust the pH, sodium carbonate, sodium bicarbonate, sodium hydroxide, a buffer solution, or the like may be dissolved in the solvent.

[0216] The temperature of the solution containing the complex catalyst may be appropriately set taking into consideration the boiling point of the solvent used, etc., but is preferably, for example, 5°C to 100°C. The immersion time of the support is preferably, for example, 0.1 hours to 500 hours. The concentration of the complex catalyst in the solution containing the complex catalyst is preferably 0.1 mmol / L to 1000 mmol / L. In this case, the amount of the complex catalyst used is preferably 0.001 g to 0.5 g per 1 g of the support.

[0217] In the second method, it is also preferable to include a step of washing the carrier after immersion to remove excess salts. The carrier after washing can be dried to obtain the immobilized complex catalyst of the present invention.

[0218] The method for producing an immobilized complex catalyst of the present invention may include a catalyst additional immobilization step of additionally immobilizing a complex catalyst. For example, the additional complex catalyst can be supported by immersing the immobilized complex catalyst in a solution containing the complex catalyst.

[0219] The additionally immobilized complex catalyst preferably contains, as an active ingredient, a complex catalyst represented by any one of the above formulas (4) to (7), or a salt of the complex catalyst, or an isomer or a salt of the isomer of the complex catalyst represented by any one of the above formulas (4) to (7). The complex catalyst may also contain, as an active ingredient, a complex catalyst represented by any one of the above formulas (8) to (11), any one of the formulas (12) to (18), or any one of the formulas (19) to (22), or a salt of the complex catalyst, or an isomer or a salt of the isomer of the complex catalyst represented by any one of the above formulas (8) to (11), any one of the formulas (12) to (18), or any one of the formulas (19) to (22).

[0220] The solvent used for the solution containing the complex catalyst is not particularly limited, and examples thereof include water, dimethyl sulfoxide, acetone, methanol, and ethanol. One solvent may be used alone, or two or more solvents may be used in combination. The pH of the solution containing the complex catalyst may be adjusted to a basic value, and sodium carbonate, sodium bicarbonate, sodium hydroxide, a buffer solution, or the like may be dissolved in the solvent to adjust the pH.

[0221] The temperature of the solution containing the complex catalyst may be appropriately set taking into consideration the boiling point of the solvent used, etc., but is preferably, for example, 5°C to 100°C. The immersion time of the immobilized complex catalyst is preferably, for example, 0.1 hours to 500 hours. The concentration of the complex catalyst in the solution is preferably 0.01 mmol / L to 1000 mmol / L.

[0222] The catalyst additional immobilization step also preferably includes a step of washing the immobilized complex catalyst after immersion to remove excess salts. The immobilized complex catalyst of the present invention can be obtained by drying the washed immobilized complex catalyst.

[0223] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

[0224] In the examples, the average pore size and specific surface area of ​​the porous glass carrier were measured by nitrogen gas adsorption using a gas adsorption apparatus (manufactured by Anton Paar, product number "QUADRASORB SI"). The compositions of the porous glass carrier and silica gel carrier were analyzed by EDX (energy dispersive X-ray analyzer, manufactured by Horiba, Ltd., product number "EMAX Evolution EX-370 X-Max150" or product number "EMAX Evolution X-Max20") or XRF (scanning X-ray fluorescence analyzer, manufactured by Rigaku Corporation, product number "ZSX Primus4").

[0225] [Example 1] (Porous glass carrier I) Glass composition: 62.5SiO ２ ・28.3B ２ O ３ 9.2Na ２A tubular glass plate (glass tube) having an outer diameter of 4 mm to 9 mm and a wall thickness of 0.8 mm to 1.3 mm was prepared using a fluorine-containing glass substrate (fluorine-containing glass substrate) manufactured by fluorine-containing glass chemistry. The glass tube was then placed in alumina powder and heated in an electric furnace at 600°C for 72 hours in air, thereby causing phase separation into a silica-rich phase and a boron oxide-rich phase, thereby obtaining a phase-separated glass tube. The phase-separated glass tube was placed in 0.5 mol / L sulfuric acid and maintained at 99°C for 96 hours, thereby removing the boron oxide-rich phase, thereby obtaining a porous glass carrier I. The porous glass carrier I had an average pore size (diameter) of 46 nm and a specific surface area of ​​59 m. ２ The composition of the porous glass carrier I was analyzed to find that it was 96.7SiO ２ ・3.0B ２ O ３ ・0.3Na ２ It was O.

[0226] (Porous Glass Carrier II) A porous glass carrier having a glass composition of 83.0SiO was prepared in the same manner as in the porous glass carrier I. ２ 11.0 ZrO ２ ・3.0Al ２ O ３ ・2.0P ２ O ５ ・1.0TiO ２ The porous glass carrier II had an average pore size (diameter) of 40 nm and a specific surface area of ​​80 m. ２ / g.

[0227] (Surface Treatment of Porous Glass Carrier) The obtained porous glass carriers I and II (hereinafter also simply referred to as porous glass carriers) were vacuum-dried at 140°C for 3 hours and then surface-treated. The surface treatment conditions for the porous glass carriers are shown in Table 1. Specifically, first, 3-bromopropyltriethoxysilane was added to 25 mL of toluene in an amount equivalent to 0.3 g per 1 g of porous glass carrier, and the porous glass carrier was immersed in the resulting solution and maintained at room temperature for 24 hours, followed by maintaining at 90°C for 24 hours. Note that the porous glass carrier I used in the immobilized complex catalyst I-1 described below was only subjected to a treatment of maintaining at 90°C for 24 hours. Furthermore, the porous glass carrier II used in the immobilized complex catalysts II-1 and II-2 described below was only subjected to a treatment of maintaining at room temperature for 24 hours. Next, the porous glass carrier after the surface treatment was immersed in toluene and maintained at 90°C for 3 to 24 hours to wash. The porous glass carriers I and II used in the immobilized complex catalysts I-1 and II-1 described below were washed with toluene and ethanol at room temperature without being washed at 90° C. After washing, the porous glass carrier was air-dried.

[0228]

[0229] (Immobilized Complex Catalysts I-1 and II-1) Immobilized complex catalysts I-1 and II-1 were prepared by immersing a surface-treated porous glass carrier in an iridium complex catalyst solution. The immersion conditions are shown in Table 2. The production method is described in more detail below.

[0230]

[0231] (Immobilized Complex Catalyst I-1) A pentamethylcyclopentadiene (pentamethylcyclopentadienyl ligand, Cp ＊ ), 4,4'-diamino-2,2'-bipyridine (4,4'-diamino-2,2'-bipyridine, 4,4'-(NH ２ ) ２ -bpy) and water molecules (aqua, H ２ O) coordinated iridium complex catalyst ([(Cp ＊ Ir(4,4'-(NH ２ ) ２ -bpy) (H２ O) ]SO ４ , A in equation (19) １ H ２ O, R １２ , R １５ Both are NH ２ , [c] ｎ－ is sulfate ion (SO ４ ２－ )) was dissolved in a weakly alkaline (pH 8.5) aqueous sodium bicarbonate solution to obtain an iridium complex catalyst solution with a concentration of 0.05% by mass (0.5 mg / mL). The air-dried and surface-treated porous glass carrier I described above was immersed in the iridium complex catalyst solution and maintained at 90°C for 48 hours. Thereafter, it was washed with distilled water and air-dried to obtain an immobilized complex catalyst. More specifically, an immobilized complex catalyst I-1 was obtained in which the iridium complex catalyst was supported on the porous glass carrier I.

[0232] (Immobilized Complex Catalyst II-1) Iridium Complex Catalyst ([(Cp ＊ Ir(4,4'-(NH ２ ) ２ -bpy) (H ２ O) ]SO ４ , A in equation (19) １ H ２ O, R １２ , R １５ Both are NH ２ , [c] ｎ－ is sulfate ion (SO ４ ２－ )) was dissolved in water to obtain an iridium complex catalyst solution with a concentration of 0.025% by mass (0.25 mg / mL). The porous glass carrier II that had been air-dried and surface-treated as described above was immersed in the iridium complex catalyst solution and maintained at 80°C for 24 hours. Thereafter, it was washed with distilled water and air-dried to obtain an immobilized complex catalyst. More specifically, an immobilized complex catalyst II-1 in which the iridium complex catalyst was supported on the porous glass carrier II was obtained.

[0233] Immediately after immersion of porous glass carrier I or II in the iridium complex catalyst solution, the porous glass carrier was colorless, but over time it assumed the same ochre color as the iridium complex and then changed to brownish-red. The resulting immobilized complex catalysts I-1 and II-1 were brownish-red, and neither was discolored when washed with water. Furthermore, even when these immobilized complex catalysts were immersed in 0.01 mol / L sulfuric acid at 60°C for 1 hour or more, no detachment of the iridium complex catalyst was observed. Furthermore, even when these immobilized complex catalysts were immersed in 1 mol / L aqueous sodium bicarbonate solution at 60°C for 1 hour or more, no detachment of the iridium complex catalyst was observed. From these results, it is believed that the iridium complex catalyst is firmly bound to the porous glass carrier in the prepared immobilized complex catalysts.

[0234] (Immobilized Complex Catalysts I-2 and II-2) Immobilized complex catalysts I-2 and II-2 were prepared by the following procedure. First, 4,4'-diamino-2,2'-bipyridine (4,4'-(NH ２ ) ２ -bpy, R in equation (52) ５３ , R ５６ Both are NH ２ The surface-treated porous glass carrier was immersed in a solution in which 4,4'-(NH ２ ) ２ A porous glass carrier on which 4,4'-(NH ２ ) ２ The porous glass support on which -bpy was immobilized was immersed in an iridium precursor solution to prepare immobilized complex catalysts I-2 and II-2. The immersion conditions are shown in Tables 3 and 4. The production methods are described in more detail below.

[0235]

[0236]

[0237] (Immobilized Complex Catalyst I-2) First, 4,4'-diamino-2,2'-bipyridine (4,4'-(NH ２) ２ -bpy, R in equation (52) ５３ , R ５６ Both are NH ２ ) was dissolved in a weakly alkaline (pH 8.5) aqueous sodium bicarbonate solution to give a concentration of 0.6 mg / ml of 4,4'-(NH ２ ) ２ A 4,4'-(NH ２ ) ２ The surface-treated porous glass carrier I after air drying was immersed in the 4,4'-(NH-bpy) solution and kept at 90°C for 48 hours, and then immersed in distilled water and kept at 90°C for 24 hours, followed by washing with water. ２ ) ２ Porous glass I on which -bpy was immobilized was obtained.

[0238] Next, an iridium precursor ([Cp ＊ Ir(H ２ O) ３ ]SO ４ ) was dissolved in water to obtain an iridium precursor solution with a concentration of 0.05 mass % (0.5 mg / mL). ２ ) ２ The iridium complex-immobilized porous glass carrier I was immersed in the catalyst and allowed to stand at room temperature for 48 hours. The catalyst was then washed with distilled water at room temperature and air-dried to obtain an immobilized complex catalyst I-2 in which an iridium complex was immobilized.

[0239] (Immobilized Complex Catalyst II-2) First, 4,4'-diamino-2,2'-bipyridine (4,4'-(NH ２ ) ２ -bpy) was dissolved in a weakly alkaline (pH 8.5) aqueous sodium bicarbonate solution to give a concentration of 0.8 mg / ml of 4,4'-(NH ２ ) ２ A 4,4'-(NH ２ ) ２ The surface-treated porous glass carrier II after air drying was immersed in the 4,4'-(NH-bpy) solution and kept at 90°C for 24 hours, and then immersed in distilled water and kept at 90°C for 24 hours, followed by washing with water. ２ )２ Porous glass II on which -bpy was immobilized was obtained.

[0240] Next, an iridium precursor ([Cp ＊ Ir(H ２ O) ３ ]SO ４ , [c] in equation (62) ｎ－ is sulfate ion (SO ４ ２－ )) was dissolved in water to obtain an iridium precursor solution with a concentration of 0.05% by mass (0.5 mg / mL). ２ ) ２ The iridium complex-immobilized porous glass carrier II was immersed in the catalyst and allowed to stand at room temperature for 24 hours. The catalyst was then washed with distilled water at room temperature and air-dried to obtain an immobilized complex catalyst II-2 in which an iridium complex was immobilized.

[0241] (Immobilized Complex Catalysts I-3 and II-3) Immobilized complex catalysts prepared in the same manner as immobilized complex catalysts I-2 and II-2 (details of the surface treatment conditions are shown in Table 1, and details of the immersion conditions in the organic ligand and iridium precursor solution are shown in Tables 3 and 4) were further treated with an iridium complex catalyst ([(Cp ＊ Ir(4,4'-(NH ２ ) ２ -bpy) (H ２ O) ]SO ４ The conditions for the additional loading are shown in Table 2. Specifically, the immobilized complex catalyst I-2 or II-2 was immersed in a 0.05 mass % (0.5 mg / mL) iridium complex catalyst solution prepared using water as the solvent at 90°C for 24 hours to additionally load the iridium complex catalyst, and then washed with water at 90°C for 24 hours and air-dried to obtain immobilized complex catalysts I-3 and II-3.

[0242] Comparative Example (Carboxylation Surface Treatment of Porous Glass Carrier I) Porous glass carrier I was vacuum-dried at 140°C for 3 hours and then subjected to a surface treatment. Specifically, 3-cyanopropyltriethoxysilane was added to 25 mL of toluene in an amount equivalent to 0.3 g per 1 g of porous glass carrier I, and the porous glass carrier I was immersed in the resulting solution and maintained at 90°C for 24 hours. Next, the surface-treated porous glass carrier I was immersed in toluene and maintained at 90°C for 24 hours for cleaning. After cleaning, the porous glass carrier I was air-dried. Next, the resulting surface-modified porous glass carrier I was placed in 20 mL of hydrogen peroxide solution (30% by Wako Pure Chemical Industries, Ltd.) and allowed to react at room temperature for 24 hours, converting the terminal groups of the surface-modified porous glass carrier I into carboxyl groups.

[0243] (Immobilized Complex Catalyst I-4) 60 mg of DCC (N,N'-dicyclohexylcarbodiimide) as a dehydration condensation agent was dissolved in 20 mL of distilled water, and the surface-modified porous glass carrier I with carboxyl end groups was immersed in the solution, kept at room temperature for 24 hours, and then washed with water. Next, the iridium complex catalyst ([(Cp ＊ Ir(4,4'-(NH ２ ) ２ -bpy) (H ２ O) ]SO ４ ) to NaHCO ３ The iridium complex catalyst was dissolved in water whose pH had been adjusted to 8.3 using a HCl solution containing 100% HCl and 100% HCl, to obtain an iridium complex catalyst solution with a concentration of 0.025% by mass (0.25 mg / mL). Next, the surface-modified porous glass carrier I, in which the terminal groups after the DCC treatment had been converted to carboxyl groups, was immersed in the iridium complex catalyst solution and maintained at room temperature for 48 hours. Subsequently, the carrier was heated at 60°C for 24 hours while still sealed, washed with distilled water, and then air-dried to obtain an amide bond-immobilized complex catalyst. More specifically, an amide bond-immobilized complex catalyst I-4, in which the iridium complex catalyst was supported on the porous glass carrier I, was obtained.

[0244] (Measurement of formic acid decomposition activity I) Immobilized complex catalysts I-1, I-2, I-3, and I-4 (tube-shaped with an average pore size of 46 nm, an outer diameter of 4 mm to 9 mm, and a wall thickness of 0.8 mm to 1.3 mm, 0.02 g) were placed in test tubes containing 5 mL of a 1 mol / L aqueous formic acid solution, and the tubes were capped. When the test tubes were heated to 60°C in a water bath, gas was generated vigorously immediately after heating. Furthermore, the test tubes were maintained at 60°C for 10 minutes and then placed in ice water. The generated gas was collected with a syringe and qualitatively analyzed using a gas chromatograph (Shimadzu Corporation, product number "GC-2014") to confirm the generation of hydrogen. The immobilized complex catalysts I-1, I-2, I-3, and I-4 had hydrogen production rates of 69.4 mmol / (h g), 55.8 mmol / (h g), 65.3 mmol / (h g), and 72.4 mmol / (h g), respectively.

[0245] (Measurement I of Formic Acid Decomposition Activity Maintenance) Next, 4 mL of the formic acid aqueous solution was removed from the test tube and replaced with 4 mL of fresh formic acid aqueous solution. The temperature was again raised to 60°C in the water bath, and gas began to evolve vigorously immediately after heating. The gas generated was collected with a syringe and qualitatively analyzed using a gas chromatograph (Shimadzu Corporation, product number "GC-2014") to confirm the generation of hydrogen. This procedure was repeated five times, and the hydrogen generation rates shown in Table 5 were obtained, with hydrogen being generated vigorously up to the fifth time. In Table 5 shown below, the maintenance rate is defined by the following formula and indicates the catalytic activity maintenance rate when the reaction is repeated. In Table 5 shown below, * indicates that the reaction was performed but the reaction rate was not measured.

[0246] Maintenance rate (%) = ((hydrogen generation rate at the fifth time) / (hydrogen generation rate at the first time)) x 100

[0247]

[0248] (Measurement II of formic acid decomposition activity and maintenance of formic acid decomposition activity) For immobilized complex catalysts II-1, II-2, and II-3 (average pore size 40 nm, 10 mm × 10 mm × 0.5 t, 0.02 g), the formic acid decomposition activity and the maintenance of formic acid decomposition activity were measured under the same conditions, and hydrogen generation was confirmed. Furthermore, this operation was repeated five times, and hydrogen was generated vigorously up to the fifth time. The hydrogen generation rate is shown in Table 6.

[0249]

[0250] In the case of a homogeneous catalyst, the catalyst concentration decreases to 1 / 5 each time the solution is replaced, so the fifth reaction is diluted to the fourth power of (1 / 5) of the first reaction. Therefore, the hydrogen production rate also decreases accordingly, resulting in a maintenance rate of 0.16%.

[0251] As described above, all of the immobilized complex catalysts of the present invention exhibited high initial activity (formic acid decomposition activity) of 20 mmol / (h g) or more. Furthermore, the retention rate (formic acid decomposition activity retention rate) was also high, at 5% or more. This is a significantly higher value than the 0.16% retention rate of the homogeneous catalyst, demonstrating high catalytic activity and catalytic activity retention in the formic acid decomposition reaction. Furthermore, the amide-bond-immobilized complex catalyst I-4 of the comparative example exhibited high initial activity, but its retention rate was 2.5%, less than half that of the amine-bond-immobilized complex catalyst of the example.

[0252] [Example 2] Immobilized complex catalysts A-1, B-1, C-1, and D-1 were prepared using four types of silica gel carriers, and their catalytic performance was evaluated. The method for producing the immobilized complex catalysts is described below.

[0253] (Silica Gel Carrier) Four types of silica gel carriers with different pore characteristics were prepared. The evaluation results of the pore characteristics of the silica gel carriers are shown in Table 7. In addition, composition analysis of the silica gel carriers revealed that SiO ２ The main component was silica gel, and its content was 99% or more by mass. The silica gel was approximately spherical, with a particle size of 1 mm to 3 mm. In the table, the pore size indicates the average pore size.

[0254]

[0255] (Surface treatment of silica gel carrier) The silica gel carrier and 3-bromopropyltrimethoxysilane in an amount of 0.3 g per 1 g of silica gel carrier were added to 25 mL of toluene, and the mixture was kept at room temperature for 24 hours. After the surface treatment, the silica gel carrier was washed with toluene at room temperature and air-dried.

[0256] (Immobilization treatment of complex catalyst) Iridium complex catalyst ([(Cp ＊ Ir(4,4'-(NH ２ ) ２ -bpy) (H ２ O) ]SO ４ , A in equation (19) １ H ２ O, R １２ , R １５ Both are NH ２ , [c] ｎ－ is sulfate ion (SO ４ ２－ )) was dissolved in a weakly alkaline (pH 8.3) aqueous sodium bicarbonate solution to obtain an iridium complex catalyst solution with a concentration of 0.8 mg / mL. Subsequently, a surface-treated silica gel carrier that had been air-dried was immersed in the iridium complex catalyst solution and maintained at 90°C for 24 hours, thereby immobilizing the iridium complex catalyst on the silica gel carrier. Thereafter, the silica gel carrier after the catalyst immobilization treatment was immersed in ion-exchanged water, maintained at 90°C for 24 hours to wash, and then air-dried to obtain immobilized complex catalysts A-1 (using silica gel carrier A), B-1 (using silica gel carrier B), C-1 (using silica gel carrier C), and D-1 (using silica gel carrier D).

[0257] The pore diameters (average pore diameters) and specific surface areas of the prepared immobilized complex catalysts are shown in Table 8. A decrease in the specific surface area of ​​immobilized complex catalyst A-1 was confirmed compared with silica gel carrier A, but it is believed that there was no significant change in the pore characteristics of the other samples, and the pore characteristics of the immobilized complex catalysts are equivalent to those of the silica gel carrier used.

[0258]

[0259] (Measurement of formic acid dehydrogenation activity and maintenance of formic acid dehydrogenation activity III) The immobilized complex catalysts A-1, B-1, C-1, and D-1 were each placed in a test tube containing 5 mL of a 4 mol / L formic acid aqueous solution, and the tube was capped with a butyl rubber cap. The amount of immobilized complex catalyst added was 30 mg to 50 mg. Next, a gas tube and a gas vent tube were inserted into the test tube cap, nitrogen gas was introduced into the test tube through the gas tube, and nitrogen bubbling was performed in the formic acid aqueous solution for 5 minutes. Subsequently, the gas tube and gas vent tube were removed from the test tube, and the test tube was placed in a water bath and maintained at 60°C for 10 minutes, and then placed in ice water. The generated gas was collected with a gas-tight syringe and analyzed using a gas chromatograph (Shimadzu Corporation, product number "GC-2014") to calculate the hydrogen production rate (mmol / (h g)) per mass of the immobilized complex catalyst. The measurement result was taken as the hydrogen production rate of the immobilized complex catalyst at the start of the reaction (0 hours after the start of the reaction). Next, a gas vent tube was inserted into the lid of the test tube, and the tube was placed in a hot dry bath and maintained at 60°C for 50 minutes. Thereafter, the gas vent tube and lid were removed, and the formic acid solution was removed with a Pasteur pipette while the immobilized complex catalyst was left in the test tube. The immobilized complex catalyst was washed three times with 10 mL of ion-exchanged water, and the wash water was removed from the test tube.

[0260] 5 mL of a 4 mol / L formic acid solution was placed in a test tube, which was then capped. After bubbling with nitrogen gas for 5 minutes in the same manner as in the experimental procedure described above, the test tube was placed in a water bath at 60°C for 10 minutes and then placed in ice water. The generated gas was collected with a gas-tight syringe and analyzed by gas chromatography to calculate the hydrogen production rate. The measurement result was used as the hydrogen production rate of the immobilized complex catalyst 1 hour after the start of the reaction.

[0261] Next, a degassing tube was inserted into the lid of the test tube, and the tube was placed in a hot dry bath and maintained at 60°C for 16 hours and 50 minutes. Hereinafter, this measurement procedure will be referred to as "aging treatment." The degassing tube and the lid of the test tube were removed, and the formic acid aqueous solution was removed with a Pasteur pipette while the immobilized complex catalyst was left in the test tube. The immobilized complex catalyst was then washed three times with 10 mL of ion-exchanged water, and the washing water was removed from the test tube.

[0262] 5 mL of a 4 mol / L formic acid solution was placed in a test tube, which was then capped and bubbled with nitrogen gas for 5 minutes. The test tube was then placed in a water bath at 60°C for 10 minutes and then placed in ice water. The generated gas was collected with a gas-tight syringe and analyzed by gas chromatography to calculate the hydrogen production rate. This measurement result was used as the hydrogen production rate of the immobilized complex catalyst 18 hours after the start of the reaction. The catalytic activity retention rate of the prepared immobilized complex catalyst was calculated using the hydrogen production rate results for 1 hour and 18 hours after the start of the reaction using the following formula:

[0263] Maintenance rate (%) = ((hydrogen production rate after 18 hours of reaction) / (hydrogen production rate after 1 hour of reaction)) × 100

[0264] The evaluation results of catalytic activity are shown in Table 9. Immobilized complex catalysts A-1, B-1, C-1, and D-1 exhibited catalytic activity for formic acid dehydrogenation over a period of 18 hours. The decrease in the hydrogen production rate from 0 to 1 hour after the start of the reaction is thought to be due to the catalyst adsorbed to the silica gel carrier by physical or chemical adsorption, etc., being detached and then expelled during replacement of the formic acid aqueous solution in the test tube or during the washing process with ion-exchanged water. On the other hand, from 1 to 18 hours after the start of the reaction, the decrease in the hydrogen production rate was small, and the catalytic activity retention rate was 80% or higher for all samples, suggesting that good immobilized complex catalysts were produced. Therefore, it was found that the iridium complex catalyst can be firmly immobilized on a silica gel carrier using the immobilized complex catalyst production method, and that the produced immobilized complex catalysts exhibit good catalytic activity and its retention rate.

[0265]

[0266] Example 3 Immobilized complex catalysts D-2, D-3, and D-4 were prepared using the silica gel carrier D described in Example 2. Specific preparation procedures for the immobilized complex catalysts are shown below.

[0267] (Surface Treatment of Silica Gel Carrier) In the preparation of immobilized complex catalysts D-2, D-3, and D-4, surface treatment with a silane coupling agent was carried out under similar conditions. Specifically, in the preparation of immobilized complex catalysts D-2, D-3, and D-4, the silica gel carrier and 3-bromopropyltrimethoxysilane in an amount of 0.3 g per 1 g of silica gel carrier were added to 25 mL of toluene, and the mixture was kept at room temperature for 24 hours. After the surface treatment, the silica gel carrier was washed with toluene at room temperature and air-dried.

[0268] (Immobilization Treatment of Complex Catalyst) In the preparation of immobilized complex catalysts D-2, D-3, and D-4, the immobilization treatment of the complex catalyst was carried out by different methods and under different conditions. Specific preparation methods are shown below.

[0269] (Immobilized Complex Catalyst D-2) Iridium complex catalyst ([(Cp ＊ Ir(4,4'-(NH ２ ) ２ -bpy) (H ２ O) ]SO ４ , A in equation (19) １ H ２ O, R １２ , R １５ Both are NH ２ , [c] ｎ－ is sulfate ion (SO ４ ２－ )) was dissolved in a weakly alkaline (pH 8.3) aqueous sodium bicarbonate solution to obtain an iridium complex catalyst solution with a concentration of 0.8 mg / mL. Subsequently, a surface-treated silica gel carrier that had been air-dried was immersed in the iridium complex catalyst solution and maintained at 90°C for 24 hours, thereby immobilizing the iridium complex catalyst on the silica gel carrier. Thereafter, the silica gel carrier after the catalyst immobilization treatment was immersed in ion-exchanged water, maintained at 90°C for 24 hours for washing, and air-dried to obtain immobilized complex catalyst D-2.

[0270] (Immobilized Complex Catalyst D-3) First, 4,4'-diamino-2,2'-bipyridine (4,4'-(NH ２ ) ２ -bpy, R in equation (52) ５３ , R ５６Both are NH ２ ) was dissolved in a weakly alkaline (pH 8.3) aqueous sodium bicarbonate solution to give a concentration of 0.3 mg / mL of 4,4'-(NH ２ ) ２ A 4,4'-(NH ２ ) ２ The surface-treated silica gel carrier was immersed in the 4,4'-(NH-bpy) solution and maintained at 90°C for 24 hours. Subsequently, the reacted sample was immersed in ion-exchanged water and maintained at 90°C for 24 hours for cleaning. After that, the washed sample was air-dried to remove 4,4'-(NH ２ ) ２ A silica gel carrier on which -bpy was immobilized was obtained.

[0271] Next, an iridium precursor ([Cp ＊ Ir(H ２ O) ３ ]SO ４ , [c] in equation (62) ｎ－ is sulfate ion (SO ４ ２－ )) was dissolved in ion-exchanged water to obtain a 0.6 mg / mL iridium precursor solution. ２ ) ２ The silica gel carrier with -bpy immobilized thereon was immersed in the solution and maintained at 90°C for 24 hours. Subsequently, the reacted sample was immersed in ion-exchanged water and maintained at 90°C for 24 hours for washing. Finally, the washed sample was air-dried to obtain immobilized complex catalyst D-3.

[0272] (Immobilized Complex Catalyst D-4) First, 4,4'-diamino-2,2'-bipyridine (4,4'-(NH ２ ) ２ -bpy) was dissolved in a weakly alkaline (pH 8.3) aqueous sodium bicarbonate solution to give a concentration of 1.7 mg / ml of 4,4'-(NH ２ ) ２ A 4,4'-(NH ２ ) ２The surface-treated silica gel carrier was immersed in the 4,4'-(NH-bpy) solution, kept at 90°C for 24 hours, and then washed with ion-exchanged water to obtain 4,4'-(NH ２ ) ２ A silica gel carrier on which -bpy was immobilized was obtained.

[0273] Next, an iridium precursor ([Cp ＊ Ir(H ２ O) ３ ]SO ４ , [c] in equation (62) ｎ－ is sulfate ion (SO ４ ２－ )) was dissolved in a weakly alkaline (pH 8.3) aqueous sodium bicarbonate solution to obtain an iridium precursor solution with a concentration of 0.5 mg / mL. ２ ) ２ The silica gel carrier on which -bpy was immobilized was immersed and kept at room temperature for 24 hours, and then washed with ion-exchanged water to obtain a silica gel carrier on which an iridium complex catalyst was immobilized.

[0274] Finally, the iridium complex catalyst ([(Cp ＊ Ir(4,4'-(NH ２ ) ２ -bpy) (H ２ O) ]SO ４ , A in equation (19) １ H ２ O, R １２ , R １５ Both are NH ２ , [c] ｎ－ is sulfate ion (SO ４ ２－ )) was further loaded onto the catalyst to obtain immobilized complex catalyst D-4. ＊ Ir(4,4'-(NH ２ ) ２ -bpy) (H ２ O) ]SO ４was dissolved in ion-exchanged water to obtain an iridium complex catalyst solution with a concentration of 0.5 mg / mL. Next, a silica gel carrier on which the iridium complex catalyst was immobilized was immersed in the obtained iridium complex catalyst solution at 90°C for 24 hours to additionally support the iridium complex catalyst. Thereafter, the silica gel carrier was washed with ion-exchanged water and air-dried to obtain immobilized complex catalyst D-4.

[0275] (Measurement IV of formic acid dehydrogenation activity and maintenance of formic acid dehydrogenation activity) The catalytic activities of the prepared immobilized complex catalysts D-2, D-3, and D-4 were evaluated. The evaluation method was the same as in Measurement III of formic acid dehydrogenation activity and maintenance of formic acid dehydrogenation activity in Example 2. However, in this Measurement IV, the aging treatment time was set to 17 hours and 50 minutes, and the hydrogen production rates were measured 0 hours, 1 hour, and 19 hours after the start of the reaction, and the catalytic activity maintenance rate was calculated using the results of the hydrogen production rates at 1 hour and 19 hours after the start of the reaction using the following formula:

[0276] Maintenance rate (%) = ((hydrogen production rate after 19 hours of reaction) / (hydrogen production rate after 1 hour of reaction)) × 100

[0277] The evaluation results of catalytic activity are shown in Table 10. Immobilized complex catalysts D-2, D-3, and D-4 exhibited catalytic activity for formic acid dehydrogenation for 19 hours. The decrease in the hydrogen production rate from 0 hours to 1 hour after the start of the reaction was smallest for immobilized complex catalyst D-3, and the magnitude of catalytic activity 1 hour after the start of the reaction was D-2 > D-4 > D-3, with immobilized complex catalyst D-2 achieving the best results. Furthermore, all samples exhibited high catalytic activity retention rates of 75% or more. Therefore, it was confirmed that the production method for the immobilized complex catalyst used in this experiment is suitable as a method for immobilizing iridium complex catalysts, and that the prepared immobilized complex catalysts exhibited good catalytic performance, with catalytic activity maintained over a long period of time.

[0278]

[0279] [Example 4] Immobilized complex catalysts I-5 and III-1 were prepared using tubular porous glass carrier I and plate-shaped porous glass carrier III, and their catalytic performance was evaluated. The method for producing the immobilized complex catalysts is described below.

[0280] (Porous Glass Carrier I) A porous glass carrier was used that was the same as the porous glass carrier I described in Example 1. The carrier had a tubular shape with a diameter of 4 mm to 9 mm and a wall thickness of 0.8 mm to 1.3 mm.

[0281] (Porous Glass Carrier III) Glass composition 62.5SiO ２ ・28.3B ２ O ３ 9.2Na ２ A glass plate of 0 was cut into a rectangular shape measuring 30 mm x 10 mm and 0.5 mm thick. The glass plate was then placed in alumina powder, sandwiched between alumina plates, and heated in an electric furnace at 600°C for 72 hours in air, resulting in phase separation into a silica-rich phase and a boron oxide-rich phase, yielding a phase-separated glass material. This phase-separated glass material was placed in 0.5 mol / L nitric acid and maintained at 99°C for 96 hours, thereby removing the boron oxide-rich phase and yielding porous glass carrier III. The porous glass carrier III had an average pore size (diameter) of 60 nm and a specific surface area of ​​47 m. ２ The composition of the porous glass carrier III was analyzed to find that it was 96.7SiO ２ ・3.0B ２ O ３ ・0.3Na ２ It was O.

[0282] Subsequently, the porous glass carriers I and III were subjected to surface treatment and a complex catalyst immobilization treatment according to the following procedures and conditions.

[0283] (Surface treatment of porous glass carrier) The porous glass carrier and 3-bromopropyltrimethoxysilane in an amount of 0.2 g per 1 g of the porous glass carrier were added to 25 mL of toluene, and the mixture was kept at room temperature for 24 hours. After the surface treatment, the silica gel carrier was washed with toluene at room temperature and air-dried.

[0284] (Immobilization treatment of complex catalyst) Iridium complex catalyst ([(Cp ＊ Ir(4,4'-(NH ２ ) ２ -bpy) (H ２ O) ]SO ４ , A in equation (19)１ H ２ O, R １２ , R １５ Both are NH ２ , [c] ｎ－ is sulfate ion (SO ４ ２－ )) was dissolved in a weakly alkaline (pH 8.3) aqueous sodium bicarbonate solution to obtain an iridium complex catalyst solution with a concentration of 0.8 mg / mL. Subsequently, the air-dried, surface-treated porous glass carrier was immersed in the iridium complex catalyst solution and maintained at 90°C for 24 hours, thereby immobilizing the iridium complex catalyst on the silica gel carrier. Thereafter, the porous glass carrier after the catalyst immobilization treatment was immersed in ion-exchanged water, maintained at 90°C for 24 hours for washing, and then air-dried to obtain immobilized complex catalysts I-5 (using porous glass carrier I) and III-1 (using porous glass carrier III).

[0285] (Measurement V of formic acid dehydrogenation activity and maintenance of formic acid dehydrogenation activity) The catalytic activities of the prepared immobilized complex catalysts I-5 and III-1 were evaluated. The evaluation method was the same as in Measurement III of formic acid dehydrogenation activity and maintenance of formic acid dehydrogenation activity in Example 2. However, in Measurement V, as in Measurement IV of formic acid dehydrogenation activity and maintenance of formic acid dehydrogenation activity described in Example 3, the aging treatment time was set to 17 hours and 50 minutes, and the hydrogen production rates were measured 0 hours, 1 hour, and 19 hours after the start of the reaction, and the catalytic activity maintenance rate was calculated using the results of the hydrogen production rates 1 hour and 19 hours after the start of the reaction.

[0286] The evaluation results of catalytic activity are shown in Table 11. Immobilized complex catalysts I-5 and III-1 exhibited catalytic activity for formic acid dehydrogenation, and after the catalyst attached to the porous glass support by physical or chemical adsorption or the like was largely detached between 0 and 1 hour after the start of the reaction, the decrease in the hydrogen production rate became smaller, and the catalytic activity retention rate calculated from the hydrogen production rate between 1 and 19 hours after the start of the reaction was 81.6% for immobilized complex catalyst I-5 and 77.6% for immobilized complex catalyst III-1, both of which were good results.

[0287]

[0288] [Example 5] Using the immobilized complex catalyst D-4, the hydrogen and carbon dioxide produced by the formic acid dehydrogenation reaction were evaluated. Specific evaluation details are described below.

[0289] The evaluation method was as follows: first, the same procedure as in Example 2, Measurement III of Formic Acid Dehydrogenation Activity and Formic Acid Dehydrogenation Activity Maintenance was used up to the aging treatment. 41.4 mg of the immobilized complex catalyst was placed in the test tube, and the aging treatment time was 17 hours and 50 minutes. After the aging treatment was completed, the gas vent tube and the cap of the test tube were removed. The formic acid aqueous solution was removed with a pipette while the immobilized complex catalyst remained in the test tube. The immobilized complex catalyst was then washed three times with 10 mL of ion-exchanged water, and the wash water was removed from the test tube. Next, 5 mL of a 4 mol / L formic acid aqueous solution was placed in the test tube, the cap was closed, and nitrogen gas was bubbled through the tube for 5 minutes. The test tube was then placed in a water bath and heated to 60 °C, and evaluation of the hydrogen and carbon dioxide generated was initiated. To evaluate the hydrogen and carbon dioxide in the test tube, gas samples were taken twice with a gas-tight syringe at 10-minute intervals after the start of the reaction, and one sample was used to measure the amount of hydrogen using a gas chromatograph (Shimadzu Corporation, product number "GC-2014"), and the other sample was used to measure the amount of carbon dioxide using a gas chromatograph (GL Sciences, product number "GC3210").

[0290] The measurement results are shown in Table 12. First, it was confirmed that hydrogen and carbon dioxide were generated from formic acid using the immobilized complex catalyst, and the amounts of hydrogen and carbon dioxide in the test tube increased over time. Furthermore, the carbon dioxide / hydrogen gas production ratio was 0.540 10 minutes after the start of the reaction, indicating that more hydrogen was produced than carbon dioxide. This is thought to be due to differences in the solubility of gases in aqueous solutions, with some carbon dioxide dissolving in the formic acid aqueous solution, reducing the amount produced. However, as time passed after the start of the reaction, the carbon dioxide / hydrogen gas production ratio tended to approach 1. This is thought to be due to saturation of carbon dioxide in the formic acid aqueous solution. Therefore, it is thought that approximately equal amounts of hydrogen and carbon dioxide are produced in the formic acid dehydrogenation reaction using the immobilized complex catalyst.

[0291]

[0292] Example 6 (Experiment 1: Evaluation of Immobilized Complex Catalyst Using Continuous Stirred Tank Reactor (Reaction Time: 100 Hours)) Using a continuous stirred tank reactor, the catalytic performance of the immobilized complex catalyst D-1 shown in Example 2 was evaluated, and a hydrogen and carbon dioxide production experiment was carried out over 100 hours.

[0293] The configuration and reaction conditions of the continuous stirred tank reactor 1 are shown in Figure 1 and Table 13, respectively. Specific measurement conditions and procedures were as follows: 1 L of a 3.4 mol / L formic acid solution and 6 g of the immobilized complex catalyst 3 were placed in a reaction vessel 2 placed on a stirrer 9, and then nitrogen gas was introduced to replace the gas in the reaction vessel 2. The 3.4 mol / L formic acid solution was continuously fed into the reaction vessel 2 at a flow rate of 0.4 L / h using the inlet pump 4, and the formic acid solution was continuously discharged from the reaction vessel 2 using the outlet pump 5 so that the formic acid solution in the reaction vessel 2 was always 1 L. The formic acid solution in the reaction vessel 2 was stirred with a stirring blade, and the reaction vessel 2 was heated with a mantle heater 6 to a liquid temperature of 60°C. The output of the mantle heater 6 was controlled with a temperature regulator to maintain a constant liquid temperature at the target temperature. After removing the vapor of the aqueous formic acid solution through a cooling tube 7, the mixed gas of hydrogen and carbon dioxide generated by the formic acid dehydrogenation reaction was measured for its production rate and cumulative gas production amount using a gas meter 8. The reaction time was 100 hours.

[0294]

[0295] The measurement results of the gas production rate are shown in Figure 2, and the measurement results of the cumulative gas production amount are shown in Figure 3. As shown in Figure 2, the gas production rate (L / h) decreased immediately after the start of the reaction and then stabilized after approximately 20 hours. First, the decrease in catalytic performance immediately after the start of the reaction is thought to be due to the desorption of excess catalyst adsorbed on the silica gel carrier. On the other hand, after approximately 20 hours, the decrease in gas production rate became smaller, and catalytic performance was maintained for 100 hours. In addition, the catalytic activity retention rate after 100 hours of reaction was calculated from the linear approximation of the gas production rate data from 20 hours to 100 hours after the start of the reaction. Specifically, linear approximation of the gas production rate yielded an approximate linear equation with a slope of -0.018122 and an intercept of 7.0582. From this approximate linear approximation, the gas production rates at 0 hours and 100 hours were calculated to be 7.06 L / h and 5.25 L / h, respectively. Furthermore, by dividing the calculated gas production rate at 100 hours by the gas production rate at time 0, the catalytic activity retention rate over 100 hours of reaction was estimated to be 74.3%. Furthermore, as shown in Figure 3, the cumulative gas production amount increased with reaction time, reaching approximately 677 L at 100 hours. From the above, the catalytic activity of the prepared immobilized complex catalyst was maintained over 100 hours, and therefore it is considered suitable for the continuous production of hydrogen and carbon dioxide from formic acid and can also be applied to continuous stirred tank reactors used in industrial applications.

[0296] Finally, the immobilized complex catalyst 3 evaluated in the continuous stirred tank reactor 1 was removed from the reactor after 100 hours of reaction, thoroughly washed with water, and air-dried. This sample after 100 hours of reaction was designated as immobilized complex catalyst D-1-R100.

[0297] (Experiment 2: Evaluation of Immobilized Complex Catalyst Using Continuous Stirred Tank Reactor (Reaction Time: 20 Hours)) An additional experiment was conducted using the continuous stirred tank reactor 1 shown in Figure 1. Specifically, the reaction conditions were the same as those shown in Table 13, except that the reaction time was changed to 20 hours, and an immobilized complex catalyst was produced after 20 hours of reaction. The measured gas production rate and cumulative gas production amount (in the range of 0 to 20 hours) roughly agreed with the results of the 100-hour reaction evaluation shown in Figures 2 and 3, and reproducible results were obtained. In addition, the immobilized complex catalyst after 20 hours of reaction was washed with water and air-dried in the same manner as for immobilized complex catalyst D-1-R100, to obtain immobilized complex catalyst D-1-R20.

[0298] (Elemental Analysis of Immobilized Complex Catalyst) Elemental analysis of iridium, carbon, and nitrogen contained in the immobilized complex catalyst was performed. The samples subjected to elemental analysis were three types of immobilized complex catalysts D-1, D-1-R20, and D-1-R100.

[0299] Iridium was analyzed using inductively coupled plasma atomic emission spectroscopy (ICP-AES). Specifically, the sample was first dried, then separated and weighed. The sample was then fused with alkali, dissolved in acid, and diluted to a constant volume with ultrapure water to obtain a test solution, which was then quantitatively analyzed using an ICP-AES apparatus (Agilent Technologies, "Agilent 5110").

[0300] Carbon and nitrogen were analyzed by the combustion method using an elemental analyzer (manufactured by Sumika Chemical Analysis Center, "NC-22F"). First, the sample was pre-treated by drying at 120°C for 2 hours, and then separated and weighed. Next, the sample was burned and oxidized, and the generated gas was introduced into a thermal conductivity detector. Total carbon was determined from the amount of carbon determined from carbon dioxide in the gas, and total nitrogen was determined from the amount of nitrogen obtained by reducing nitrogen oxides. The elemental analysis conditions were a combustion furnace temperature of 900°C, a reduction furnace temperature of 600°C, and oxygen as the supply gas.

[0301] The elemental concentrations (contents) of iridium, carbon, and nitrogen in the analyzed immobilized complex catalyst are shown in Table 14. The concentrations of iridium, carbon, and nitrogen in the immobilized complex catalyst were found to show a trend similar to the trend in the decrease in gas production rate evaluated in a continuous stirred tank reactor. Therefore, the decrease in gas production rate was small, particularly from 20 hours to 100 hours, and catalytic activity was maintained. This is thought to be due to the fact that the iridium complex in the immobilized complex catalyst was immobilized on the surface of the silica gel carrier.

[0302]

[0303] (Evaluation of catalyst turnover frequency) The catalyst turnover frequency (TOF) of the immobilized complex catalysts D-1-R20 and D-1-R100 for the formic acid dehydrogenation reaction was calculated from the iridium concentration of the immobilized complex catalyst shown in Table 14, the gas production rate after 20 hours of reaction measured in Experiment 2, and the gas production rate after 100 hours of reaction measured in Experiment 1. The results are shown in Table 15. As shown in Table 15, the TOF was greater for the immobilized complex catalyst D-1-R100. This suggests that it takes time for the immobilized complex catalyst to become activated, and it is thought that the immobilized complex catalyst was not completely activated 20 hours after the start of the reaction.

[0304]

[0305] (Evaluation by solid-state nuclear magnetic resonance (NMR) method) The immobilized complex catalyst D-1-R100 was subjected to solid-state NMR measurement. First, the sample was crushed in an agate mortar and then filled into a zirconia sample tube (sample tube diameter: 7 mm). Using a digital NMR device (manufactured by Bruker Japan, "AVANCE III 400 type"), the solid-state NMR was measured by cross polarization magic angle spinning (CPMAS). ２９ Si-CPMAS measurement was performed. The standard substance was hexamethyltricyclosiloxane, and its silicon signal was set to -9.7 ppm. Specific measurement conditions are shown in Table 16.

[0306]

[0307] ２９ ​As a result of Si-CPMAS measurement, Q ２ , Q ３ , Q ４ , T ３ The chemical shift value of the observed peak was Q ２ is -92 ppm, Q ３ is -101 ppm, Q ４ is -112 ppm, T ３ was -67 ppm. ２ , Q ３ , Q ４ is considered to be a peak derived from the silica gel carrier used in the immobilized complex catalyst. ３ indicates a Si atom with three siloxane bonds (Si—O—Si) and one Si—C bond, it is believed that the Si atom in the linker portion of the immobilized complex catalyst is trifunctionally bonded via three different Si atoms and an oxygen atom. Furthermore, it is believed that this state of bonding between the linker portion and the support firmly immobilized the iridium complex catalyst on the silica gel support, resulting in high catalytic activity and maintenance rate over 100 hours.

[0308] (Evaluation by pyrolysis gas chromatography mass spectrometry (GC-MS)) A gas chromatograph mass spectrometer (Shimadzu Corporation, "GCMS QP-2010Ultra") connected to a pyrolyzer (Frontier Labs, "EGA / PY-3030D") at the sample introduction port was used to measure fragments generated by the thermal decomposition of immobilized catalysts D-1, D-1-R20, and D-1-R100. In addition, in the gas chromatograph mass spectrometer, a Frontier Labs, "Ultra ALLOY UA5 (MS / HT)-30M-0.25F" separation column was used. The measurement procedure was as follows: first, 1 mg to 5 mg of the immobilized complex catalyst was weighed and placed in a sample cup, which was then inserted into the ionizer. The pyrolyzer was then heated from 70°C to 600°C at a rate of 20°C / min, and after reaching 600°C, it was maintained at that temperature for an additional 2 minutes. The gas generated by pyrolysis was then injected into a gas chromatograph mass spectrometer for analysis. The obtained measurement data was analyzed using the software provided with the gas chromatograph mass spectrometer. Specifically, mass spectra of the peaks in the pyrogram were acquired, and the compounds of each peak were identified by a similarity search using a library. The NIST mass spectral library (NIST08, NIST08s) was used as the library.

[0309] It is believed that the following fragments are generated from the immobilized complex catalyst by pyrolysis GC-MS. Specifically, relatively large peaks that were detected were thought to be those of carbon dioxide, 1-(2-aminoethyl)aziridine, (2S)-2-amino-N-ethylpropanamide, N-methyl-1-octanamine, pentane, 2-methyl-1-pentene, methylcyclopentane, cyclohexane, tetrahydrofuran, benzene, 2,4-dimethyl-1-heptene, 3,7-dimethyl-1-octene, 4-methyl-1-heptene, 1,2,3,4,5-pentamethylcyclopentadiene, 1,2,3,4-tetramethyl-5-methylene-1,3-cyclopentadiene, 1-methyl-4-(1-methylethenyl)benzene, 1-methyl-2-isopropenylbenzene, hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, and the like. Nitrogen-containing organic compounds and Cp that are thought to be derived from the organic ligands of the immobilized complex catalyst ＊ It was possible to identify a five-membered ring hydrocarbon compound that is thought to be the origin of the compound.

[0310] (Evaluation by Temperature-Programmed Oxidation Measurement) Temperature-programmed oxidation measurements were performed on the immobilized complex catalysts D-1, D-1-R20, and D-1-R100 to measure the temperature profile of carbon dioxide generated by the oxidation reaction. The measurement method involved first filling 0.1 g of the immobilized complex catalyst into a quartz tube, and then inserting the quartz tube into an electric heating furnace. Next, while a gas with an air composition (nitrogen:oxygen = 80:20) was circulated through the quartz tube at 100 mL / min, the temperature of the electric heating furnace was increased from room temperature to 800°C at 10°C / min. The gas generated by the temperature-programmed oxidation was passed through a Pt catalyst reactor heated to 350°C, and then analyzed by a mass flow meter and ND-IR CO ２ The gas flow rate and carbon dioxide concentration were measured using a gas sensor (manufactured by Vaisala, "GMP252"), and the rate of carbon dioxide production (µmol / (min·g)) at each temperature was calculated.

[0311] The results of temperature-programmed oxidation measurements of the immobilized complex catalysts D-1, D-1-R20, and D-1-R100 are shown in Figures 4, 5, and 6, respectively. Carbon dioxide peaks due to oxidation were detected, and three peaks were confirmed in all samples. The peak temperatures observed were 353°C, 446°C, and 512°C for the immobilized complex catalyst D-1, 365°C, 440°C, and 500°C for the immobilized complex catalyst D-1-R20, and 374°C, 444°C, and 500°C for the immobilized complex catalyst D-1-R100. In all immobilized complex catalysts, the main peak was the lowest-temperature peak, and the peak intensities showed the following relationship: D-1 > D-1-R20 > D-1-R100. It was also found that the peak temperature of the main peak shifted to higher temperatures in the order of D-1, D-1-R20, and D-1-R100. Considering the TOF results of the immobilized complex catalysts shown in Table 15, this peak shift is thought to be related to the activation of the immobilized complex catalysts by immersion in a formic acid solution.

[0312] Next, the carbon amount of the immobilized complex catalyst was calculated from the obtained results of the temperature-programmed oxidation measurement. ２ / N ２ ) to calibrate the detector sensitivity, and the measurement signal is CO ２ The gas flow rate (mL / min) after passing through the detector and the CO concentration (ppm) were recorded every second. ２ From the concentration, CO produced per unit time ２ The amount (μmol / min) of CO produced during the measurement is calculated and displayed as the amount (μmol / (min g)) per measurement sample amount (g) on ​​the vertical axis of the figure. Therefore, by integrating this vertical axis value over the entire measurement time and multiplying it by the sample amount (g), the total CO produced during the measurement can be calculated. ２ From room temperature to 800°C, all carbon in the sample is burned and CO ２ Therefore, the total CO ２The number of moles obtained as the amount is equal to the number of moles of carbon in the sample, and by converting this to mass and dividing it by the measured mass of the sample, the carbon amount (% by mass) of the immobilized complex catalyst is obtained. The carbon amounts of the immobilized complex catalysts calculated using the above procedure were 0.73% by mass for D-1, 0.26% by mass for D-1-R20, and 0.20% by mass for D-1-R100. It was found that these results roughly matched the carbon concentrations measured by the combustion method (see Table 14).

[0313] DESCRIPTION OF SYMBOLS 1... Continuous stirred tank reactor 2... Reaction vessel 3... Immobilized complex catalyst 4... Liquid feed pump for feeding 5... Liquid feed pump for discharging 6... Mantle heater 7... Cooling tube 8... Gas meter 9... Stirrer

Claims

1. An immobilized complex catalyst in which a support and a complex catalyst are bonded via a linker moiety, wherein the support and the complex catalyst are bonded via the linker moiety as shown in the following formula (1) and / or the following formula (2), and the complex catalyst and the linker moiety are bonded via an amine bond. [In the formula (1) and the formula (2), L ｐ M ｋ represents the complex catalyst bound to the linker moiety, and L ｐ M ｋ The portion other than the above represents a complex formed by binding the linker portion and the support, and in the complex catalyst, L ｐ represents p ligands, which may be the same or different; M ｋ represents k metal atoms, which may be the same or different, and p and k are each an integer of 1 to 4; and in the complex, R １ ~R ６ each independently represents a halogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, a hydroxy group, -O-* (* represents the support, - represents a bond, and O represents an oxygen atom), or -O-. (- represents another Si atom in the linker part of the same immobilized complex catalyst, or a Si atom in a linker part of another immobilized complex catalyst, - represents a bond, and O represents an oxygen atom) (provided that R in formula (1) １ ~R ３ and R in the formula (2) １ ~R ６ wherein at least one of the formulas is —O—* (* represents the carrier), and the linker portion and the carrier are bonded together), Z １ and Z ２ each independently represents a substituted aliphatic group, an unsubstituted aliphatic group, a substituted aromatic group, or an unsubstituted aromatic group; Q １ and Q ２ are each independently a hydrogen atom, an alkyl group, or a linker portion represented by the following formula (3), or the complex: [In the formula (3), R ７ ~R ９ each independently represents a halogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, a hydroxy group, -O-* (* represents the support, - represents a bond, and O represents an oxygen atom), or -O-. (- represents another Si atom in the linker portion of the same immobilized complex catalyst, or a Si atom in a linker portion of another immobilized complex catalyst, - represents a bond, and O represents an oxygen atom), and Z ３ represents a substituted aliphatic group, an unsubstituted aliphatic group, a substituted aromatic group, or an unsubstituted aromatic group, and the rightmost bond in formula (3) is bonded to the nitrogen atom in formula (1) or (2).

2. The immobilized complex catalyst according to claim 1, wherein the complex catalyst comprises, as an active ingredient, a complex catalyst represented by any one of the following formulas (4) to (7) or a salt of the complex catalyst, or an isomer of the complex catalyst represented by any one of the following formulas (4) to (7) or a salt of the isomer: [In the formulas (4) to (7), M is iridium, rhodium, ruthenium, cobalt, osmium, nickel, iron, palladium, platinum, or gold; among the ligands, L is an aromatic anionic ligand or an aromatic ligand; when L has a substituent, the number of the substituents is 1 or 2 or more; among the other ligands, A １ Is, H ２ O, hydride, formate ion, hydroxide ion, or alkoxide ion; L and A １ In the ligand other than the above, the bond order between the elements forming the ligand is a single bond or a double bond, the heterocycle forming the ligand is an aromatic ring or a non-aromatic ring, and X １ ~X ２８ are each independently a carbon atom, a nitrogen atom, an oxygen atom, or a sulfur atom, and R in the formula (4) １０ ~R １７ , R in the formula (5) １８ ~R ２４ , R in the formula (6) ２５ ~R ３０ and R in the formula (7) ３１ ~R ３４ In each formula, at least one is bonded to the linker portion by an amine bond (provided that X ｉ (i is any one of 14 to 19 and 22 to 24) is a nitrogen atom, the nitrogen atom may form an amine bond with the linker moiety.), R １０ ~R ３５ Among these, those which are not bonded to the linker moiety via an amine bond are each independently a hydrogen atom, an alkyl group, a hydroxy group, an alkoxy group, a nitro group, a halogeno group, a sulfone group, a carboxylic acid group, an amino group, an alkylamino group, a phenyl group, or an adjacent R ｉ (i is 10 to 34) form a ring, and Q ３ is an oxygen atom, a sulfur atom, or a selenium atom, and m and n are each a positive integer or 0 and indicate an ionic valence; [c] ｎ－ is any one of hydroxide ion, sulfate ion, chloride ion, bromide ion, nitrate ion, and hexafluorophosphate ion.

3. The immobilized complex catalyst according to claim 1 or 2, wherein the complex catalyst comprises, as an active ingredient, a complex catalyst represented by any one of the following formulas (8) to (11) or a salt of the complex catalyst, or an isomer of the complex catalyst represented by any one of the following formulas (8) to (11) or a salt of the isomer: [In the formulas (8) to (11), one of the ligands is a pentamethylcyclopentadienyl ligand, and among the other ligands, A １ Is, H ２ O, hydride, formate ion, hydroxide ion, or alkoxide ion; pentamethylcyclopentadienyl ligand and A １ In the ligand other than the above, the bond order between the elements forming the ligand is a single bond or a double bond, the heterocycle forming the ligand is an aromatic ring or a non-aromatic ring, and X １ ~X ２８ are each independently a carbon atom, a nitrogen atom, an oxygen atom, or a sulfur atom, and R in the formula (8) １０ ~R １７ , R in the formula (9) １８ ~R ２４ , R in the formula (10) ２５ ~R ３０ and R in the formula (11) ３１ ~R ３４ In each formula, at least one is bonded to the linker portion by an amine bond (provided that X ｉ (i is any one of 14 to 16, 17 to 19, and 22 to 24) is a nitrogen atom, the nitrogen atom may form an amine bond with the linker moiety), R １０ ~R ３５ Among these, those which are not bonded to the linker moiety via an amine bond are each independently a hydrogen atom, an alkyl group, a hydroxy group, an alkoxy group, a nitro group, a halogeno group, a sulfone group, a carboxylic acid group, an amino group, an alkylamino group, a phenyl group, or an adjacent R ｉ (i is 10 to 34) form a ring, and Q ３ is an oxygen atom, a sulfur atom, or a selenium atom, and m and n are each a positive integer or 0 and indicate an ionic valence; [c] ｎ－ is any one of hydroxide ion, sulfate ion, chloride ion, bromide ion, nitrate ion, and hexafluorophosphate ion.

4. The immobilized complex catalyst according to claim 1 or 2, wherein the complex catalyst comprises, as an active ingredient, a complex catalyst represented by any one of the following formulas (12) to (18) or a salt of the complex catalyst, or an isomer of the complex catalyst represented by any one of the following formulas (12) to (18) or a salt of the isomer of the complex catalyst: [In the formulas (12) to (18), one of the ligands is a pentamethylcyclopentadienyl ligand, and among the other ligands, A １ Is, H ２ O, hydride, formate ion, hydroxide ion, or alkoxide ion; pentamethylcyclopentadienyl ligand and A １ In the ligand other than the above, R １０ ~R １７ , R in the formula (13) １８ ~R ２４ , R in the formula (14) １８ and R ２０ ~R ２４ , R in the formula (15) １８ ~R ２４ , R in the formula (16) １８ ~R ２４ , R in the formula (17) ２５ ~R ３０ and R in the formula (18) ２５ ~R ３０ At least one of the R ２２ and R in (17) and (18) above. ２７ and R ２８ is bonded to the linker portion via an amine bond, R ｉ (i is 22, 27, or 28) may be bonded to a nitrogen atom of the five-membered aromatic heterocyclic ring, which may form an amine bond with the linker moiety.), R １０ ~R ３０ Among these, those that are not bonded to the linker portion via an amine bond are each independently a hydrogen atom, an alkyl group, a hydroxy group (—OH), an alkoxy group (—OR), a nitro group, a halogeno group, a sulfone group, a carboxylic acid group, an amino group, an alkylamino group, a phenyl group, or an adjacent R ｉ (i is 10 to 30) form a ring together, m and n are each a positive integer or 0 and indicate an ionic valence, [c] ｎ－ is any one of hydroxide ion, sulfate ion, chloride ion, bromide ion, nitrate ion, and hexafluorophosphate ion.

5. The immobilized complex catalyst according to claim 1 or 2, wherein the complex catalyst comprises, as an active ingredient, a complex catalyst represented by any one of the following formulas (19) to (22) or a salt of the complex catalyst, or an isomer of the complex catalyst represented by any one of the following formulas (19) to (22) or a salt of the isomer of the complex catalyst: [In the formulas (19) to (22), one of the ligands is a pentamethylcyclopentadienyl ligand, and among the other ligands, A １ Is, H ２ O, hydride, formate ion, hydroxide ion, or alkoxide ion; pentamethylcyclopentadienyl ligand and A １ In the ligand other than the above, R １２ and R １５ , R in the formula (20) １２ and R １５ , R in the formula (21) １８ , R ２０ , and R ２２ and R in the formula (22) ２７ and R ２８ In each formula, at least one is bonded to the linker portion via an amine bond (provided that R ２２ and R in the formula (22) ２７ and R ２８ is bonded to the linker portion via an amine bond, R ｉ (i is 22, 27, or 28) may be bonded to the linker moiety via an amine bond at the nitrogen atom of the five-membered aromatic heterocyclic ring.), R １２ , R １５ , R １８ , R ２０ , R ２２ , R ２７ , and R ２８ [c], each of the groups not bonded to the linker moiety via an amine bond is independently a hydrogen atom, an alkyl group, a hydroxy group, an alkoxy group, a nitro group, a halogeno group, a sulfone group, a carboxylic acid group, an amino group, an alkylamino group, or a phenyl group, and m and n are each a positive integer or 0 and represent an ionic valence. ｎ－ is any one of hydroxide ion, sulfate ion, chloride ion, bromide ion, nitrate ion, and hexafluorophosphate ion.

6. The immobilized complex catalyst according to claim 1 or 2, wherein the support has hydrophilic groups on the surface.

7. The immobilized complex catalyst according to claim 1 or 2, wherein the support comprises any one of porous glass, silica gel, and mesoporous silica.

8. The immobilized complex catalyst according to claim 1 or 2, which is used as a heterogeneous catalyst in the liquid or gas phase.

9. The immobilized complex catalyst according to claim 1 or 2, which is used for the decomposition of formic acid and the production of hydrogen and / or carbon dioxide.

10. An immobilized complex catalyst in which a complex catalyst is supported on a carrier, the complex catalyst comprising at least one metal element selected from the group consisting of iridium, rhodium, ruthenium, cobalt, osmium, nickel, iron, palladium, platinum, and gold, and a ligand containing a five-membered ring ligand and / or an amine, the immobilized complex catalyst being capable of exhibiting a chromatographically significant peak obtained by solid-state NMR measurement. ２９ In the Si-NMR spectrum, T ３ The immobilized complex catalyst has a peak.

11. The immobilized complex catalyst according to claim 10, wherein the immobilized complex catalyst contains, by mass %, more than 0% to 5% of at least one metal element selected from the group consisting of iridium, rhodium, ruthenium, cobalt, osmium, nickel, iron, palladium, platinum, and gold.

12. The immobilized complex catalyst according to claim 10 or 11, which contains, by mass %, from 0% to 5% Ir, from 0% to 10% C, and from 0% to 5% N.

13. The carrier has a crystalline and / or glass composition of SiO ２ The immobilized complex catalyst according to claim 10 or 11, comprising:

14. The carrier has an average pore diameter of 1 nm to 1000 nm and a specific surface area of ​​1 m ２ / g~1500m ２ The immobilized complex catalyst according to claim 10 or 11, wherein the molecular weight of the immobilized complex catalyst is 1 / g.

15. The immobilized complex catalyst according to claim 10 or 11, wherein the five-membered ring ligand is a pentamethylcyclopentadienyl anion and / or a pentamethylcyclopentadienyl derivative.

16. The immobilized complex catalyst according to claim 1 or 2, which is used for producing hydrogen and / or carbon dioxide from formic acid.

17. A method for producing an immobilized complex catalyst, comprising: a surface modification step of introducing a linker moiety capable of forming an amine bond with a ligand onto the surface of a support using a silane coupling agent; an amine bonding step of bonding the linker moiety and the ligand via an amine bond; and a catalyst synthesis step of coordinating the ligand bonded to the linker moiety via the amine bond to a metal atom of a complex catalyst precursor, thereby synthesizing a complex catalyst.

18. A method for producing an immobilized complex catalyst, comprising: a surface modification step of introducing a linker moiety capable of forming an amine bond with the complex catalyst onto the surface of a carrier using a silane coupling agent; and a catalyst immobilization step of bonding the linker moiety and the complex catalyst via an amine bond.

19. The method for producing an immobilized complex catalyst according to claim 17 or 18, wherein the silane coupling agent is represented by the following formula (40): [In the formula (40), R ４９ represents a halogeno group or an alkoxy group, and R ５０ and R ４８ each independently represents a halogeno group, an alkoxy group, an alkyl group, an alkenyl group, or an alkynyl group; Z ４ represents a substituted aliphatic group, an unsubstituted aliphatic group, a substituted aromatic group, or an unsubstituted aromatic group; X ２９ represents a halogeno group.

20. The method for producing an immobilized complex catalyst according to claim 17 or 18, wherein the ligand or the ligand of the complex catalyst is represented by the following formula (41) to formula (44), and the amino group and / or the five-membered ring amine structure of the ligand or the ligand of the complex catalyst is bonded to the linker part via an amine bond. [In the formulas (41) to (44), the bond order between the elements forming the ligand is a single bond or a double bond, the heterocycle forming the ligand is an aromatic ring or a non-aromatic ring, and X ３０ ~X ５７ are each independently a carbon atom, a nitrogen atom, an oxygen atom, or a sulfur atom, and R in the formula (41) ５１ ~R ５８ , R in the formula (42) ５９ ~R ６５ , R in the formula (43) ６６ ~R ７１ and R in the formula (44) ７２ ~R ７５ In each formula, at least one is an amino group (provided that in each of the formulas (42) and (43), X ｉ (i is any one of 43 to 48 and 51 to 53) is a nitrogen atom, and when there is at least one amine structure in which a hydrogen atom is bonded to the nitrogen atom, R ５９ ~R ６５ and R in the formula (43) ６６ ~R ７１ may not have an amino group in each formula), R ５１ ~R ７６ Among these, those that are not amino groups are each independently a hydrogen atom, an alkyl group, a hydroxy group, an alkoxy group, a nitro group, a halogeno group, a sulfone group, a carboxylic acid group, an amino group, an alkylamino group, a phenyl group, or adjacent R ｉ (i is 51 to 75) form a ring, and Q ８ is an oxygen atom, a sulfur atom, or a selenium atom.

21. A method for producing an immobilized complex catalyst according to claim 17 or 18, comprising a catalyst additional immobilization step of additionally immobilizing a complex catalyst.

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